The Messenger

No. 148 – June 2012 Recent progress on the E-ELT the progress on Recent planetary of nebulae catalogue image New X-shooter with star spectroscopy Massive Paranal for energy plans Renewable Telescopes and Instrumentation

Recent Progress Towards the European Extremely Large Telescope (E-ELT)

Alistair McPherson1 cepted by the ESO Council and awaits adopted by the ESO Council as the base- Roberto Gilmozzi1 the decision on the start of construction. line for the new 39-metre E-ELT. Jason Spyromilio1 Markus Kissler-Patig1 Suzanne Ramsay1 The European Extremely Large Telescope Science capabilities (E-ELT) design has evolved significantly since the last report in The Messenger A primary concern with respect to the 1 ESO (Spyromilio et al., 2008) and here we aim new baseline for the telescope was to update the community on the activities its impact on the scientific capabilities. within the E-ELT Project Office during The E-ELT Science Office, together ESO contributors to this work include: the past few years. The construction pro- with the Science Working Group studied Jose Antonio Abad, Luigi Andolfato, Robin Arsenault, posal prepared for the ESO Council the impact on the science of the various Joana Ascenso, Pablo Barriga, Bertrand Bauvir, Henri Bonnet, Martin Brinkmann, Enzo Brunetto, has been widely publicised and is availa- modifications to the baseline design 1 3 Mark Casali, Marc Cayrel, Gianluca Chiozzi, Richard ble on the ESO website . using the Design Reference Mission and Clare, Fernando Comerón, Laura Comendador Design Reference Science Cases4 as Frutos, Ralf Conzelmann, Bernard Delabre, Alain In the second half of 2010, the E-ELT benchmarks for the evaluation. Delorme, Canio Dichirico, Philippe Dierickx, Martin Dimmler, Mark Downing, Toomas Erm, Michael programme underwent a series of techni- Esselborn, Robert Frahm, Christoph Frank, Enrico cal and managerial reviews that pro- The diameter of the primary mirror is Fedrigo, Giorgio Filippi, Peet Fourie, Fernando Gago, vided a strong endorsement of the con- the most fundamental and most impor- Paolo Ghiretti, Frederic Gonte, Juan-Carlos struction project. The activities under tant characteristic of any telescope Gonzales, Serge Guniat, Carlos Guirao, Stephane Guisard, Juan-Pablo Haddad, Wolfgang Hacken- taken during the phase B (2007–2010) system, but particularly for an adaptive berg, Volker Heinz, Renate Hinterschuster, Ronald were thoroughly reviewed by a board of optics assisted telescope, as it deter- Holzlöhner, Richard Hook, Norbert Hubin, Lisselotte external experts in September 2010 mines both its diffraction-limited spatial Jochum, Andreas Jost, Noé Kains, Dimitrios (see Kissler-Patig, 2010). The executive resolution as well as its photon-collecting Kalaitzoglou, Robert Karban, Markus Kasper, Hans- Ulrich Käufl, Lothar Kern, Mario Kiekebusch, Franz summary of the board report has been power. These properties may combine 2 Koch, Bertrand Koehler, Johann Kolb, Nick Korn available for some time . The short differently depending on the scientific weibel, Maximilian Kraus, Paolo La Penna, Miska version is that “it [was] the unanimous goal, as well as the observational and LeLouarn, Samuel Lévêque, Stefan Lewis, Jochen conclusion of the review board that the astrophysical circumstances. The result Liske, Jean-Louis Lizon, Gianluca Lombardi, Antonio Longinotti, Fernando Luco, Christian Lucuix, Pierre- technical maturity of the design of the is that there can be many different Yves Madec, Enrico Marchetti, Juan Marrero, Javier E-ELT was sufficient to warrant the pro- ways in which a given science case may Marti, Jorge Melnick, Katia Montironi, Christian gramme entering the construction depend on the diameter. Muckle, Michael Mueller, Julio Navarette, Helène phase”. Moreover, the “E-ELT budget was Neuville, Lothar Noethe, Paolo Padovani, Luca Pasquini, Jérôme Paufique, Lorenzo Pettazzi, Marco highly cost-effective” and the “FEED At the highest level we may distinguish Quattri, Jutta Quentin, Andrea Richichi, Robert methodology had been highly effective in between the following three classes Ridings, Mark Robinson, Michael Rosa, Stefan generating reliable cost estimates” (for a of science cases: (i) cases where science Sandrock, Pierre Sansgasset, Marc Sarazin, Michael definition of FEED see below p. 8). is irretrievably lost by reducing the tele- Schneermann, Dominik Schneller, Babak Sedghi, Ralf Siebenmorgen, Isabelle Surdej, Arek Swat, scope diameter; (ii) cases where the loss Donald Tait, Roberto Tamai, Arno van Kesteren, Elise However, the final cost estimate at the of telescope diameter can be compen- Vernet, Joël Vernet, Gianluca Verzichelli, Anders end of phase B was € 200 million above sated for by increasing the observing Wallander, Yves Wesse, Natalia Yaitskova, Michele the top end of the target. The project was time or adjusting some other observa- Zamparelli. asked to consider whether any significant tional parameter; (iii) cases that are not cost savings could be delivered without affected by the reduction of the telescope The European Extremely Large Tele- compromising the scientific capabilities of diameter at all. scope (E-ELT) has evolved over the the telescope. Unfortunately the answer last few years since the phase B review to this question was no. Some reduction The unique spatial resolution of the E-ELT of the 42-metre design. While the in scope from the 42-metre aperture is one of its defining characteristics and design was strongly endorsed, the cost would be necessary. On the other hand, hence it is not surprising that many of the exceeded the maximum envelope and following a four-year design development science cases that have been proposed a re-baselining was implemented by phase the project was also aware of for the E-ELT aim to exploit this feature. the Project Office. The extent and rami- areas where technical and programmatic All cases that require the E-ELT resolution fications of the new design are outlined risks existed. Realistic funding scenarios to disentangle their targets from other including scientific, engineering and gave an earliest possible start for the nearby sources will be forced to adopt managerial aspects. Prototyping activi- project in 2012 and therefore there was less demanding goals for the 39-metre ties of some of the components are time to work on mitigating those risks. E-ELT than originally envisaged for the described and the first light instruments The Project Office undertook to explore 42-metre design. This observational sce- have been selected. The new baseline cost saving and risk mitigation options nario encompasses a vast range of sci- for the 39-metre E-ELT has been ac during 2011. These changes have been ence cases, and prominent examples

2 The Messenger 148 – June 2012 include the direct detection of exoplanets independent of diameter for the specific work. Reducing the cost of the dome (all high-contrast imaging applications regime under consideration here, i.e. required a reduction in the overall volume depend particularly strongly on the diam- when going from the 42-metre to the occupied by the telescope and reducing eter), the study of the resolved stellar 39-metre aperture. This class does not the cost of all other components of the populations of other galaxies, and studies encompass many cases, but one promi- programme (excluding instrumentation) of supermassive black holes and their nent example is the detection of low- also required a reduction in the dimen- environments in the centre of our own mass exoplanets using the radial velocity sions of the telescope. and other galaxies. method. The 42-metre E-ELT design was based The other subcategory in this class of The overall loss of scientific efficiency on a three-mirror anastigmat used on- irretrievable loss contains cases where resulting from the reduction of the E-ELT axis with two folding flat mirrors extract- the observing time cannot arbitrarily diameter depends of course on how ing the beam to a suitable Nasmyth focus be extended, even in principle. Among the observing time will be distributed (Spyromilio et al., 2008). This design was such cases are included observations among the various science cases, each driven by the requirement for a Nasmyth of non-recurring transient events, such following different scaling laws. This is focus, that the telescope be adaptive as gamma-ray bursts (GRBs) or super difficult to know a priori, but it is reason and the large diameter. These three basic novae, and short recurring events with able to assume that the E-ELT will spend requirements, combined with a number very long periods between repetitions, much of its time doing science that of engineering risks (e.g., the maximum such as some eclipses or transits. In all of depends on the power of the diameter to size of the deformable mirror that was these cases the reduction of diameter the squared or fourth power, resulting in viable within cost and schedule con- will lead to a loss of signal-to-noise (S/N) an overall loss of efficiency in the range of straints), confined the parameter space. that cannot be compensated for by in 20 to 35%. Our competitors have chosen more creasing the integration time. classical designs: Ritchey-Chrétien (RC) In addition to assessing the overall loss in the case of the Thirty Metre Telescope The second class of science cases con- of scientific efficiency, it was also evalu- (TMT) and Gregorian in the case of the tains those that are limited by the S/N ated whether any individual science Giant Magellan Telescope (GMT). We that is achievable on their targets, and cases are rendered completely infeasible considered whether a smaller telescope where the S/N is not dominated by by the reduction in the E-ELT diameter, would warrant completely new thinking (diameter-independent) astrophysical in the sense that the diameter is now in the optical design, but concluded that error sources or systematic uncertainties below some critical threshold value for the incorporation of adaptive optics in (astrophysical, instrumental, or other- these cases. To summarise the result of the telescope is a prerequisite for the wise). To a large extent these cases prin- this analysis: of all the major science dimensions that we were considering. In cipally exploit the other key characteristic cases for the E-ELT, the one that is most addition to correcting the ground layer of the E-ELT, namely its unique photon- severely affected by the reduction of of atmospheric turbulence, the inclusion collecting power. The feature that is com- the telescope diameter is the direct imag- of an adaptive element in the telescope mon to all of these cases, and which ing of Earth-analogue exoplanets. Never- optical train allows us to manage the sets them apart from those in the first theless, the overall conclusion is that aberrations of the telescope under the class, is that a decrease in diameter can none of the major science cases for the disturbances of wind and gravity. be compensated for by increasing the E-ELT must be completely abandoned, observing time in order to achieve the and that, on the whole, the E-ELT science The design was therefore iterated around same result with the 39-metre as with the case remains intact and does not require the existing solution. Reducing the vol- 42-metre E-ELT. Again, this class encom- any major revision. ume of the telescope could be achieved passes a vast range of science cases. by making the primary faster (lowering Prominent examples include most studies the f-ratio). However, consideration of high-redshift galaxies, investigations The new telescope needed to be given to the difficulty of of the stellar populations in the Galaxy making the segments and the secondary and the search for possible variations of The costs of the E-ELT are roughly divided mirror. After some investigation it was the fundamental physical constants. between: 40% for the dome and main considered that making the telescope structure; 40% for the opto-mechanics; somewhat smaller and faster would pro- Finally, the third class of science cases 10% for the instrumentation; and 10% for vide us with cost savings in the dome, contains those cases that are limited by the rest. From this breakdown it should the main structure and the primary mirror, (diameter-independent) astrophysical be obvious that no individual component as well as reductions in manufacturing error sources or systematic uncertainties, would deliver the significant cost saving and performance risks. or where the reduction of diameter can necessary to bring the telescope within be compensated for by adjusting param- the required cost envelope. Removing the two outer rings of the eters that have essentially no impact primary mirror segments results in a on the science. We stress that we are The natural choice of reducing everything new telescope diameter of 38.54 metres only referring to cases that are quasi- but the telescope diameter could not for segments that are used fully and

The Messenger 148 – June 2012 3 Telescopes and Instrumentation McPherson A. et al., Recent Progress towards the E-ELT

39.1 metres if one includes the few seg- have maintained, to the maximum extent of the Nasmyth platforms, the telescope ments that are illuminated for 80% of possible, the linear dimensions of the main structure has lost a lot of weight their surface. The two rings accounted quaternary adaptive mirror. Effectively this (several hundreds of tonnes of steel) and for approximately 200 segments from the provides a somewhat denser actuator engineering complexity. original 984 installed in the telescope. spacing in comparison to the 42-metre The cost saving unfortunately is not a design, as approximately the same num- straight percentage of segment number ber of actuators now cover a smaller pri- Design activities as the facility costs (building the factory mary mirror. to produce the mirror segments and It has been challenging to evaluate these equipping it with the necessary polishing In order to maintain the field of view of the ideas and to bring the E-ELT project robots, etc) are relatively invariant at this telescope with a smaller secondary, the with this new concept to a comparable scale of production. However, the risk telescope primary mirror is now faster at level of engineering as the phase B for of achieving the production goals and f/0.9. However the difficulty in polishing the 42-metre design had achieved. In timescales are theoretically much reduced the segments of the primary mirror is particular this re-baselining was to be by the smaller number of segments. comparable between the two designs. performed within one calendar year and with limited resources. The Project Office Having lost three metres of diameter on The aspheric coefficients of the smaller placed a series of delta phase B con- the primary mirror of the telescope, we secondary mirror are different but remain tracts to update the previous design. A targeted cost savings in the other com- within the polishing regime considered revision of the dome for the new param ponents that should be at least as dra- for the 42-metre baseline 6-metre mirror. eters and a revision of the main struc- matic. The dimensions of the dome were The polishing solution proposed by the ture were contracted to the firms that had reduced further as we shrank the tele- ESO contractors for the convex 6-metre developed the original concepts. scope Nasmyth platforms by five metres mirror employed transmission elements, on each side, thereby reducing the dome known as matrices, for the metrology. The new dome is simplified relative to diameter by more than 10%. The matrices are large optical elements the phase B concept in a number of that more or less match the radial curva- critical areas. After an evaluation by the In the redesign process, the project con- ture and local aspheric departure of contractors and ESO of the erection sidered which risks could be further the mirror and cover a fraction of the sur- sequence for the dome and the main mitigated or reduced. The large second- face. The mirror is then rotated under structure, it became apparent that the ary mirror (a convex 6-metre in the the matrix while the cavity between the large 30 × 17-metre loading door, fore- 42-metre case) posed a series of inter matrix and the polished mirror surface seen to allow large telescope compo- esting manufacturing challenges and creates the interferometric cavity that is nents to enter the dome without requiring simultaneously posed a limitation in the used to test the accuracy of the polished the opening of the observing doors, performance of the telescope under surface. For the 42-metre design with was not necessary, and, furthermore, it heavy wind loading. Specifically, the sec- 6-metre secondary mirror, two matrix added complexity in the concrete pier ondary mirror deflections in the wind units would have been necessary. The of the dome. It has been removed from dominated the error budget for the new 4.2-metre mirror radius is within the the plans. The dome for the 42-metre 42-metre design and a feed-forward con- reach of a single such matrix, thereby telescope design had included a require- trol scheme for the tip-tilt M5 mirror, potentially greatly simplifying the polish- ment for a lifting platform that allowed based on accelerometer input from the ing metrology and the risk of mismatched access to the Nasmyth platforms and secondary, might have been necessary references. also to the secondary mirror. The plat- to meet the performance goals in the form was required to lift 30 tonnes to most stringent of environmental condi- Speeding up the focal ratio of the primary 30 metres above the floor in order to tions. However, given the need to reduce mirror and reducing the dimensions of support the exchange of the secondary costs and risks, reducing the size of the the secondary, also reduced the length of mirror with its cell. While engineering secondary mirror, beyond what a simple the telescope, which reduced the overall solutions existed and the concept was scaling would imply, provided a useful weight and made it easier to achieve the elegant, alternate cheaper solutions focus for the re-baselining activities. required stiffness. The provision of the based on cranes can be found to enable gravity-invariant focus under the Nasmyth the necessary manipulations. Removing In manufacturing large optical elements platform had proved to be a design driver the platform has made it possible to con- there exists a natural break-point at for the mechanical structure of the tele- figure the geometry of the telescope spi- diameters of around 4.2 metres that scope, requiring significant amounts of der that supports the secondary mirror arises from a series of trade-offs that steel reinforcement to provide the neces- so that it better reflects the direction of involve manufacturing facilities and sary stiffness for the instrumentation the loads generated as the telescope is dimensions of machines and processes. and the pre-focal station. Moreover, it inclined. We therefore placed a 4.2-metre diame- complicated the support and load trans- ter constraint on the secondary mirror fer to the azimuth tracks. By removing In addition to the aforementioned and evolved the optical design of the the gravity-invariant focus, speeding up changes to the Nasmyth platforms, the 39-metre E-ELT about that solution. We the primary and reducing the dimensions shorter telescope made it possible to

4 The Messenger 148 – June 2012 Figure 1. The segment test assembly in Garching. Figure 2. The seismic isolation test bed. Both the lat- Four fully polished segments have been mounted on eral and the vertical components of the earthquake their supports. Edge sensors and actuators have acceleration are significantly diminished through this been deployed on a number of the segments and isolation device. control testing has started. replace the carbon fibre in the spider with high bandwidth) prototype units under phase B design contractor in collabora- normal steel. This change removed one construction. In the area of edge sensors tion with providers of seismic isolation of the risks identified in the 42-metre the project has worked together with systems. During 2011 a scaled prototype design, and made it easier to balance the the suppliers to revise specifications and system was built and tested on a large telescope. modify various requirements based on shake system (see Figure 2). more detailed analysis of the results and In the area of opto-mechanics a number the requirements. The wind tunnel testing of the dome and of activities continued throughout the telescope main structure undertaken dur- delta phase B period. The secondary ing the phase B were extended in the mirror unit contract, which was still run- Prototype testing delta phase B to include the topography ning at the start of the delta phase B, of the Cerro Armazones site. The wind was extended in time to cover the period During phase B and the delta phase B tunnel results have been crucial in provid- of the new design. The prototyping of the project placed great emphasis on ing an alternate view to the computational the polishing of the primary mirror seg- prototypes that demonstrated the practi- fluid dynamics (CFD) analysis that is ments is progressing on multiple fronts. cal feasibility of the designs and plans. undertaken both in-house at ESO and by One supplier has delivered to ESO seg- The underlying principle was not only to our contractors. Figure 3a shows the ments that meet the specification for test the design but also to familiarise model used in the wind tunnel and Figure the most difficult to polish components of ESO and our industrial partners with the 3b a CFD simulation of the wind flow the primary mirror (see Figure 1). The difficulties and challenges ahead. through the dome. technical feasibility of the primary mirror, we feel, is now without doubt. The pro- The E-ELT design employs seismic isola- For the primary mirror, prototype systems ject has continued to invest funds and tion systems to reduce the effects of have been delivered to ESO from two manpower in following up different tech- ground accelerations on the dome and suppliers of primary mirror supports nologies for polishing with two additional the main structure. Such systems are (including warping harnesses, extractors, suppliers: using, in one case, stress mir- in common use in regions of high seismic packing and transporting systems, etc). ror techniques (as used for the Keck tele- risk but are usually made to isolate in Separate suppliers also delivered two scopes) and, in another case, a single, the horizontal direction only. While for the sets of position actuators and a set of fully robotic, process. The stress mirror dome this isolation would be sufficient, edge sensors. As mentioned above, a polishing has provided ESO with addi- we have considered that for the telescope number of segments have also been tional prototype segments and a strong pier seismic isolation should include manufactured. For the quaternary mirror, interest from industrial partners to en- a vertical component. The challenge has prototype systems have been manufac- gage with the project. been to provide the necessary isolation tured for representative subassemblies of without reducing the stiffness of the tele- the mirrors, including polished deforma- Progress was also made in the area of scope in normal operations. The neces- ble mirrors, electronics, actuators, etc. A actuators with further soft (low stiffness, sary system was designed by the dome complete electro-mechanical, scale one,

The Messenger 148 – June 2012 5 Telescopes and Instrumentation McPherson A. et al., Recent Progress towards the E-ELT

concepts was deployed at the Very Large Telescope (VLT) Unit Telescope 1 (UT1) dome at Paranal and is today used in operations by the observatory. The E-ELT technologies have been selected to prevent unmanageable obsolescence.

Almost all the hardware prototypes have been assembled in the E-ELT test Figure 3. Figure 3a (left) shows a 1:200 scale model facility located within the ESO warehouse of the E-ELT in its dome used in the wind tunnel test- facility in Garching Hochbrück. A stand ing. Figure 3b (right) shows the modelled wind flow that replicates the mirror cell structure though the dome. has been built and four of the prototype segments have been mounted, complete Figure 4. The electro- with their support structures, actuators mechanical M5 proto- and edge sensors (Figure 1). The system type. In the centre is a dummy mirror that is has been tuned and the loop between moved in tip-tilt by three the edge sensors and the actuators has heavy-duty actuators been closed. The tests in Hochbrück mounted behind the include field tests of the control architec- system. The covers being installed by Pablo ture and deployments of publish/sub- Barriga and Marin scribe components interfacing with COTS Dimmler give the full systems. dimensions of the M5 mirror as it will be installed in the tele- We continue to test phasing and control scope. methodologies in technical time awarded at the 10.4-metre Gran Telescopio Canarias (GTC). This work has been extremely beneficial to our understanding of how segmented mirror telescopes are controlled and the co-operation between the GTC and the E-ELT project teams has been excellent.

New wavefront sensor detectors based on complementary metal-oxide semicon- ductor (CMOS) technology are under development for the E-ELT project. The prototype pixels were successful and we expect our first 600 by 600 pixel fast readout, low readout noise detector in the coming months. unit has been manufactured for the tip-tilt B industrial suppliers provided solutions M5 mirror (see Figure 4). for the telescope Real-Time Computer The E-ELT project has contracted for the (RTC) needs. In particular a personal development of Vertical-External Cav- A scale one interlock system for the tele- computer based RTC for adaptive optics ity Surface-Emitting Lasers (VECSELs). scope and dome has been prototyped was shown to be feasible and a scale These development contracts have based on safety programmable logic cir- one RTC for the telescope control is in resulted in prototype systems that cuits (PLCs). The timing system based construction. are promising. In the context of the VLT on the IEEE 1588 standard has been Adaptive Optics Facility (AOF; see demonstrated. This is a critical technol- The control concepts for the E-ELT move Arsenault et al., 2011), there is much ogy for the project as it avoids creating away from the monolithic integrated ongoing work within ESO and contractors dedicated electronics and networks and approach of the past, and rely on Com- for lasers and laser launch telescopes. can rely on commercial switches and ponent Off The Shelf (COTS) principles The E-ELT project is following this work networks, such as Ethernet, for the distri- with which industry is familiar. This closely as the requirements for the AOF bution of timing signals. Electronic proto- approach reduces the interface risk with and the E-ELT are very similar and the type units have been constructed as industry. A number of these concepts AOF fibre lasers form the baseline today demonstrators for the secondary mirror have, or are being, proved in the field. In for the telescope. unit control and other units. During phase particular a prototype test of the E-ELT

6 The Messenger 148 – June 2012 Figure 5. An impression of the E-ELT in its enclosure at Cerro Armazones.

Infrastructure focusing of seismic waves by the particu- operating in the near-infrared, fed by lar geometry of the peak. adaptive optics; an integral field spectro- The Chilean government has agreed graph with a variety of plate scales that ESO can incorporate the Cerro Positive news is also available on the ranging from the diffraction limit to seeing Armazones site in the Paranal Observa- power generation front with activities limited, fed by adaptive optics. The tory 5. This has been an important mile- undertaken by the ESO engineering third instrument to be included in the stone for the E-ELT programme as the directorate, the ESO representation in construction project is a thermal infrared telescope is to be operated as an inte- Chile and the Chilean authorities to sup- instrument. For this instrument, a tech- gral part of Paranal. The operational port the connection of Paranal to the nology demonstration of the detector scenario presented in the construction Chilean national grid. is planned within the upgrade of the proposal foresees that the day crew VISIR instrument at Paranal. Additional commutes from the Paranal base camp instruments are budgeted for and planned to Armazones thereby minimising the Instrumentation within the E-ELT programme and selec- cost of additional facilities. A night crew tions will be made in due time. will be resident on Cerro Armazones, but The instrumentation activities have the control room is expected to be co- resulted in conceptual designs for a num- The interfaces to the observatory are located with those of the UTs on Paranal. ber of instruments covering a broad under development within the ESO range of capabilities (see D’Odorico & Instrumentation Division with support To this purpose the design of the road Ramsay, 2010). The instrumentation road from the Directorate of Engineering. linking the Armazones site with the map has been endorsed by the ESO Paranal road has had a high priority and Science and Technical Committee (STC) is well underway. The more extended geo- and presented as part of the construction Costing review and methodology technical survey of the Cerro Armazones proposal to the ESO Council. peak revealed no surprises. Additional Analysis of costing methodologies in seismic testing is underway to character- The two first light instruments have been scientific projects, and in industry at ise the amplification factor created by the selected: a diffraction-limited imager large, showed that uncertainty in the

The Messenger 148 – June 2012 7 Telescopes and Instrumentation McPherson A. et al., Recent Progress towards the E-ELT

design and lack of understanding of the awarded to more than one supplier, References risks increase the costs of projects providing not only a competition in cost Arsenault, R. et al. 2011, The Messenger, 142, 12 between the cost-estimation phase and and design, but also two independent D’Odorico, S. et al. 2010, The Messenger, 140, 17 award of contract. With this in view, assessments of the ESO requirements. Gilmozzi, R. & Kissler-Patig, M. 2010, and with the aim of minimising this risk, The Messenger, 143, 25 the E-ELT has pioneered (at least in Three formal reviews of the project were Spyromilio, J. et al. 2008, The Messenger, 133, 2 the field of astronomy) the concept of undertaken. The first technical and man- using competitive Front End Engineering agerial review of the complete phase B Links Design (FEED) studies as the design package took place in late 2010. A cost 1 vehicle before construction starts. These review took place in late 2011. Both E-ELT Construction Proposal: http://www.eso.org/ public.archives/books/pdf/e-elt_constrproposal. FEED contracts are awarded competi- review boards were comprised of experts pdf tively, typically to more than one supplier, drawn from the construction and man- 2 E-ELT Board report: http://www.eso.org/sci/facili- and provide not only a detailed design, agement of large scientific infrastructures. ties/eelt/docs/E-ELT-PhaseB-BoardReport_Exec- but also a firm, fixed-priced offer for con- A further cost, risk and management Summary.pdf 3 E-ELT Design Reference Mission: http://www.eso. struction. Where feasible, the FEED con- review was undertaken in late 2011 by an org/sci/facilities/eelt/science/doc/drm_report.pdf tracts were combined with prototype industrial firm specialising in such mat- 4 E-ELT Design Reference Science Cases: http:// construction at a limited scale. ters. All reviews gave the E-ELT project www.eso.org/sci/facilities/eelt/science/eelt/drm/ very good reports and useful feedback. cases.html 5 Agreement signed between Chilean government By adopting this practice, the design and ESO for Cerro Armazones site: http://www. process is not only competitive in the eso.org/public/news/eso1139/ area of performance, but also in the area Prospects of cost. Moreover, the process provides detailed visibility of the structure and The E-ELT project has matured from the nature of the cost of design choices. It is end of phase B in 2010 and is prepared certain that we have not retired cost risk for a start of construction as soon as the from the project, but we consider that ESO Council gives the go-ahead. we better understand our cost risks. FEED offers underpin the construction proposal for the E-ELT. Acknowledgements

The authors thank all the participants and participating institutes in the instrumentation studies (see arti- Managerial cles in The Messenger, 140, p. 17–39) and the advi- sory bodies and review committees that have guided The project management structure has the project so far. While the credit belongs to the many contributors to this work, the authors take also evolved in preparation for construc- responsibility for all errors. tion. Council has appointed the project manager (Alistair McPherson; see profile Much of the work described was undertaken under on p. 53) to lead the construction effort contract from ESO by industrial firms, amongst whom were: Active Space (Portugal); ADS (Italy); and the post of project engineer has AMOS (Belgium); ARUP (UK); ASDEA (Italy); BCD been advertised; by the time this article is (Italy); Boostec (France); Bronto Skylift (Finland); in print it is expected to have been filled. CESA (Spain); CILAS (France); CIRA (Italy); Corning (USA); Critical Software (Portugal); CSEM (Switzer- land); Demont (Italy); DSL (Canada); e2v (UK); EAI The work breakdown structure and prod- (Spain); EIE (Italy); Fogale (France); Franklin & uct trees have been updated and syn- Andrews (UK); IDOM (Spain); INES (Switzerland); chronised with the budget for the con- ISQ (Portugal); ITT (USA); Kirkholm (Denmark); KN struction. Technical reviews of the work Systemes (France); L3Com Brashear (USA); L3Com Tinsley (USA); Laboratoire D’Astrophysique Marseille undertaken by our contractors have (France); MicroEpsilon (Germany); Microgate (Italy); taken place during the design process. Micromega Dynamics (Belgium); MTMechatronics The E-ELT has contracted expert exter- (Germany); National Instruments (USA); NTE/SENER nal firms to assist the reviews of very (Spain); Observatory Sciences Ltd (UK); Optic Glyndwr (UK); ORC (Finland); Physik Instrumente large subsystems (e.g., the dome and (Germany); Rovsing (Denmark); Sagem (France); main structure). Additionally the E-ELT Sarnoff (USA); Schott (Germany); SciSys (UK); SESO has used external companies to verify (France); Siemens (Germany); SIRVE (Chile); Solving and critique the requirements of the pro- (Finland); Space Systems Finland (Finland); Threon (Germany); TNO (the Netherlands); UKATC (UK); ject, with a view to manufacturability and University of Liege (Belgium); USB (Germany); cost, as well as performance. As often as Weatherpark (Austria). possible, the contracted work has been

8 The Messenger 148 – June 2012 Telescopes and Instrumentation

Monitoring Atmospheric Water Vapour over Paranal to Optimise VISIR Science Operations

Florian Kerber1 direct support of service mode observa- will be able to accurately measure all reg- Thomas Rose 2 tions with the upgraded VISIR. ular humidity conditions over Paranal. Mario van den Ancker1 LHATPRO has an all-sky pointing capa- Richard R. Querel 3 The requirements for the monitor were bility and can scan the whole sky within on behalf of the Project Team* guided by the lessons learned during the a few minutes. work to characterise potential sites for the E-ELT in 2009 (Kerber et al., 2010a, b; 1 ESO Querel et al., 2010). The requirements Radiometer performance validation 2 Radiometer Physics GmbH, called for a high-precision, high time- Meckenheim, Germany resolution stand-alone PWV monitor that The radiometer underwent a qualification 3 Universidad de Chile, Santiago, Chile provides water vapour information in and acceptance test at the Umwelt- (near-) real time. While several ways exist forschungsstation (UFS) Schneeferner- to measure PWV, it quickly became clear haus2 located a little below the summit A water vapour radiometer has been that a dedicated radiometer operating of the Zugspitze (Figures 1a, b), the high- permanently deployed on Paranal as a at 183 GHz would be the most suitable est mountain peak in Germany. During new tool for supporting science opera- technical solution. An open call for tender a two-week period in September 2011 tions at the Very Large Telescope. resulted in the selection of the Low the instrument’s functionality and opera- The instrument allows the water vapour Humidity Atmospheric PROfiling radiome- tions were rigorously tested with respect content of the atmosphere above the ter (LHATPRO) produced by Radiometer to the original requirements and techni- observatory to be monitored in real time Physics GmbH (RPG). cal specifications. The UFS Schneefern- with high precision and time resolution erhaus site was chosen for a number and periods of low precipitable water The instrument probes the atmosphere of reasons: low PWV values can be vapour (PWV) to be selected, providing in two frequency ranges, focusing on two expected in central Europe during sum- better atmospheric transmission for prominent emission features: an H20 line mer/autumn only at high elevations; observations in the infrared. The PWV (183 GHz) and an O2 band (51–58 GHz). the altitude of Schneefernerhaus (2650 measurements will be made available to Using six and seven filters to sample the metres) almost exactly matches the VISIR users in the form of FITS header two bands, respectively, the radiometer final destination of the unit, the telescope keywords. In addition, we expect that retrieves the profile of humidity and tem- platform on Paranal (2635 metres). In over time these data will allow a deeper perature up to an altitude of about 12 kilo- addition, the UFS hosts a number of insight into the atmospheric condi- metres (Rose et al., 2005). The radiome- instruments measuring properties of the tions on Paranal, with implications also ter is designed and built for continuous atmosphere, including a water vapour for the operation of the European operations without human interaction and radiometer operating at 22 GHz and a Extremely Large Telescope (E-ELT) on can also be fully controlled remotely. In light detection and ranging (LIDAR) instru- nearby Cerro Armazones. terms of environmental conditions it is ment, allowing for parallel observations qualified for the temperature range –50 to between these instruments and the new +45 °C and an air blower and heater sys- PWV monitor. The VISIR upgrade and water vapour tem protects the instrument in extreme humidity and temperature conditions. After successful completion of the provi- The upgrade1 of the Very Large Tele- sional acceptance, the radiometer was scope (VLT) Imager and Spectrometer for The primary interest for VISIR is the inte- shipped to Chile and commissioning on the mid-infrared instrument (VISIR) is grated water vapour column that repre- Paranal took place during late October/ a project that combines improvements in sents the amount of water which would early November 2011 (see Figure 2). hardware, software and operations. As result from condensing the vertical at- part of the latter operations programme, mospheric column, expressed in milli The commissioning of the RPG LHATPRO a water vapour radiometer was deployed metres. The water vapour line near was closely modelled after the highly on Paranal in October 2011. The infor 183 GHz is intrinsically very strong and successful PWV campaigns conducted mation provided by this monitor of pre- still prominent at very low humidity levels, in 2009 as part of E-ELT site charac cipitable water vapour in the atmosphere thus making it suitable for monitoring terisation. Through technical time we had above the observatory will be used for a dry site such as Paranal. Paranal has a access to several VLT instruments: median PWV of 2.5 mm, but with pro- CRIRES, UVES, X-shooter, and of course nounced seasonal and short term varia- VISIR. For these optical and infrared (IR) *The commissioning team consists of: tions (Kerber et al., 2010a). The PWV val- instruments, PWV is extracted from 1 2 2 Florian Kerber , Thomas Rose , Harald Czekala , ues encountered during any year range absorption or emission line spectra using Richard R. Querel 3, Reinhard W. Hanuschik1, Julio Navarette1, Arlette Chacón4, Omar Cuevas4, from nearly zero to more than 15 mm. an atmospheric model. An accuracy of Michel Cure4, David A. Naylor 5, Gregory Tompkins 5, Early results from the first few months of about 15–20% had been demonstrated Guillermo Valdes1. operations demonstrate that the radiom- during the 2009 campaigns (Kerber et al., 1 2 3 ESO; Radiometer Physics GmbH; Universidad eter starts to saturate at 20 mm — well 2010a) with this approach and full details de Chile; 4 Grupo Astrometeorología, Universidad de Valparaíso, Chile; 5 Institute for Space Imaging beyond the original requirements (5 mm, of the spectral fitting procedure are given Science (ISIS), Lethbridge, Canada. with a goal of 10 mm), and hence it in Querel et al. (2011). In addition we

The Messenger 148 – June 2012 9 Telescopes and Instrumentation Kerber F. et al., Monitoring Atmospheric Water Vapour over Paranal

Figure 1a. On 19 Sep- operated an infrared radiometer built tember 2011 almost by the University of Lethbridge (Canada) half a metre of snow had to be cleared on the and provided on loan from the Giant terrace of the UFS Magellan Telescope (GMT). Finally, we Schneefernerhaus had a total of 22 radiosonde launches before the LHATPRO conducted by the astrometeorology radiometer could be set up for its test period in group at the Universidad de Valparaiso, Europe. Chile, again following the template of the 2009 PWV campaigns (Chacon et al., 2010).

A radiosonde consists of a very compact meteorological instrument package tethered to a helium-filled balloon. On launch it provides in situ measurements of the atmosphere along its ascent tra jectory to an altitude of about 25 kilo Figure 1b. Later during metres where the balloon bursts. Since the test period very the balloon is a passive device, the tra- good conditions with low water vapour were jectory is the result of the lift provided by prevalent. Note that the helium and the action of the local the UFS Schneefermer- wind. The sensors of the radiosonde pro- haus and Paranal are vide high time-resolution profiles of almost exactly at the same altitude of about temperature and dew point (humidity) 2650 metres above sea over the course of about 90 minutes after level. launch and such a dataset is the ac cepted standard in atmospheric and climate research.

Observations with the VLT instruments were strategically scheduled to allow for parallel observations during the radiosonde launches while LHATPRO would operate continuously (and the Canadian IRMA operated during the night). The resulting time series is shown in Figure 3. The variation in PWV was very pronounced over the two-week commissioning period, but agreement between LHATPRO and the radiosondes is excellent (at the 1% level) across the whole PWV range. Based on an absolute calibration using liquid nitrogen and comparison with the radiosondes, an accuracy of about 0.1 mm has been demonstrated for the PWV radiometer with an internal precision of 30 μm. This ensures that reliable readings can be obtained in the dri- est of conditions encountered on Paranal, which of course are the most valuable periods for IR astronomy.

Figure 2. Members of the commissioning team next to the water vapour radiometer at its final location at the eastern end of the platform behind Unit Tele- scope 4 (from left to right: Omar Cuevas, Richard Querel, Greg Tompkins, Florian Kerber, Thomas Rose, Reinhard Hanuschik, Arlette Chacón, Julio Navarette; Mario van den Ancker is missing from this picture following a night of science support).

10 The Messenger 148 – June 2012 Figure 3. Time series of the water vapour measurements by various instruments during commissioning (19 October – 4 November 2011). Excellent agreement is found between the RPG radiometer (dark blue points) and the radiosondes (black diamonds). Very high PWV values were recorded during an unusual weather pattern that trapped humidity at lower elevations. Note that this water vapour is not recognised by the GOES remote sensing satellite.

LL 5 /6

early warning for incoming fronts (see Figure 4 for a view of the display from LHATPRO). An IR radiometer is also part of the LHATPRO instrument package providing measurements of the brightness temperature of the sky down to –100 °C. Thus this specific model makes it possi- 3HLD,)# ble to detect not only water-bearing clouds, which are considerably warmer, (1, "1(1$2 5(2(1 &.$2 651>1/& 45$2 72' 1@CHNRNMC@R but also cold, high altitude clouds.

Clouds are rare on Paranal, but the most common form is high altitude cirrus con- Figure 4. Operational sisting only of ice crystals. Such clouds display of the water can be reliably detected as an increase vapour radiometer as available on Paranal. In in the sky brightness temperature of a the upper row all-sky few to a few tens of degrees with respect scans of PWV, liquid to a clear sky, which can be as cold as water and IR sky bright- –95 °C on Paranal. This operating mode ness temperature taken every six hours are dis- is still being tested and needs to be cali- played (from left to right) brated in terms of the extinction result- which can reveal high ing from the clouds and hence the im- cirrus clouds. In the pact on photometry. Nevertheless, the bottom row Hovmoeller plots of the same param- IR channel is perfectly capable of detect- eters show a 24-hour ing extremely thin cirrus and promises time series of a cone to become a useful operational tool in the scan (elevation 30 de- future. This information is already being grees) taken every 15 minutes. routinely used by the Paranal weather officer to assess the quality of a given night.

The PWV and IR sky brightness tem perature are available in real time as part of the automated site monitor information in the control room. Thus periods of low PWV can be readily identified by the Radiometer operations Currently, the radiometer measures PWV astronomers on duty. For service mode in zenith for most of a 24-hour period observations, real-time decisions can As a result of the commissioning, the interrupted by an all-sky scan (duration be made to select the most suitable PWV radiometer went into trial operations, about 7 minutes) every 6 hours. In addi- observing programmes for the current demonstrating excellent performance tion a cone scan (360 degrees in azi- atmospheric conditions, thereby match- and high reliability under all conditions muth) at an elevation of 30 degrees is ing the constraints provided by the Prin encountered. Failure of one component performed every 15 minutes. From these cipal Investigators. All data taken by rendered the temperature profiling unusa- data a Hovmoeller diagram is created the radiometer are also archived and will ble for a period, while the down time for showing the conditions at any given time be made available for more specialised the water vapour channel is below 2%. over the past 24 hours and serving as an use on request.

The Messenger 148 – June 2012 11 Telescopes and Instrumentation Kerber F. et al., Monitoring Atmospheric Water Vapour over Paranal

Paranal PWV across the year Figure 5. PWV conditions over Paranal based on the 7.0 analysis of about a decade of UVES data (Kerber et al., 2010a). A pronounced seasonal variation is evident, but very low PWV (< 1.5 mm) conditions are 6.0 available at the 25% level for most of the year.

75% quartile 50% quartile 5.0 25% quartile

4.0 m) V (m

PW 3.0

2.0

1.0

0.0 –15 15 45 75 105135 165195 225255 285315 345375 Day of year

Support of science operations the operation of VISIR will also allow the new insights to be derived into the atmos- scheduling of a limited number of service pheric conditions over the ESO sites in Water vapour is one of the main sources mode observations under particularly dry northern Chile and we expect that such of opacity in the Earth’s atmosphere (PWV < 1 mm) conditions, allowing the knowledge will prove useful for science in the thermal IR, the operating range of detection of fainter targets in the Q-band, operations of the VLT, and later the VISIR. Moreover, the PWV content of the or enabling particularly demanding ob- E-ELT. atmosphere above Paranal is strongly servations, such as the detection of water variable, both on short timescales, and in discs. The upgraded VISIR instrument with pronounced seasonal variations (see will become available to the ESO commu- Acknowledgements Figure 5). However, not all IR observa- nity from October 2012. The instrument The commissioning team is grateful to Paranal staff 3 tions are equally affected by the PWV web page as well as the user manuals for their excellent support during the commissioning conditions: whereas imaging and spec- will be updated with information concern- and early operations. We particularly thank Paranal troscopy in the Q-band atmospheric win- ing PWV to assist users in their proposal Science Operations for enabling flexible scheduling dow from 17–21 μm will strongly bene- preparation. of technical time which was crucial to obtain parallel observations with VLT instruments during the radio- fit from being performed under conditions sonde launches. It is a pleasure to thank the staff at of relatively low water vapour, imaging in the UFS Schneefernerhaus for their assistance dur- most wavelength regions of the N-band Outlook ing the test campaign in Europe. window (9–12 μm) would be less sensitive to PWV content. The LHATPRO radiometer has demon- References strated the ability to measure the PWV The introduction of the new PWV monitor above Paranal with high precision and Chacon, A. et al. 2010, SPIE, 7733, 77334K on Paranal offers a clear opportunity to accuracy and provide real-time informa- Kerber, F. et al. 2010a, SPIE, 7733, 7731M Kerber, F. et al. 2010b, The Messenger, 141, 9 optimise the scientific return of infrared tion for support of science operations. Rose, T. et al. 2005, Atmospheric Research, 75, 183 instruments like VISIR by matching the For the first time, atmospheric PWV is Querel, R. R. et al. 2010, SPIE, 7733, 773349 PWV needs of each observation carried now routinely monitored and brought into Querel, R. R., Naylor, D. A. & Kerber, F. 2011, PASP, out in service mode to the actual condi- use for selecting the most suitable astro- 123, 222 tions measured in real time by the PWV nomical observations for the prevailing monitor. Hence PWV will be introduced conditions. The PWV conditions during Links as a formal observing constraint, analo- the time of observation will be docu- 1 gous to seeing or sky transparency in the mented for the user in the VISIR science VISIR upgrade project webpage: http://www.eso. org/sci/facilities/paranal/instruments/visir/ optical, for VISIR observations from ESO headers. Since the PWV data are also upgradeproject.html Period 90 onwards (October 2012). Apart archived, a set of temperature and 2 Umweltforschungsstation Schneefernerhaus: from allowing the observatory to better humidity profiles, which provide a means http://www.schneefernerhaus.de 3 match the needs of each observation to of characterising the properties of the VISIR web page: http://www.eso.org/sci/facilities/ paranal/instruments/visir/overview.html the actual atmospheric conditions at the atmosphere, will be built up over time. time of observation, this new feature of We anticipate that this dataset will enable

12 The Messenger 148 – June 2012 Telescopes and Instrumentation

PILMOS: Pre-Image-Less Multi-Object Spectroscopy for VIMOS

Paul Bristow1 In practice, when VIMOS started to spectrograph optics, so we can effec- Pedro Baksai1 be used in operations, it was decided tively subtract this from Sky2CCD leaving Italo Balestra 2 that pre-imaging should be mandatory just the sky-to-mask transformation.) Hans Dekker1 to ensure that uncertainties in the map- Cesar Enrique Garcia Dabo1 ping of celestial coordinates to detector Astrometric calibration exposures were Peter Hammersley1 coordinates did not lead to incorrectly part of the original VIMOS calibration Carlo Izzo1* placed slits. This requirement had the ef plan, but they became essentially redun- Steffen Mieske1 fect of increasing the total telescope time dant when pre-images were made man- Marina Rejkuba1 required to obtain a typical MOS expo- datory and were subsequently neglected. Piero Rosati1 sure by up to about 15% (Hammersley et Since the start of this project, astrometric Ruben Sanchez-Janssen1 al., 2010). Moreover, pre-images are typi- calibration has been monitored on a Fernando Selman1 cally obtained several weeks to a month monthly basis. Burkhard Wolff 1 prior to the MOS observations, but sometimes much older pre-images are used As part of the PILMOS project, the astro- to prepare the MOS masks and the fol- metric catalogues used by VIMOS were 1 ESO low-up MOS observation blocks (OBs). refined by filtering out stars with large 2 INAF–Osservatorio Astronomico di errors in their positions and correcting for Trieste, Italy Ironically, the very fact that the pre- proper motions. The accuracy of the * Deceased imaging procedure adopted for VIMOS calibration of Sky2CCD is in fact limited worked, and the fact that pre-images by the form of the fit and the sparse sam- as old as one or two years produced reli- pling of the field of view (FoV), even for The primary observing mode of the able MOS masks, was a good indica- relatively dense astrometric fields, rather VLT visible imager and multi-object/ tion that the transformation from the sky than by any systematic effects (such as integral field spectrometer, VIMOS, is to the mask plane was stable and could flexure, thermal expansion, atmospheric multi-object spectroscopy, for which be calibrated in such a way to allow pre- dispersion, aging, etc; see below). Despite pre-imaging with VIMOS is currently image-less MOS observations (hereafter this limitation, the Sky2CCD calibration mandatory. We report on the results of PILMOS). Therefore a detailed investiga- is still good enough to ensure that targets a study of the astrometric calibration tion of issues that can affect the reliability are not lost from the slits when per- of the VIMOS imaging mode and the of PILMOS masks was undertaken to formed properly. efforts to improve it. Based on this ensure that the consequent saving in pre- study, we announce the introduction of image exposure time would not be ac- Figure 1 is a histogram of the residuals an option that allows users to omit companied by large slit losses. Following between the predicted (using the Sky- the VIMOS pre-imaging step and create the positive conclusion of this investiga- 2CCD solution) and measured astromet- masks directly from sufficiently accu- tion, a procedure that enables users to ric star positions. The measured posi- rate astrometric catalogues. create PILMOS masks via the use of a tions are from several exposures of simple observation preparation tool was astrometric fields spread over several devised. This procedure has recently been months and that differ from those used to Introduction tested on realistic MOS observations. obtain the Sky2CCD transformations being tested. It is clear that towards the The VIMOS upgrade over the last couple edges, and especially the corners, of the of years has covered hardware (including Feasibility of pre-image-less mask detectors the fit is less reliable, but even detectors and prisms), software, main creation there the vast majority of stars will be tenance and operations (see Hammersley found within 2.5 pix (0.5 arcseconds) of et al., 2010; Hammersley et al. in prep.). In order to create PILMOS masks we where they are expected. Moreover, Here we concentrate on one operational need to be able to reliably map celestial vignetting by the intregral field units (IFUs) issue that has now been addressed, coordinates to locations in the VIMOS precludes the use of the very top and namely the option to create multi-object mask plane. In practice we cannot cali- bottom edges of the detectors (most of spectroscopy (MOS) masks without brate this mapping directly since we the red zone in Figure 1). the need to obtain pre-image exposures do not have a detector at the location of with VIMOS. the mask plane. However we can cali- Pinhole Mask2CCD calibration exposures brate the sky-to-detector transformation are essential for both the conventional The original concept for VIMOS foresaw (known as Sky2CCD) with exposures pre-imaging strategy and PILMOS. They the possibility of creating MOS masks of astrometric fields and then map the measure the distortions in the collimator directly from astrometric catalogues, but mask-to-detector transformation (Mask- and camera optics. Analysis of several the imaging capability was included to 2CCD) via calibration exposures of months of pinhole exposures obtained at provide accurate astrometry in cases pinhole masks. The sky-to-mask transfor- a fixed orientation (i.e., free of flexure as where no suitable catalogue was avail mation can then be derived from these the field is rotated) revealed the expected able and to aid users in placing custom two transformations. (Mask2CCD embod- thermal effects; once these were re slits (tilted or curved) on specific targets. ies the distortions resulting from the moved the Mask2CCD transformation

The Messenger 148 – June 2012 13 Telescopes and Instrumentation Bristow P. et al., Pre-Image-Less Multi-Object Spectroscopy for VIMOS

correlation step that would have re quired a pre-image. A guide to the use of this tool will be available in the forth- coming release of the VIMOS User Man- ual (see the VIMOS support pages2).

@BSHNM Trial results %Q

While investigating the feasibility of PILMOS, we gathered sufficient evidence to suggest that PILMOS would perform at least as well as pre-imaging in terms of minimising slit losses. Nevertheless, 1DRHCT@KOHW before offering the tool to observers we performed realistic end-to-end on-sky Figure 1. Histogram showing residuals between pre- Several other VIMOS upgrade activities tests in order to rule out any unexpected dicted and measured centroids for stars in astromet- (Hammersley et al., 2010) have helped problems in the PILMOS strategy. ric fields. The colours indicate samples of stars at different distances (r, in pixels) from the centre of to improve the positioning of slits. For the detectors as follows: green r < 300; black 300 < example: We used the PILMOS tool to prepare r < 600; blue 600 < r < 900; pink 900 < r < 1200; – Automatic flexure compensation (AFC): masks for three stellar fields at declina- red r > 1200. The inset indicates how these annuli Although AFC only improves the stabil- tions of 0, –25 and –60 degrees. Each map onto the imaging FoV of a VIMOS detector. Each histogram is normalised by the sample size. ity of VIMOS after the mask plane, it target had a 2 arcsecond wide slit so that has improved the stability of the Mask- it was possible to accurately measure 2CCD transformation and thus also the the centroids of the targets in the acquisi- derived sky-to-mask transformation; tion images. For comparison we obtained was constant to < 0.25 pixels across the – Mask insertion: Procedures for loading pre-images of the same fields and used FoV. In practice some residual flexure masks have been made more robust these to create masks with the conven- (not seen in the pinhole exposures, which and pinholes are now added to masks tional procedure. Analysis of the acquisi- were all obtained at a fixed orientation) is to allow their proper insertion to be tion images obtained with these masks to be expected even after the implemen- automatically verified. revealed small but systematic differences tation of the automatic flexure compensa- in the mean residuals (of the order of one tion system (described in Hammersley These activities will be described in pixel, 0.2 arcseconds) for the PILMOS et al., 2010). These same effects will be greater detail in Hammersley et al. in prep. and pre-image cases that varied from present in the astrometric calibrations quadrant to quadrant and to a lesser ex- as long as the astrometric and pinhole tent from field to field. However the scat- mask calibrations are obtained under The PILMOS tool ter in the residuals was very similar and similar conditions (epoch, temperature the overall performance in terms of the and orientation) and cancel out when the PILMOS mask preparation is done with fraction of targets that were within about resulting sky-to-mask transformation is a new (extended) version of the Guide- one pixel of the slit centres for each field derived. The ESO quality control pages1 cam application, with which VIMOS users did not differ significantly between the provide access to diagnostics from these are already familiar in selecting their FoV two methods, as summarised in Table 1. calibrations during VIMOS operations. and guide star. The new options in Guide- cam are the upload of the user-contrib- Another effect that may cause some uted catalogue and a button that initiates δ (º) Method |Δ y| > 1.0 pix. |Δ y| > 1.5 pix. changes in the sky-to-mask transforma- the generation, for all four quadrants, of: 0 PILMOS 18(10)/58 6(5)/58 tion for a given observation is the varia- – A simulated pre-image that includes the 0 Pre-image 4(3)/57 1(1)/57 tion of apparent relative positions of targets in the catalogue and the area –25 PILMOS 22(15)/50 9(9)/50 sources with air mass and parallactic vignetted by the guide probe as well as –25 Pre-image 21(16)/50 7(11)/50 angle caused by atmospheric dispersion a header containing all of the keywords –60 PILMOS 16(9)/41 7(4)/41 (see Cuby et al., 1998). The constraints and values that would have been in a –60 Pre-image 10(12)/33 10(8)/33 applied to VIMOS observations currently real pre-image; in place effectively ensure that the – A VIMOS catalogue with detector coor- Table 1. Scatter in residuals for pre-image and PILMOS object centroiding. The number of targets atmospheric dispersion present in pre- dinates matched to celestial coordi- having more than 1.0 and 1.5 pixel offsets in the images is very similar to that in MOS nates for each target. This intermediate three stellar test fields is listed in columns 3 and 4. observations. Hence, the hour-angle con- catalogue enables users to prepare The first figure in each column is the number directly straints for MOS exposures (see below) masks directly within VIMOS mask measured in the data, the number in brackets is the value that would be measured if the reference stars have been retained, at least for the initial preparation software (VMMPS) applica- had been optimally centred and the final number is phases of PILMOS. tion, thus skipping the first cross- the sample size.

14 The Messenger 148 – June 2012 Figure 2. Centring of sources relative to the slits in the PILMOS mask acquisition image (upper) and the pre-image mask acquisition image (lower) is shown. The colours indicate the quadrants as follows: Q1 = red; Q2 = blue; Q3 = green; Q4 = grey.

S firming that the PILMOS strategy can

NTM deliver equally valid results. In this case " PILMOS would have saved four minutes of pre-imaging for one hour of MOS follow-up, and once overheads are factored in, the saving is approximately 14 %.

l l l l l l l Introduction of PILMOS 2KHSBDMSQDl3@QFDSBDMSQDOHW From summer 2012 observers will be able to choose to omit pre-imaging and create their MOS masks directly from catalogues with the PILMOS tool. In order to do this they will need to obtain the latest version of the Guidecam tool from the ESO Phase 2 web pages3. In addi-

S tion the following restrictions will apply to NTM PILMOS observations: " – Slits should be at least 1 arcsecond

wide (this is currently the most typically used slit width for VIMOS observations); – Only straight slits aligned north–south are permitted (no waivers for rotator angle different from 90 degrees are l l l l l l l allowed for PILMOS); 2KHSBDMSQDl3@QFDSBDMSQDOHW – Fields should be obtained within two hours of the meridian (as is currently the case for pre-image based MOS As a further test, in collaboration with the less than half of a 1 arcsecond slit width, exposures); Cluster Lensing and Supernova Survey not all quadrants are well aligned, both – The contributed catalogue must have with Hubble (CLASH) VIMOS Large Pro- for PILMOS and pre-imaging acquisition relative astrometry better than 0.2 arc- gramme (described in Postman et al., images. Hence, in this test, performance seconds and absolute astrometry 2012), we used the PILMOS tool to create was non-optimal in at least one quadrant must be consistent with the Guide Star masks based on the same input cata- for both methods, but there is no indica- Catalogue to within 2 arcseconds; logue used to prepare one of the existing tion that the use of PILMOS significantly – The catalogues should contain at least MOS OBs that was part of their regular degrades performance relative to pre- two suitable reference stars per quad- programme (and thus prepared using imaging (here it is slightly better, but rant that are corrected for proper pre-imaging). All the other details were not at a level that is statistically signifi- motion and on the same astrometric identical. Figure 2 shows the centring of cant). Global offsets are easily corrected system as the other targets. targets in all four quadrants as deter- when centring the MOS stars in their mined from the acquisition images of the boxes during the acquisition exposures, We are continuing to monitor the stability conventional pre-image masks and the although offsets between quadrants can- of VIMOS distortions and the impact PILMOS masks. In deriving these results not be corrected in this way. of issues such as atmospheric dispersion we corrected for slit vignetting. Note that (Sanchez-Janssen et al.,in prep.) with about 40% of the targets were too faint Figure 3 shows two typical extracted a view to relaxing these restrictions in the to be identified in the short, undispersed spectra, each obtained with both the future. The conventional pre-imaging acquisition images and do not contribute PILMOS and pre-image masks, after pro- strategy is available for observers who to these statistics. cessing by the CLASH project team cannot meet these requirements. Pre- using their standard data reduction. In imaging will continue to be offered as the Figure 2 indicates that, bearing in mind general they found that the signal-to- main option, at least during the first the omission of the faintest targets, whilst noise in the pre-image and PILMOS period that this mode is offered, for the within any quadrant the offsets vary by derived spectra were very similar, con- reasons given in the introduction.

The Messenger 148 – June 2012 15 Telescopes and Instrumentation Bristow P. et al., Pre-Image-Less Multi-Object Spectroscopy for VIMOS

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Figure 3. Example VIMOS processed spectra are shown with pre-imaging and with PILMOS: (a) and (b) were obtained with the PILMOS masks; (c) and (d) are the same sources obtained with pre- image masks. Line identifications are also shown. Note that in (b) and (d) it is the lower spectrum that is extracted.

Acknowledgements Links

We wish to thank Luigi Guzzo and Bianca Garilli and 1 ESO quality control pages for VIMOS: http:// the VIPERS team for their cooperation. www.eso.org/observing/dfo/quality/VIMOS/qc/ mask2ccd_qc1.html 2 VIMOS support pages: http://www.eso.org/sci/ References observing/phase2/SMGuidelines/VMMPS.VIMOS. html Cuby, J. G., Bottini, D. & Picat, J. P. 1998, Proc. 3 VIMOS Service Mode guidelines: http://www.eso. SPIE, 3355, 36 org/sci/observing/phase2/SMGuidelines/Guide- Hammersley, P. et al. 2010, The Messenger, 142, 8 camVIMOS.html Postman, M. et al. 2012, ApJ, 199, 25

16 The Messenger 148 – June 2012 Telescopes and Instrumentation

A Method to Deal with the Fringe-like Pattern in VIMOS-IFU Data

Carina Lagerholm1 FoV into four quadrants, which are pro- most likely origin of the fringe-like patterns Harald Kuntschner1 cessed separately and combined into a is a “pseudo-etalon” — approximately Michele Cappellari 2 datacube as a final data reduction step. 3–10 μm thick — created by imperfect Davor Krajnovíc1 fixing of the fibre to the output prism Richard McDermid 3 For the data reduction the ESO pipeline (Hans Dekker, private communication; Marina Rejkuba1 can be used with the standard settings Lagerholm et al., 2012). The fringe-like given in the pipeline manual. After the patterns are present in the science data data reduction, the datacubes still fea- and in the flat field; they are also pre- 1 ESO ture some problems that need to be sent in the raw data, and thus cannot be 2 Sub-department of Astrophysics, attended to before any scientific analysis an artefact created by the data reduction University of Oxford, United Kingdom can begin. Firstly, there are large-scale process. 3 Gemini Observatory, Northern intensity differences between the four Operations Centre, Hawaii, USA quadrants and also differences between The fringe-like pattern affects more than individual spectra visible as stripes in half of the spectra in a VIMOS-IFU data the reconstructed image; the details of cube. The amplitude and frequency of Many observers using spectrographs which are described in Lagerholm et al. the fringe-like pattern is not randomly dis- will be familiar with the fringes nor- (2012). In this article, we will focus on the tributed between fibres but shows a mally appearing at longer wavelengths more severe problem of fringe-like fea- clear connection to specific fibre mod- (λ ≥ 7000 Å). In spectra obtained with tures visible in the spectral domain even ules. In quadrant 2 almost all spectra are the VIMOS integral field unit such a at optical wavelengths. affected, while the other quadrants ex fringe-like pattern is also observed in hibit regions with negligible or no fringe- the optical wavelength range. This like patterns (Figure 2). What is important fringe-like pattern affects the shape of The fringe-like pattern to note is that the fringe-like pattern the continuum and will, if not corrected, varies with time as indicated in Figure 1, have consequences for derived param- It has been known for several years (e.g., where we plot the fringe-like pattern eters such as recession velocity, stellar Jullo et al. 2008; VLT VIMOS manual) in the same spatial element separated in velocity dispersion and line strengths. that VIMOS-IFU spectra acquired with the time. An explanation for this can be the We describe an empirical method HR-Blue and HR-Orange grisms exhibit change in the instrument rotator angle to correct for these fringe-like patterns spectral features that are visually similar and associated flexure in the instrument, and briefly describe the improved to fringes. Fringes normally arise from the which changes the properties of the results. interference in the charge-coupled device pseudo-etalon. In the most affected (CCD) detection layer between the inci- spectra, the pattern accounts for around dent light and the light reflected from the 13% difference in intensity, peak-to-valley Integrated field units (IFUs) are now com- interfaces of the CCD layer. Due to the (PTV), while the mean value of the effect mon at all major observatories, where typical thickness of this layer, fringes are is about 6%. they offer an efficient means of obtaining observed at red wavelengths (> 7000 Å). spectra and imaging information at the The features seen in the VIMOS-IFU same time. Due to the complex design of spectra resemble fringes but are present The empirical correction method the IFU instruments and the large amount over the whole wavelength range (see of information, there are often challenges Figure 1), suggesting that they are We have devised an empirical method for the data reduction pipelines. In the caused by a different mechanism. The for removing the fringe-like patterns case of the VLT visible image and multi- object/integral field spectrometer (VIMOS), data from its IFU mode require additional Figure 1. The fringe-like reduction steps beyond the standard pattern in the VIMOS- IFU used with the HR pipeline in order to handle some issues Blue grism. Upper not resolved by the pipeline. The VIMOS- panel: Flat-field spectrum from a single spa- IFU contains 6400 microlenses coupled to fibres covering the wavelength range TW tial element (fibre) clearly

Ck showing the effects of 4000–10150 Å with a set of six grisms the fringe-like pattern (Le Fèvre et al., 2003). With the medium (black). Lower panel: the and high resolution grisms only a square corresponding, normal- -NQL@KHRD of 40 × 40 fibres is used, yielding either ised correction function for this fibre (black). In a field-of-view (FoV) of 27 by 27 arcsec- grey the flat-field spec- onds at 0.67 arcseconds per fibre or a trum and correction FoV of 13 by 13 arcseconds at 0.33 arc- function are shown from seconds per fibre. The light is fed to the same spatial element but observed on a four different spectrographs dividing the 6@UDKDMFSGÄ different night.

The Messenger 148 – June 2012 17 Telescopes and Instrumentation Lagerholm C. et al., A Method to Deal with the Fringe-like Pattern in VIMOS-IFU Data

Figure 2. Spatial map of from VIMOS-IFU data. Our method is the maximum variations constructed to work on data without (PTV) in the correction spectra is shown as strong intensity differences, such as derived from a flat-field early-type galaxies, which have a smooth and the wavelength surface brightness profile. The method range 5188–5620 Å. was developed and tested on HR-Blue Regions with a strong fringe-like pattern are grism data (coverage 4015 –6200 Å) with clearly visible and the 27 by 27 arcsecond FoV. K related to distinct fibre WD /35 /H modules. The white solid Our method is applied on individual, fully lines indicate the bor- ders of the quadrants. reduced datacubes. The underlying Quadrant 1 is located at assumption is that, to first order, the the top right, with quad- fringe-like patterns are localised, i.e. they rant numbers increasing are different between spectra that are counterclockwise. spatially neighbouring on the sky. This is a reasonable assumption if the fringe- like pattern is caused by a pseudo-etalon associated with the fibre output prism. /HWDK If all spectra have different fringe-like patterns, a median spectrum of eight spectra surrounding each spectrum (central spectrum) would be, to first order, R free from the fringe-like pattern. This

R median spectrum can be used as an M approximation of the underlying “true” JL

X spectrum, since the spectral properties RODQRHN H of our targets vary relatively slowly as a KNBHS

XC function of spatial position and the signal 5D in the spatially neighbouring spectra is KNBHS

5D correlated due to seeing. The ratio of the median spectrum to that of the central spectrum will provide an estimate of the /35 /35 fringe-like pattern, i.e. a correction spec- l trum that by construction has a mean of about one. l The correction spectrum is typically lim- l ited in signal-to-noise (S/N), and, since A

we are only interested in the overall a ' ,F l shape of the correction spectrum, we smooth the spectrum using the lowess l smoothing function within IDL, which is part of the IDL astronomy user’s library l (Landsman, 1993). Taking into account the typical frequency of the pattern, we /35 /35 smooth the correction spectrum using a second order polynomial for each step of 150 pixels. For each spectrum in the datacube, a smoothed correction spec- Figure 3. Simulations of the effects of the fringe-like trum is constructed, except in the outer-

pattern are shown. Changes in recession velocity, most corners and spectra neighbouring

velocity dispersion and the line strength indices more than three dead fibres. We remove Mg-b, H A and Fe 5270 are shown as function of D γ

% the fringe-like pattern from the datacube the amplitude (peak-to-valley, PTV) of the fringe-like pattern here approximated by a sinusoid. Different by dividing each spectrum by the corre- colours indicate different phase shifts of the sinu- sponding smoothed correction spectrum. soid, equally separated between 0 and 2 π. The shift The end product is a datacube corrected in colour goes from dark green, red, magenta, blue, for the fringe-like pattern. light blue, light green, back to dark green. The black dashed lines indicate the correct values given by the /35 fringe-free galaxy spectrum.

18 The Messenger 148 – June 2012 Science impact ments, we constructed simple simula- above numbers are representative for tions obtained from IFU data of nearby individual exposures and single fibres, the If the fringe-like pattern is not corrected, early-type galaxies. In these simulations combination of several dithered expo- it can adversely affect the science de we approximated the fringe-like pattern sures or fibres will significantly mitigate rived from the data. The fringe-like pattern with a sinusoidal function with varying the problem. changes the continuum level in the spec- phase and amplitude to illustrate how the tra and will thus affect, for example, differences will affect derived recession As mentioned earlier, our empirical line-strength measurements. In the Lick/ velocities, velocity dispersions and line method was constructed and tested on IDS system (Trager et al., 1998), ab strengths. In our simulations we changed data with slowly varying spectral proper- sorption line strengths are measured by the amplitude (PTV between 0% and ties. For other types of data, such as indices, where a central feature band- 15%) and phase (between 0 and 2 π). We with strongly varying background or low pass is flanked to the blue and red sides multiplied these different simulated intensities (the fringe-like pattern scales by pseudo-continuum bandpasses. The fringe-like patterns into a galaxy spec- with the intensity), a different approach mean level of the two pseudo-continuum trum free from the fringe-like pattern and should be preferred. In these cases it regions is determined independently measured the corresponding velocities, may be better to rely on the combination on each side of the feature bandpass and velocity dispersions and line strengths. of several exposures; we would recom- a straight line is drawn through the mid- The results are summarised in Figure 3. mend the combination of about eight point of each one. The difference in flux As expected, the exact location of the exposures thus mimicking the averaging between this line and the observed spec- fringe-like pattern determines whether a effect used in our method. trum within the feature bandpass deter- given quantity is changed in a positive mines the index. If the continuum level or negative direction. Even for large is changed due to the fringe-like pattern amplitudes, a negligible change is possi- References across the range of the blue and red ble when the effects of the fringe-like pat- Jullo, E. et al. 2008, in 2007 ESO Instrument bandpasses, the derived values for the tern cancel out. For a typical amplitude Calibration Workshop, eds. Kaufer, A. & Kerber, indices will be wrong. Furthermore, of 5% (PTV = 10), the velocity measure- F., 343 velocity and velocity dispersion measurement can be affected by up to ± 20 km/s, Lagerholm, C. et al. 2012, A&A, 541, 82 ments can also be affected, although the velocity dispersion up to ± 40 km/s, Landsman, W. 1993, in ASP Conf. 52, ADASS II, eds. Hanisch, R. J., Brissenden, R. J. V. & Barnes, to a lesser extent since these measure- the Mg-b line strength index by up to J., 246 ments are typically obtained from a larger ± 0.5 Å, the Hγ A index up to ± 1 Å, and Le Fèvre, O. et al. 2003, Proc. SPIE, 4841, 1670 wavelength range covering several peri- the Fe 5270 index up to ± 0.3 Å. We Trager, S. et al. 1998, ApJS, 116, 1 ods of the fringe-like pattern. therefore conclude that for these typical amplitudes of the fringe-like pattern, In order to evaluate the effects of the there is a significant influence on the sci- fringe-like pattern on typical measure- entific analysis. However, while these

A colour image of the grand design Sc spiral galaxy NGC 6118 taken with VIMOS. Three images in B-, V- and R-bands were combined and the image size is 6.5 by 5.2 arcminutes. NGC 6118 hosted a recent core collapse supernova of Type Ib, SN 2004dk. See Picture of the Week potw1022 for more details.

The Messenger 148 – June 2012 19 Astronomical Science See Release eso1220 for more details. 5.5 kpc. about of adistance at Halo Galactic the in cluster globular poor ametal- is M55 VISTA telescope. the the in images from formed (NGC 6809) Galactic globular cluster M55 the of composite A near-infrared Y - and H - and -bands taken with with taken -bands

ESO/J. Emerson/VISTA. Acknowledgement: Cambridge Astronomical Survey Unit Astronomical Science

The Chemistry and Magnetism of Young and Old Intermediate-mass Stars Observed with CRIRES

Swetlana Hubrig1 reveal compositions generally thought While many of the CP abundance pat- Charles R. Cowley 2 to be confined to the surface regions, terns may be explained by separation Fiorella Castelli 3 and not to the bulk of the stars. The processes in the stars themselves, there Jorge F. González 4 majority of one sub-group of the CP stars, is a class of CP stars where this does Burkhard Wolff 5 Ap/Bp stars, exhibit magnetic fields not seem to be the case. These stars are Vladimir G. Elkin 6 that belong to the stars as a whole and named after their prototype, l Bootis. Gautier Mathys 5 not just to star spots. Neither the origin The class represents only about 2% of Markus Schöller 5 of these magnetic fields nor the surface the population of A and B stars, to be chemistry of this sub-group is thoroughly compared with CP stars which may be as understood. many as 30% of all A and B stars. For 1 Leibniz-Institut für Astrophysik Potsdam the l Boo stars, the chemical separation (AIP), Germany For the Sun or solar-type stars, there are processes may have taken place outside 2 Department of Astronomy, University of good road maps for the near-infrared of the stars themselves – possibly in Michigan, Ann Arbor, USA (NIR) region of the spectrum covered by circumstellar or even interstellar material. 3 Istituto Nazionale di Astrofisica, the CRIRES spectrograph (c.f. Ryde et Osservatorio Astronomico di Trieste, al., 2010). The same cannot however be Italy said for A- and B-type stars, and in par- The progenitors of CP stars 4 Instituto de Ciencias Astronomicas, ticular for CP stars. We know from the de la Tierra, y del Espacio (ICATE), optical and ultraviolet (UV) spectra of CP What might these CP stars have looked San Juan, Argentina stars that they are replete with transitions like when they were very young? 5 ESO from exotic elements, as well as with high Recently, considerable effort has been 6 Jeremiah Horrocks Institute, University excitation transitions from overabundant given to investigations of young, pre-main of Central Lancashire, Preston, United elements. sequence stars known as Herbig Ae/Be Kingdom stars. These stars are considered as pro- Owing to the extreme richness of their UV genitors of main sequence stars of inter- and optical spectra, the upper main mediate mass. The Herbigs, as they are In contrast to the case for the late-type sequence CP stars have been intensively called, are often associated with gaseous stars, our knowledge of atomic transi studied at the highest possible spectral and dusty regions of our Galaxy, where tions in intermediate-mass chemically resolution over the last few decades. star formation is known to occur. The peculiar stars and in Herbig Ae/Be stars These stars present a natural laboratory letter e appended to their class denotes is still quite poor. This is especially true to study the element enrichment of stellar emission. The lowest Balmer lines, Ha in the infrared region of the spectrum. atmospheres due to the operation of and Hb, typically have emission stronger The recent availability of ESO’s high- various competing physical effects (such than the stellar continuum (see the exam- resolution spectrograph CRIRES now as, for example, microscopic diffusion ple in Figure 1), while higher Balmer lines offers the opportunity to study numer- of trace atomic species) in the presence may show emission in their absorption ous spectral features in the near-infra- of strong magnetic fields. Due to their cores. red spectra of these types of stars. generally slow rotation, it is also possible Example observations are presented to study the isotopic and hyperfine struc- If some fraction of Herbig Ae/Be stars are and the chemistry and magnetic field ture of certain elements and their interac- the progenitors of CP stars, we might properties are discussed. During these tion with the magnetic field. expect them to have measurable mag- studies a CO ring was detected around the Herbig Ae star HD 101412.

Upper main sequence stars with rich ultraviolet and optical spectra

Stars on the upper main sequence have TW a wide variety of chemical abundances. Ck They are often unrelated to the processes that contributed to the bulk composition of the Sun or the population of stars -NQL@KHRD with masses less than about 1.5 M . The A compositions of the lower-mass stars are Figure 1. Example Ha due to nuclear processes acting through- emission line profiles in out the history of the Galaxy, to form the two magnetic Herbig chemical elements other than hydrogen Ae stars HD 101412 (lower spectrum) and and helium. Spectra of upper main HD 190073 (upper sequence chemically peculiar (CP) stars 6@UDKDMFSGML spectrum) are shown.

The Messenger 148 – June 2012 21 Astronomical Science Hubrig S. et al., Young and Old Intermediate-mass Stars Observed with CRIRES

netic fields and some indication of chemi- log gf values for Si i by those from serve as a consistency check in the cal peculiarities. Additionally, the progeni Meléndez & Barbuy (1999). We added a cases where line identification is doubtful. tors of l Boo-type peculiar stars might few lines of Ce iii with wavelengths and When an external magnetic field is show some characteristic signature in log gf values computed by Biémont applied, spectral lines can split into sev- their circumstellar material. Recent spec- (private communication), and a Dy ii line at eral differently polarised π and σ com tropolarimetric observations of a few 1083.594 nm taken from the VALD data- ponents of slightly different wavelengths, Herbig Ae/Be stars have indicated that base (e.g., Heiter et al., 2008). The line- depending on the direction of the ob- magnetic fields are important ingredients broadening parameters are those com- server. In a longitudinal magnetic field, of the intermediate-mass star formation puted by Kurucz; they are available for the π components vanish and the σ com- process. As an example, the sharp-lined most of the identified lines, except for the ponents on opposite sides of the non- young Herbig Ae star HD 101412 with a Sr ii, Ce iii, and Dy ii lines, where they were magnetic line wavelength have opposite strong surface magnetic field of the order computed using classical approxima- circular polarisation. Synthetic line pro of a few kiloGauss (kG) has, over the past tions. files for a few magnetically sensitive lines few years, become one of the most stud- were calculated using the software ied targets among the Herbig Ae/Be stars Results of the wavelength survey of all SYNTHMAG developed by Piskunov using optical and polarimetric spectra targets, apart from the very fast rotating (1999). An example of our synthesis using (Hubrig et al., 2011). star 51 Oph, with v sin i = 256 km/s, may this code assuming a surface magnetic be seen on F. Castelli’s web page2. The field of 4.0 kG, v sin i = 0 km/s, and an strongest lines are due to hydrogen and iron abundance −4.4 dex is presented for Chemistry and magnetism in the near- helium. Also strongly seen are C i, N i, the magnetically sensitive Fe i line at l infrared Mg i, Si i, and Fe i. The only exotic spectral 15648.5 nm (Landé factor g = 2.97) in the lines identified so far were due to doubly spectrum of g Equ in Figure 2. The recent availability of ESO’s high-reso- ionised cerium, Ce iii (1584.8 nm and lution CRyogenic Infra-Red Echelle Spec- probably 1571.6 nm) in the Ap stars g Equ The second observed Ap star, trograph (CRIRES) installed at the Antu and HD 154708, and singly ionised dys- HD 154708, with a magnetic field modu- telescope on Cerro Paranal now offers prosium, Dy ii (1083.6 nm) in HD 154708. lus of 25 kG, possesses one of the the opportunity to acquire much better Apart from Ce iii and Dy ii, the only other strongest magnetic fields detected knowledge of spectral features in inter- lines identified from elements beyond the among the Ap stars (Hubrig et al., 2005). mediate-mass stars in the near-infrared iron peak were due to Sr ii, which were Stars with magnetic field strengths that (NIR) range (specifically 950–5200 nm). observed in all targets. exceed 20 kG are rare and only a very In recent months we have carried out, in few such strongly magnetic stars have a few wavelength regions, the first line The line identification in strongly magnetic been detected so far. Nearly 30 % of the identification work for the two strongly Ap stars with resolved Zeeman split lines spectral lines remain unidentified in our magnetic Ap stars with resolved Zeeman can be strengthened by comparing the study, both due to unavailability of atomic split lines, g Equ and HD 154708, the observed and expected magnetic split- data and to the complex structure of the magnetic Herbig Ae/Be star HD 101412, ting patterns. In stars with strong fields, profiles, which sometimes are the blend and one of the fastest rotating Herbig Be both the central line position and the of the central component of a line with stars, 51 Oph (Hubrig et al., 2012). The whole line profile shape, as determined the split component of a nearby line. In CRIRES observations covered the spec- by the number and relative strengths Figure 3 we present the magnetically-split tral regions around the hydrogen re- of the Zeeman π and σ components, can lines belonging to Mg i 1081.11 nm, and combination line Pag at 1094 nm, the He i line at 1083 nm, the region of the most magnetically sensitive Fe i lines at infrared wavelengths at 1565 nm and the CO band head at 2300 nm.

The stellar lines were identified using the method of spectrum synthesis. For each TW

star, we computed an ATLAS9 model Ck with fundamental parameters taken from previous studies carried out by various

authors. The models were used to com- -NQL@KHRD pute synthetic spectra with the SYNTHE Figure 2. The synthetic code (Kurucz, 1993). We adopted the line profile (dashed line) atomic line lists taken from Kurucz’s web- calculated for Fe i site1, but we substituted the log gf values 15648.5 nm with a value with those from the NIST database, of the Landé factor of g = 2.97 compared to whenever they were available. In addition, the CRIRES spectrum in some cases, we replaced the Kurucz 6@UDKDMFSGML (full line) of g Equ.

22 The Messenger 148 – June 2012 Figure 3. Magnetically split lines belonging to Mgi 1081.11 nm and Ceiii 1584.76 nm in the CRIRES spectrum of the Ap star HD 154708 are shown. The blue lines indicate the contribution TW TW

k of the telluric absorp- Ck tions. The red lines indicate the synthetic spectrum. Only the central -NQL@KHRD -NQL@KHRDC components of the magnetically split lines have been fitted in the line identification process.

'# '# 6@UDKDMFSGML 6@UDKDMFSGML

Ce iii 1584.76 nm showing a rather similar using UVES and HARPS spectra sitions of the CO molecule. The CRIRES split Zeeman structure. indicated that it may reflect a mildl Boo, spectra revealed a ring of gas in orbit or Vega-like abundance mechanism, around the magnetic Herbig Ae star In the absence of a magnetic field, the where the refractory elements are HD 101412 (Cowley et al., 2012). Individ- line at 1081.11 nm results from the super- depleted while the most volatile elements ual emission lines in the first overtone position of five transitions of Mg i, of are nearly normal (Cowley et al., 2010). band of CO are presented in Figure 4. which the one at 1081.1053 nm is the The majority of the lines identified in the The M-shaped profiles arise because of strongest. The individual transitions cor- CRIRES spectrum belong to the ele- Doppler shifts from the ring of emitting respond to different combinations of the ments Mg and Si, followed by a few lines gas which is in Keplerian rotation about lower and upper J quantum numbers. belonging to N, C, Fe and Sr. Iron is the star. Within both the lower and the upper term, underabundant, while the carbon abun- the levels of different J are separated dance is solar; nitrogen may actually be In HD 101412 CO-emitting gas is driven, from each other by less than 0.1 cm−1. slightly overabundant. or perhaps was evaporated, from a mas Thus, in the strong external magnetic sive disc feeding material to the central field of HD 154708, which is much star. Observations at high spectral reso- stronger than the atom’s internal mag- Detection of a narrow, inner CO ring lution are capable of discerning the loca- netic field, the electron coupling is around the magnetic Herbig Ae star tion and radial extent of the emitting gas. disturbed and both terms are subject to HD 101412 In Figure 5 we present the region of the the full Paschen–Back effect. The inter- CO band head. Because of convergence esting feature of the split line profiles in A further surprise was found in the long- to the head, vertical sides of the profiles the spectra of HD 154708 is that the Zee- est wavelength regions studied, which approach one another, coincide, and man σ components are broad, in particu- include the vibrational and rotational tran- eventually cross. lar considerably broader than the π components. This indicates that the spread of the field strengths over the visible stellar hemisphere is rather large, probably significantly larger than it would be for a centred dipole.

The huge rotational line broadening of the W

B9 Herbig star 51 Oph with v sin i = C kT 256 km/s prevented the reliable identification of spectral lines apart from the Mg i line at 1081.1 nm, the He i 1083.0 nm -NQL@KHRD Figure 4. The black line, and the Pag line. The spectra of the spectrum shows Herbig Ae star, HD 101412, have fewer CO emission lines R(20) lines, which accords with its abundance (right) to R(27) (left) in pattern that resembles that of the Boo HD 101412 after removal l of telluric lines using stars. Our previous study of the abun- the standard (red) star dances of the Herbig Ae star HD 101412 6@UDKDMFSGML HR 4537.

The Messenger 148 – June 2012 23 Astronomical Science Hubrig S. et al., Young and Old Intermediate-mass Stars Observed with CRIRES

Figure 5. First overtone other molecules, atoms, and ions must band head with partially also be present. Future observations cosmetic fit is shown for HD 101412. We sub- can identify and study these species to tracted one, and scaled unfold the mystery of the CO ring around the remainder verti- HD 101412. cally to fit the observations. R-branch labels TW are written above the UDk M-shaped profiles. The References overall distribution of 1DK@SH intensities is somewhat Cowley, C. R. et al. 2010, A&A, 523, A65 better fit by assuming Cowley, C. R. et al. 2012, A&A, 537, L6 T = 2500 K rather than Heiter, U. et al. 2008, J. of Physics Conf. Ser., 130, 2000 or 3000 K. 012011 Hubrig, S. et al. 2005, A&A, 440, L37 Hubrig, S. et al. 2012, A&A, in press, arXiv:1204.0652 Hubrig, S. et al. 2011, A&A, 525, L4 Kurucz, R. L. 1993, SYNTHE Spectrum Synthesis 6@UDKDMFSGML Programs and Line Data. Kurucz CD-ROM No. 18. Cambridge, Mass.: Smithsonian Astrophysical Observatory The CRIRES observations restrict the planets, as with the shepherd satellites Meléndez, J. & Barbuy, B. 1999, ApJS, 124, 527 gas to a sharply defined ring, about one of planetary rings? Why do turbulent mo- Piskunov, N. E. 1999, in ASSL, Vol. 243, Solar polari- astronomical unit from the central star. tions not tear the ring apart? zation, eds. Nagendra, K. N. & Stenflo, J. O., (Dordrecht: Kluwer Academic Publishers), 515 The radial extent of the ring is less than Ryde, N. et al. 2010, A&A, 509, 20 a third of the distance of the ring from the From a study of the relative intensities of star. The toroidal, or doughnut-shaped, the CO emission lines, it is possible to structure poses immediate questions: measure a temperature of some 2500 K Links How permanent is the structure? What (see Figure 5). This is much hotter than a 1 R. Kurucz’s website: http://kurucz.harvard.edu/ forces might act to preserve it for times planet would be at this distance. How is 2 F. Castelli’s web page: http://wwwuser.oat.ts.astro. comparable to the stellar formation time the gas heated, and how is the tempera- it/castelli/stars.html itself? Is it maintained by magnetic ture maintained? The CO can be only one structures? Is it held in place by orbiting constituent of the gas ring. A variety of

This image of the Galactic field including the star cluster NGC 6604 combines 2.2-metre MPG/ESO telescope and Wide Field Imager U, B, V, R and Ha exposures. NGC 6604 is the cluster to the upper left of the image and is part of the Serpens OB2 association. The many OB stars in NGC 6604 are part of a larger star formation region powering the H ii region Sharpless 54 and an outflow chimney perpendicular to the Galactic Plane. See Release eso1218 for more details.

24 The Messenger 148 – June 2012 Astronomical Science

POPIPlaN: A Deep Morphological Catalogue of Newly Discovered Southern Planetary Nebulae

1 Henri M. J. Boffin some of these nearby objects resemble be explained if not all the 1–8 MA stars David Jones1 the discs of the giant planets in the Solar produce a PN. Moe & De Marco (2006) Yuri Beletsky 2 System when viewed with a small tele- argued that only ~ 20% of intermediate- Mario van den Ancker1 scope. PNe are essential for the under- mass stars make a PN, while the remain- Jonathan Smoker1 standing of the evolution and mass loss der transit between the giant and white Dimitri Gadotti1 of Sun-like stars, and because they lose dwarf phases with invisible, or under- Ivo Saviane1 much of their processed material into luminous nebulae (De Marco, 2011). Sabine Moehler1 the interstellar medium, they contribute Soker & Subag (2005) predicted the Valentin D. Ivanov1 significantly to our Galaxy’s chemical existence of a large (relative to that of Linda Schmidtobreick1 evolution. In fact, the late stages in the non-spherical PNe), hidden population of and the UT1 team* evolution of Sun-like stars are the main spherical PNe that would only be found contributors of carbon enrichment in by deep searches. As noted by De Marco the Universe — the main reason that we (2011), this prediction has been partly 1 ESO are all “stardust”. Moreover, planetary borne out by MASH, a deep PN survey 2 Las Campanas Observatory, Chile nebulae can be detected out to large dis- that doubled the fraction of spherical PN tances from their strong emission lines from ~10% to ~ 20% (Parker et al., 2006; and thus serve as a means whereby Miszalski et al., 2008) and by the Deep Planetary nebulae (PNe) are amongst the motions and abundances of stars in Sky Hunters survey, which found a similar the most complex and varied of celes- the halo regions of distant galaxies can fraction in the very faint population tial objects, displaying a wide range of be investigated. (Jacoby et al., 2011). shapes and colours that are difficult to explain. Using the FORS2 instrument — The recent publication of the Macquarie/ mostly when no other observations can Morphology of planetary nebulae AAO/Strasbourg Ha PNe catalogue be performed — we have started to (MASH) presented about 1200 new, build up a homogeneous morphological Quite astonishingly, PNe display great spectroscopically confirmed Galactic catalogue of deep two-colour narrow- variation in their shapes, ranging from PNe, boosting the number of Galactic band images of newly discovered PNe. spherical through to highly asymmetric, PNe by nearly 80% and offering consid- The catalogue will be public and should including complex substructural features erable scope to address problems in soon become an invaluable tool for the like jets, filaments and rings. One esti- PN research afresh. MASH presents a community. mate has it that approximately 80% of most homogeneous sample of PNe over all planetary nebulae exhibit non-spheri- a wide evolutionary range, including cal morphologies (Parker et al., 2006). evolved PNe and those interacting with Planetary nebulae are a fleeting phenom- The debate as to why this is so has been the interstellar medium (ISM). The MASH enon lasting a few tens of thousands raging for decades (see Balick & Frank, PNe are typically more evolved, ob- of years, thought to be the final swan- 2002), and despite the numerous scured, of larger angular extent and lower

song for stars of 1 to 8 MA. During this advances in the last ten to twenty years, surface brightness than those in most dying phase, their small but hot core is a convincing answer is still lacking, other surveys. As such the MASH cata- unveiled, and starts to cool down to although the binary hypothesis is gaining logue is an invaluable source for further become a white dwarf. The ejected enve- more and more ground (De Marco, 2009). studies requiring the use of large tele- lope is ionised and emits strongly in the Stellar or even sub-stellar companions scopes. lines of several elements. The misnomer can interact with upper asymptotic giant “planetary” stems from the fact that branch (AGB) stars and shape the Miszalski et al. (2009), for example, re- ejected envelope (and therefore the sub- vealed, by cross-correlating the MASH sequent nebula) either by strong inter and OGLE-III catalogues and obtaining actions such as common envelopes follow-up imaging with 8-metre-class (Paczynski, 1976; Sandquist et al., 2008) telescopes, morphological trends in- or wider binary interactions such as wind duced by the presence of a close binary accretion and gravitational focusing companion. Canonical bipolar nebulae, (Theuns et al., 1996; Nagae et al., 2004). low ionisation structures (LIS), particularly * The UT1 team is comprised of all people involved in ring configurations, and polar outflows in the operations of Antu, the Unit Telescope 1 The binary hypothesis faces, however, an or jets were identified as being prevalent of ESO’s Very Large Telescope: Andrea Ahumada, apparent paradox: the fraction of stellar amongst PNe with binary central stars, Karla Aubel, Yuri Beletsky, Henri Boffin,Claudia companions to the progenitors of AGB and therefore associated with the influ- Cid, Lorena Faúndez, Dimitri Gadotti, Patricia Guajardo, Sylvain Guieu, Michael Hilker, Wolfgang stars (the precursor stage to a planetary ence of a binary central star. If this asso- Hummel, Valentin Ivanov, David Jones, Sabine nebula) that may interact is of the order of ciation were confirmed, it would help to Moehler, Andres Parraguez, Ferdinando Patat, 30% (Duquennoy & Mayor, 1991), so fast track the discovery of the binaries Retha Pretorius, Myriam Rodrigues, Leo Rivas, Ivo how can the fraction of non-spherical in PNe and thereby constrain their role in Saviane, Linda Schmidtobreick, Alain Smette, Jonathan Smoker, Mario van den Ancker, and PNe be as high as 80%? Several authors the shaping (and possibly formation) of Sergio Vera. have noted that this discrepancy could PNe.

The Messenger 148 – June 2012 25 Astronomical Science Boffin H. M. J. et al., POPIPlaN

Morphological studies of PNe require an This new catalogue will by no means the majority of our programme was done extensive and homogeneous database. duplicate any existing one, but on the with the MIT CCD of FORS2, some of the Schwarz, Corradi, & Melnick (1992) contrary provide much needed material observations were also performed when imaged 255 PNe, through Ha+[N ii] and required for follow-up studies. These will the blue E2V CCD was installed in FORS2 [O iii]5007 Å filters with EFOSC2 at the include, but not be limited to: derivation and nothing else could be observed. Our New Technology Telescope, during com- of statistics regarding various shapes, strategy proved extremely efficient as missioning time, when the instrument such as LIS, rings and jets; determination in P88 our programme was 95% com- rotator was not available. This catalogue of binarity and the relationship between pleted, with 230 observations done, proved very useful and continues to be the presence of certain morphological either during bad weather or twilight. For well cited. More recently, Sahai, Morris & traits and a central binary; studies of the each object, we take images, with a sam- Villar (2011) produced a catalogue of 119 interaction of PN envelopes with the pling of 0.25 arcsecond (2 × 2 pixel bin- young PNe imaged by the Hubble Space ISM; analysis of the link between PNe and ning), in Ha+[N ii] (with the H_Alpha+83 Telescope, which they used to devise a symbiotic stars; deeper and more de- FORS2 filter) and [O iii] (O iii+50 filter), and new classification system. tailed study with HST or adaptive optics exposure times between 240 s and instrumentation; kinematical studies 450 s, the majority being 300 s. For some of the newly discovered structures; and objects, we have also obtained images The POPIPlaN survey understanding the formation of the neb- in [O ii] 3727 Å and [Siii] 6723 Å as well as ula and the timing of the formation of jets. in the B- and I-broadband filters in order The availability of the MASH catalogue, to help identify the central star. The con- which provides us with the necessary A proposal was submitted to the OPC straints were set such that images could homogeneous sample to perform a de- and POPIPlaN was granted 66 hours in be taken when the seeing was below tailed morphological classification, cou- Observing Period 88 (P88) (Prog. 088.D- 1.2 arcseconds, or 1.4 arcseconds for a pled to the great collecting power of the 0514(A); PI: H. Boffin) and 66 hours in small subset, but in reality, most of the Very Large Telescope (VLT), prompted P89 (Prog. 089.D-0357(A); PI: H. Boffin). images have been taken under much us to start POPIPlaN — the Paranal A proposal has also been submitted for better seeing conditions. Some of our Observatory Project to Image Planetary P90 to finish the catalogue. images have a full width at half maximum Nebulae. The MASH survey generally of about 0.4 arcseconds! provides only modest quality images, POPIPlaN, was specifically designed as given that it was a photographic survey a filler for Unit Telescope 1 (UT1) at the from a Schmidt telescope (spatial sam- VLT, to be carried out in service mode POPIPlaN images pling of 1 arcsecond per pixel and limited by Paranal staff. The observations are dynamic range) at a relatively poor seeing done in twilight, or under thin (THN) or The images obtained in P88 unveil, as site. High-quality images were desper- thick (THK) clouds. We have analysed the expected, a wide variety of intricate ately needed and this is exactly the aim of weather statistics for the last two years shapes and structures, revealing for the POPIPlaN: to create a homogeneous and and find that there are THK conditions on first time in these objects, rings, multi complete morphological catalogue of the at least part of 15 nights per period that polar and imbricated shells and other low newly discovered MASH southern PNe, could be used by our programme, as well ionisation structures, as well as shocks. using deep, narrowband imaging with the as other occasions with THN conditions Figures 1–3 show some of the images FORS2 instrument at the VLT. and strong wind from the north. Although obtained. Photometric follow-up has already been started for those PNe showing clear rings or jets, as they most likely harbour close binaries at their centre.

Since POPIPlan is aimed at creating a catalogue of great value to the community, the data have no proprietary period, thus allowing anyone to make use of them as soon as possible and prepare follow-up observations. In addition, all the images are reduced by us and made available as FITS files and as JPEG images. A colour-composite image is also Figure 1. Colour-composite of the planetary nebula produced. Sizes and important morpho- PN G061.4-09.5, a magnificent example of an elon- gated elliptical planetary nebula, with a barrel-like waist and “ansae” marking the ends of the extended ellipse. The image is based on two exposures of Figure 2. Colour composite of PN G059.7-18.7, 240 s, taken through the Ha and [O iii] filters with showing an intricate network of low ionisation FORS2 on the VLT. The image covers 2.36 × 1.6 arc- features. Slightly to the south a pair of more distant min2 on the sky. In all figures, North is up and East is galaxies can be seen. The image size is 2.37 by to the left. 3.1 arcminutes.

26 The Messenger 148 – June 2012 Figure 3. Collage of four images of planetary nebulae imaged in POPIPlaN. (Upper) PN G247.8+04.9 (image: 5.4 by 2.6 arcminutes) is a very extended and evolved nebula showing a clear signature of interaction with the interstellar medium; (middle left) PN G250.3- 05.4 contains a slightly brighter X-shaped core (image size 2.5 by 1.4 arcminutes); (middle right) PN G224.3-03.4 is a round nebula whose southeastern edge appears greatly enhanced, most likely due to the interaction with the ISM (image size 2.5 by 1.4 arcminutes); (lower) PNG 307.3+02.0 is a canonical bipolar nebula with a bright ring-like waist (seen almost edge-on).

logical features will be indicated. In the De Marco, O. 2011, in Asymmetric Planetary Sandquist, E. L. et al. 1998, ApJ, 500, 909 future, all images will also be made avail- Nebulae 5 conference, arXiv:1010.3802 Schwarz, H., Corradi, R. & Melnick, J. 1992, A&AS, Duquennoy, A. & Mayor, M. 1991, A&A, 248, 485 96, 23 able through the VizieR interface of the Jacoby, G. H. et al. 2010, PASA, 27, 156 Soker, N. & Subag, E. 2005, AJ, 130, 271 CDS in Strasbourg. The catalogue is tem- Miszalski, B. et al. 2008, A&A, 488, 79 Theuns, T., Boffin, H. M. J. & Jorissen, A. 1996, porally available on a web page1. Miszalski, B. et al. 2009, A&A, 505, 249 MNRAS, 280, 1264 Miszalski, B. et al. 2011, MNRAS, 413, 1264 Moe, M. & De Marco, O. 2006, IAUS, 234, 463 Nagae, T. et al. 2004, A&A, 419, 335 Links References Paczynski, B. 1976, IAUS, 73, 75 Parker, Q. A. et al. 2006, MNRAS, 373, 79 1 POPIPlaN images available: http://www.eso.org/ Balick, B. & Frank, A. 2002, ARA&A, 40, 439 Sahai, R., Morris, M. R. & Villar, G. G. 2011, ~hboffin/POPIPlaN/ De Marco, O. 2009, PASP, 121, 316 ApJ, 141, 134

The Messenger 148 – June 2012 27 Astronomical Science

3D Visualisation of Integral Field Spectrometer Data

Randy Campbell1 goal of the data processing and analysis, advantage of the high spatial resolution Karina Kjær 2 of course, is to extract as much science of adaptive optics systems. Paola Amico 3 as possible. The pipeline data product of an IFS is typically a three-dimensional A volume-rendering tool was developed FITS file. These FITS files can be dis- to analyse data for IFS instrumentation 1 W. M. Keck Observatory, Hawaii, USA played using various tools, but it can be that can be used either with OSIRIS or 2 Queen’s University Belfast, challenging to visualise cubes on a two- SINFONI data. The tool1 is coded in IDL United Kingdom dimensional screen. A typical display tool and takes advantage of IDL’s object- 3 ESO will restrict the user to seeing either the oriented volume-rendering routines. A set spectra or the image in a single graphic. of tools for manipulating a datacube is This article describes an approach to vis- configured in tab widget format. A screen A tool is presented for analysing inte- ualising data that employs a volume grab of the tool is shown in Figure 1. The gral field spectrometer three-dimen- display that renders both spatial and spectrum in Figure 1 is the longer wave- sional datacubes by rendering the data spectral information simultaneously. The length subset of the K-band, using the in 3D with volumetric display tech- volume visualisation can reveal features Kn5 OSIRIS filter. The spectrum is of the niques. Volume rendering can highlight that may be difficult to discover using classical nova, V723 Cassiopeia or Nova features and aid the discovery of char- other techniques. Cas 1995 observed in 2007. The volume acteristics of astronomical objects display of V723 Cas data shows a contin- that may not be easily detected with the uum from the central point source and more common two- and one-dimen- Volume display tool very bright coronal emission features sional image and spectroscopy analysis from the nova ejecta (ring-shaped). The tools. Examples of volume analysis are Two examples of IFS instrumentation for bright emission line is from [Ca V iii] described, including Keck OSIRIS IFS use at large telescopes include SINFONI 2.3214 μm. The emission feature is spa- data for the classical nova, V723 Cas, (Eisenhauer et al., 2003; Bonnet et al., tially resolved from the expanding which exhibits a ring structure in its 2004) installed at the Very Large Tele- nebula ejected from the nova (see Lyke nova shell, and a 3D representation scope (VLT) and OSIRIS (Larkin et al., and Campbell [2009] for a more detailed of observations of the supernova 2006) installed at the W. M. Keck tele- description of the OSIRIS study of SN 1987a based on VLT SINFONI data. scope. Both of these instruments take V723 Cas).

Integral field spectrometer (IFS) instruments have been deployed at many observatories in recent years and are becoming very popular for a wide range of observational programmes. An IFS provides the ability to obtain spectra over the full extent of the instrument’s field of view, removing the limitations of a slit as in conventional spectrometers. The IFS also preserves the spatial image information over the full spectral bandwidth. The resulting data product is a three-dimensional cube that contains a spectrum for every pixel in the image and an image at every element of the spectrum. The enhanced capability comes with an Figure 1. Screenshot of increase in the complexity of the data the 3D volume-render- reduction and data analysis. ing tool for IFS data. The display shows a continuum and a bright emis- IFS instruments are very dependent on sion feature from the data reduction pipelines to support classical nova, V723 users, both in terms of real-time data Cas. The continuum is assessment and offline data processing from the central point source, but the emission to facilitate scientific publication. Since feature of the [Ca V iii] mainstream use of IFS instrumentation fine structure transition is relatively recent, analysis tools are con- is from the spatially tinuing to develop and astronomers are resolved nova shell. The spectral coverage is of finding that working with these rich data- a portion of the K-band sets can sometimes be challenging. The from 2.29 to 2.40 μm.

28 The Messenger 148 – June 2012 Classical nova example

Expansion parallax is a technique for determining distances to various subsets of astronomical objects. For example, when an object such as a supernova or a classical nova is observed following an Y outburst event and both the radial velocity and the angular expansion can be measured, the distance can be deter- X mined relatively accurately with only a few simple assumptions about the shape of the ejecta. An IFS coupled with adaptive optics (AO) affords the capability to cap- ture both the velocity and the expansion Figure 2. Manipulations of the data- simultaneously, thus improving the preci- cube of V723 Cas are shown. The sion of the distance measurement (Lyke, datacube is shown from an isometric 2009). perspective with the point source continuum removed (upper left) and the same cube is shown from the An IFS 3D datacube is a measurement of 2D spectrum view with lines overlaid intensity as a function of spatial extent showing the region to be trimmed and wavelength. When the distance to (lower left). The trimmed, continuum- subtracted cube highlighting the an object and the start time of the expan- spatially resolved [Ca V iii] 2.3214 μm sion are known, then the three axes of emission of the nebular remnant of the cube can be converted into units of this classical nova is shown at upper length in order to visualise the true shape right. of the object. The units of the two spatial dimensions are converted from angle on the sky to length based on the conver- sion of arcseconds to astronomical units (AU). The extent of the nova shell in the The volume tool has features that make With the IFS volume tool, a cube can be line-of-sight dimension can be computed it convenient for manipulating datacubes. manipulated in many ways. The volume from its expansion velocity measured The cube can be rotated to any per- can be rotated in any of the three dimen- directly from the Doppler shifted lines in spective in the xyz viewing angle. It has sions so that the cube can be viewed the spectra. Once all three dimensions options for input and output of data as from any angle, including the classical have been converted to units of length, well as various features for adjusting dis- views of an image or as a two-dimen- the cube size is adjusted such that each play parameters like stretch and colour. sional spectrum (Figure 3). side is the same size, thus rendering Other features include graphics overlays, axis display, zoom adjustment, aspect ratio adjustment and the ability to blink the display between multiple datasets.

The volume tool can easily be used to trim a cube in either the spatial or the spectral dimension. Trimming the cube can help to emphasise a region of interest, since a volume display can a have a significant region of noise that tends to “muddy” the view. Slicing in the spectral dimension is essentially customising a narrowband filter to highlight only the bandpass of interest. Figure 2 demonstrates a few of the cube manipulation abilities on the [Ca V iii] 2.3214 μm feature of V723 Cas. The unresolved point source continuum of V723 Cas has been re- Figure 3. A 2D spectrum view (left) and an image view (right) of the [Ca V iii] emission highlighting the moved here, leaving only the spatially spatially resolved velocity structure of the V723 Cas resolved emission of the nova. nova shell.

The Messenger 148 – June 2012 29 Astronomical Science Campbell R. et al., 3D Visualisation of Integral Field Spectrometer Data

Supernova example large telescope equipped with AO. How- ever this delay gives the nebular material Although the tool was originally devel- time to cool, become more rarefied, and oped at Keck for use on OSIRIS data, it diminish in brightness. Yet another chal- was subsequently adapted for use on lenge is the fact that the emission spec- SINFONI data with some relatively minor trum of SN 1987a has multiple compo- modifications. The work associated with nents, due to the rings that existed prior adopting the tool for SINFONI was done to the explosion in 1987. The rings emit during the summer of 2011 while the lead in some of the same wavelengths as the author participated in the ESO visitor supernova ejecta, but have a very differ- programme in Garching. Supernova ent velocity structure and different rela- SN 1987a is one of the objects to which tive line strengths. The multiple sources we are interested in applying the 3D anal- of emission are difficult to disentangle in ysis. This supernova is well suited for the integral field spectra. this purpose since the distance to the object is fairly well constrained due to its SINFONI data acquired in 2005, and sub- location in the Large Magellanic Cloud sequently reduced using the instrument and the time of the eruption is very well pipeline, were input to the IFS volume known. Having good values for these tool. The data in this example are over parameters potentially allows the mor- a narrow region of the H-band centred phology of the ejecta to be rendered on a [Si i]+[Fe ii] emission line blend at in 3D since the cube dimensions can be 1.644 μm. Figure 5 shows the image view converted to units of length. and 2D spectrum, displaying the spatially resolved supernova ejecta in the central However, 3D analysis of SN 1987a is portion as well as the inner ring surround- proving to be challenging for several rea- ing it. A detailed analysis of the SINFONI sons. The primary difficulty is the great study of SN 1987a is presented in Kjær distance to the object (50 kpc), which of et al. (2010). The 2D spectrum reveals the course makes detecting and resolving brighter and narrower emission lines the shell much more difficult. The obser- that are from the inner ring, whereas the vations must be taken long enough after broader, Doppler-shifted features are the explosion to allow the shell time from the high velocity ejecta. There are to expand to the point where it is large also several telluric features complicating enough resolve from Earth, even with a this part of the spectrum.

Figure 4. The true 3D morphology of the V723 Cas nebular remnant is shown. From the distance and time since eruption, the angular and velocity dimensions can be converted to create a cube with sides of equal units of length, in this case 3300 AU (5.0 × 1011 km). The 3D analysis clearly reveals the very distinct equatorial ring and polar “blobs” that are viewed both face-on (upper) and edge-on (lower) in the two different views.

the object in its true 3D morphology. Figure 4 shows the V723 Cas nova shell in [Ca V iii] emission from two viewing angles, one perpendicular to an equato- Figure 5. The 2D spectrum view (left) and the image rial ring that has formed in the nebular view (right) of SN 1987 is shown in the blended shell, and one viewing the ring edge-on [Fe ii]+[Si i] emission lines. Two sources of emission where polar knots become more evi- are distinguishable in the 2D spectrum and image dent. These features are much more evi- view: the inner ring, visible as two relatively narrow lines in the spectrum; the much broader feature, dent in the 3D display and demonstrate Doppler-shifted by the high velocity ejecta, in the the usefulness of this type of analysis. central regions.

30 The Messenger 148 – June 2012 Y

Figure 6. 3D volumetric display is shown of [Si i]+[Fe ii] blended line emission at 1.644 μm from SN 1987a.

Figure 7. Isolating the emission of SN 1987a ejecta from the inner ring emission. On the left, the spatial selection by cutting out the cube around a polygon, outlined in red, is shown. At right, the 2D spectrum of the polygon-selected cube region before (upper) and after (lower) subtraction of the peak emission from the inner cube is shown.

Figure 6 shows the volume display of the Figure 8 shows a rotated volume display Links same datacube as Figure 5, but tilted of the fully processed cube. The dimen- 1 A beta version of the IDL tool can be obtained by such that the entire volume can be seen. sions of the cube are approximately 3.0 × email to: [email protected] This allows both the spatial and spectral 1012 km on a side. Unfortunately, it is hard dimensions to be shown in one graphic, to derive a definitive shape of the ejecta the intent of which is to help reveal subtle from the volume display due to its com- features that may not be apparent in the plex and diffuse nature. The 3D graphic 2D views of the data. However, SN 1987a only gives a hint of the morphology, one does not give up its characteristics easily that is consistent with the conclusion in and any new features that were not Kjaer et al. (2010) of the SN ejecta with its already discussed in Kjær et al. (2010) are asymmetric lobes expanding at different not obvious in the volume rendering. It is angles. The 3D analysis of SN 1987a presented here as an example to demon- has proved to be significantly more chal- strate the potential capability of analysing lenging than that of the classical nova SINFONI data in this manner. V723 Cas. The V723 Cas data has much brighter coronal lines in the K-band Nevertheless, additional processing where telluric features are less of an was attempted to separate the ring emis- issue. The SN 1987a data are much more sion from the ejecta such that the true complex with blended lines of very 3D shape of the supernova shell could be high velocities within a forest of telluric visualised. Figure 7 shows a region spa- OH lines. Nevertheless, SN 1987a is tially cut from the original cube outlined one of the most compelling objects in the by a polygon. Additional processing nearby Universe and thus any attempt to included a Gaussian fit to the peak nar- understand its true nature is worthwhile. row line of each spectrum of the cube that was then subsequently subtracted to help reduce the flux contribution from References the inner ring. Figure 7 shows a compari- Bonnet, H. et al. 2004, The Messenger, 117, 17 son of the two 2D spectra with and with- Eisenhauer, F. et al. 2003, Proc. SPIE, 4841, 1548 Figure 8. 3D spatial representation of SN 1987a, iso- out the removal of the bright line. The Kjær, K. et al. 2010, A&A, 517, A51 lating the blended [Si i]+[Fe ii] emission lines of the processing helps to isolate the ejecta Larkin, J. et al. 2006, Proc. SPIE, 6269, 42 shell from the inner ring, is shown. This visualisation Lyke, J. & Campbell, R. 2009, AJ, 138, 1090 highlights the asymmetric nature of the shell as from the other sources within the original determined in Kjær et al. (2010). The cube dimen- datacube. sions are approximately 3.0 × 1012 km on each side.

The Messenger 148 – June 2012 31 Astronomical Science

First published ALMA Early Science Cycle 0 Result — Mapping of the Fomalhaut Debris Disc

Jeremy Walsh1 HST optical imaging. This implied either map. The millimetre-sized grains in the Leonardo Testi 1 an unusual atmospheric composition ring are much less affected by radiation or that it was not a true planet but a dust pressure than the smaller (sub-micron) feature, perhaps enshrouding a lower grains which have a broad tail of emission 1 ESO mass planet. Janson et al. (2012) ob- to large radii. Boley et al. suggest several tained deeper Spitzer 4.5 μm observa- explanations for the existence of the ring tions and concluded that the optical and its form; the favoured interpretation The Atacama Large Millimeter/submilli and NIR data pointed to a transient, opti- was that it is shaped by two shepherd- meter Array (ALMA) Early Science Cycle cally thin dust cloud. However, what is ing planets, similar to the shepherding 0 observations have been proceeding not disputed is that there must be one or moons of the ε ring of Uranus — Cordelia with up to 24 antennas since 30 Septem- more planets in the Fomalhaut system to and Ophelia. The required planet masses ber 2011. The first result of Cycle 0 obser- preserve a dust disc. would be around several Earth masses, vations has recently been published concordant with their non-detection by (Boley et al., 2012): ALMA 850 μm contin- The longest wavelength observations of HST or Spitzer. A further intriguing result uum mapping of the dust in the debris emission from large dust grains around from the data is a possible flux excess on disc around the nearby A3V star Fomal- Fomalhaut were made by the Australia the star itself, suggesting an additional haut (the naked eye star alpha Piscis Telescope Compact Array at 7 mm (Ricci dusty region much closer to the star. Austrini, V mag. 1.16). These observations et al., 2012) at a spatial resolution of were observed with only 13 and 15 anten- about 12 arcseconds. The higher resolu- ESO astronomer Bill Dent (ALMA, Chile), nas, but amply demonstrate the quality of tion ALMA observations were performed one of the observing team, concluded science that ALMA can achieve and pro- in the continuum at 850 μm which is in the press release: “ALMA may be still vide a foretaste of what can be expected mostly sensitive to emission from milli under construction, but it is already the in the coming years. metre-sized dust grains. ALMA was used most powerful telescope of its kind. This in its compact configuration with base- is just the beginning of an exciting new The presence of a dusty disc around the lines from 14 to 175 metres and with era in the study of discs and planet for- young main sequence star Fomalhaut Band 7 (275–373 GHz). The spatial res mation around other stars”1. had been known since the detection of olution (synthesised beam) was 1.5 by an infrared excess (Aumann, 1985) with 1.2 arcseconds, but the dusty ring was the Infrared Astronomical Satellite (IRAS). too large to be encompassed by a single References The filigree structure of the disc was ALMA primary beam, so ALMA was Aumann, H. H. 1985, PASP, 97, 885 revealed by Hubble Space Telescope pointed at the northern half of the disc Boley, A. C. et al. 2012, ApJ, 750, L1 (HST) imaging with the Advanced Cam- (where Fomalhaut b lies). Chiang, E. et al. 2008, ApJ, 693, 734 era for Surveys (ACS) with a coronagraph Janson, M. et al. 2012, ApJ, 747, 116 (Kalas et al., 2005). The disc is slightly Figure 1 shows the ALMA map (corrected Kalas, P. et al. 2005, Nature, 435, 1067 Kalas, P. et al. 2008, Science, 322, 1345 elliptical in appearance with a major axis for the response of the primary beam) Marengo, M. et al. 2009, ApJ, 700, 1647 length of about 140 Astronomical Units from Boley et al. (2012) superimposed on Ricci, L. et al. 2012, A&A, 539, L6 (AU) and eccentric with respect to the the HST ACS image from Kalas et al. stellar position. The puzzle about discs/ (2005; 2008). This reveals a very narrow Links rings around main sequence stars is that distribution of millimetre-sized grains with they cannot be the original proto-stellar a radial width of only 16 AU; moreover the 1 ESO press release: http://www.eso.org/public/ disc, which would have long since dis inner and outer radii of the disc are much news/eso1216/ sipated, but must be actively replenished sharper than indicated by the sub-micron or trapped to be detected at all. From sized particle distribution from the HST a second epoch of HST ACS imaging, Kalas et al. (2008) detected the proper motion of a bright spot in the outer disc around Fomalhaut and proposed this as a planet candidate (Fomalhaut b) with a mass of up to three Jupiter masses. The interactions between this candidate planet and the debris disc could explain the eccentricity of the dust ring, well measured with HST (Chiang et al., 2008). Figure 1. Superposition of part of the ALMA (ESO/NAOJ/NRAO), NASA/ESA HST NASA/ESA Hubble Space Telescope However subsequent near-infrared (NIR) ACS image of the scattered optical imaging with the Spitzer Space Tele- light of the Fomalhaut debris disc scope at 3.6 and 4.5 μm (Marengo et al., (from Kalas et al., 2005, 2008) and the ALMA 850 μm continuum image (from 2009), did not detect this planet when Boley et al., 2012) of the northern sec- it was expected to be brighter than in the tion of the disc.

32 The Messenger 148 – June 2012 Astronomical Science

X-shooter Spectroscopy of Massive Stars in the Local Group and Beyond

Hugues Sana1 general relativity. Massive stars affect the portant role in explaining the observed Alex de Koter1, 2 dynamical evolution of the star clusters in frequencies of different evolutionary Miriam Garcia 3, 4 which they reside and are thought to play phases and of supernova types. Olga Hartoog1 a crucial role in the formation and evo Lex Kaper1, 5 lution of galaxies. They are also the can- With the latest generation of 8–10-metre- Frank Tramper1 didate first stars, anticipated to have re- class telescopes, massive stars in more Artemio Herrero 3, 4 ionised the Universe some few hundred distant galaxies can now be individually Norberto Castro 6 million years after the Big Bang. Given resolved, allowing us to probe a wider their importance for various fields of astro- span in environmental properties, albeit physics, a clear understanding of the for- so far mostly at low spectral resolution 1 Astronomical Institute Anton Pannekoek, mation and evolution of massive stars is (R ~ 2000) and within the Local Group Amsterdam University, the Netherlands essential. (e.g., Bresolin et al., 2007). Although quite 2 Utrecht University, the Netherlands a number of exciting objects have been 3 Instituto de Astrofísica de Canarias, At optical and near-infrared wavelengths identified, detailed quantitative spectro- La Laguna, Tenerife, Spain massive stars emerge from their natal scopic analyses of the most massive 4 Departamento de Astrofísica, Universi- clouds typically within the first million stars have remained cumbersome for dad de La Laguna, Tenerife, Spain years after formation, such that a census obvious reasons: low signal-to-noise ratio 5 Vrije Universiteit Amsterdam, of their masses, rotation rates and multi- and/or modest spectral resolution com- the Netherlands plicity characteristics may provide impor- plicate (or prevent) the removal of nebular 6 Institute of Astronomy & Astrophysics, tant insight into the end product of the emission, among other corrections. National Observatory of Athens, Greece star formation process. A detailed under- Besides enabling a better nebular sub- standing of their evolution further requires traction, the higher spectral resolution the identification and analysis of stars offered by X-shooter allows a more accu- Combined with the collecting power of in various evolutionary phases up to the rate surface temperature, gravity and the Very Large Telescope, X-shooter pre-supernova stage, thus deriving evo mass-loss determination. It also allows is the most sensitive medium-resolution lutionary connections between these for the analysis of weak metallic lines, spectrograph currently in operation, phases. Comparisons between obser crucial to derive abundances and accu- allowing us to perform quantitative vations and stellar evolution models must rate projected rotational velocities. These spectroscopy of objects that, up to be done for stars in different chemical quantities are the key to establish and now, were deemed too faint. In addition, environments as the ratios of stars in characterise the evolutionary stages of with its unique wavelength coverage, different phases (e.g., that of O to Wolf– massive stars and their feedback. Here X-shooter provides access to an un- Rayet stars), as well as the ratio of we report on the first analyses of massive precedentedly large number of diag- Type Ib/c to Type II supernovae, are found star mass loss at sub-SMC metallicity, nostic lines. We review our recent work to be metallicity dependent. With most which appears to contradict our expecta- on massive stars in Local Group dwarf long-duration gamma-ray bursts occur- tions. galaxies and in NGC 55, an irregular ring at low metallicity and the anticipated galaxy in the foreground of the Sculptor role played by massive stars in the early Group. The observations were obtained Universe, including its re-ionisation and Mass loss at low metallicity as part of the ESO Science Verifica- galaxy formation, it is particularly interest- tion Programme and the NOVA–Dutch ing to study massive stars in low metallic- The gas outflow of hot massive stars is Guaranteed Time Observation Pro- ity environments. driven by radiation pressure on metallic gramme. The aim is to investigate the ions in the star’s atmosphere, and conse- evolutionary status of high-mass stars These considerations have motivated the quently its strength. is predicted to scale in various environments and to test study of massive stars in the Large and with metallicity (M  Z 0.69 ± 0.10; Vink et al., the theory of radiation-driven stellar Small Magellanic Clouds (LMC and SMC 2001). This prediction has been verified winds at metallicities below that of the respectively). Massive OB, Luminous for massive stars in the Galaxy and in the Small Magellanic Cloud. Blue Variable (LBV) and Wolf–Rayet (WR) Magellanic Clouds observed in the VLT– stars in the Magellanic Clouds have Flames Survey of Massive Stars (Evans et

been studied intensively in the past dec- al.,. 2008), where the empirical relation Massive stars are linked to a wide vari- ade (e.g., Mokiem et al., 2007; Evans et M  Z 0.78 ± 0.17 was found (Mokiem et al., ety of astrophysical processes and phe- al., 2008). One important result that 2007). The theory has, however, never nomena. Their intense radiation fields, has emerged from these studies is that been tested at sub-SMC metallicity. Be- strong stellar winds and violent super- the rate of gas outflow driven by radia- cause the evolution of massive stars is nova explosions stir the ambient interstel- tion pressure on spectral lines is both greatly influenced by the amount of mass lar medium, which is typically a site of predicted and found to be metallicity, Z, and angular momentum lost through star formation. Their explosions produce dependent in a range from ZA to 0.2 ZA. their strong stellar winds, determining the the neutron stars and black holes that This mass-loss rate versus metallicity wind strength was one of the main goals are used to test extreme physics and dependence is expected to play an im- of our quantitative spectroscopic analysis.

The Messenger 148 – June 2012 33 Astronomical Science Sana H. et al., X-shooter Spectroscopy of Massive Stars

TW . 5( " ((( Ck !l6 '''' '' ''D (( ' 'D(( '¡ 'D((( 'b 'D(( 'a 'D(( 'D(( '` -NQL@KHRD l5

6@UDKDMFSGÄ

45!5K2 " (5 TW k . 5( 'D(( . 5 " (5 'D(( !l6 'D(( '_ -NQL@KHRDC l5

6@UDKDMFSGÄ

Figure 1 (above). Part of the X-shooter normalised than predicted mass-loss rates for an- Figure 2 (below). The wind momentum–luminosity spectra of two sources in IC 1613 are shown: A13 other two massive stars in IC 1613 diagram is shown. Dashed lines indicate theoretical (O3V, lower spectrum in the two panels) and B17 predictions from Vink et al. (2001) for different metal- (WO3, upper spectrum in the two panels). The WO (objects 7 and 8 in Figure 2). Although licities. Solid lines and shaded areas indicate the spectrum has been reduced in flux by a factor of five more stars need to be observed and observed wind momentum–luminosity relations for and shifted to fit the panel. The main spectral lines analysed to draw firm conclusions, these the Galaxy, LMC and SMC samples (Mokiem et are labelled. The vertical dashed line marks the tran- unexpected results may have interesting al., 2007). The shift between the predictions and the sition between the UVB and VIS arms of X-shooter. empirical measurements can be explained by implications. For example, the single- wind inhomogeneities, which are not included in the star channel to produce long-duration analysis. Our observations in metal-poor galaxies gamma-ray bursts depends on a star are overplotted, objects 1–6 are from Tramper et al. The Local Group dwarf galaxies IC 1613, retaining a rapidly spinning core at the (2011). Objects 7 and 8 are from Herrero et al. (2012) and Herrero et al. (2011), respectively. Although the the Wolf–Lundmark–Melotte (WLM) gal- end of its life, and the star therefore can- error bars are large, the positions of objects 5, 6 and axy and NGC 3109 are ideally suited to not lose too much angular momentum 8 are incompatible with theoretical predictions. Fig- probe the properties of massive stars in through its wind. This result would thus ure adapted from Tramper et al. (2011). low-metallicity environments. These galaxies all have a metallicity of approxi- ("l 5E &@K@WX mately ZA /7 (i.e. lower than that of the ("l KKK +," SMC), a very low foreground reddening, ("l! K and a young stellar population. Their dis- ("l"KKKE 2," tances are such that one can still resolve 6+,l K@ and individually study the brightest ob- -&"lK ("l KKK jects. We have thus obtained X-shooter ("lKE spectra of several massive stars in these galaxies (four in IC 1613, and one each LN L in WLM and NGC 3109). The targets were # chosen to probe the whole range of NF + O-type stars, with spectral types ranging from O3 V to O9.5 I. An example spec- C trum is displayed in Figure 1. 99 We find that the stars in our sample appear to exhibit surprisingly strong 9 9 winds, with a mass-loss rate expected for 9 9 ,NJHDLDS@K 9 9 5HMJDS@K LMC metallicity (objects 2–6 in Figure 2; Tramper et al., 2011). In a similar study,

Herrero et al. (2011) also report stronger +NF++

34 The Messenger 148 – June 2012 Figure 3. The Q vs. U–B imply that fewer progenitors are produced through this channel. Also the sin- diagram of IC 1613 is shown with the locus of gle-star population at low metallicity O and B stars. Black would produce more Wolf–Rayet stars dots represent good than currently thought, as a conse- quality photometric data quence of the higher mass-loss rate. This for IC 1613 stars. For each Q-horizontal band, would lead to an increase of the number l the central box corre- of Ib and, potentially, Ic supernovae. sponds to unreddened or moderately reddened !NW Herrero et al. (2012) recently re-analysed objects. Large symbols mark the position of 0 object 7 in Figure 2 and concluded that stars with known spec- the object position in the wind momen- tral type (from Bresolin tum-luminosity diagram can be recon- . RS@QR !l! et al., 2007). X-shooter observations from ciled with a sub-SMC line-driven wind l 61 !l! Tramper et al. (2011) are model, assuming that the object is a fast !D +@SD ! marked with red stars. rotator seen pole-on with an unusually Green stars mark the rapid acceleration law for its stellar wind; D @MCK@SDQ position of newly con- it is this solution that is presented in Fig- 7 RGNNSDQC@S@ firmed O-type stars from low-resolution VLT- ure 2. Whether such a scenario can ex- !NW -DV. RS@QR VIMOS or GTC-OSIRIS plain the other three problematic objects l spectroscopy and illustrate that O-type stars in Figure 2 remains to be investigated. l l l From a purely statistical point of view, concentrate in Box 1. 4m! Figure adapted from it seems unlikely that four high-inclination Garcia et al. (2009). fast rotators have been picked out in a sample of only eight objects. Clearly, a tral type, U–B holds the information 60%. The success rate of the GTC- larger observational sample is needed about whether the star is reddened or OSIRIS list, that also uses evolutionary to understand the origin of this apparent not. Known O stars and B supergiants masses and GALEX detection, reaches discrepancy between the observations in nearby resolved galaxies are mostly 70%: 9 out of 13 candidates are O stars, and the line-driven wind theory at sub- found in a progressing sequence in the while the other objects are early-B stars. SMC metallicity. U–B vs. Q diagram (marked with boxes 1 and 2 in Figure 3), and usually have Q ≤ To summarise, the VLT-VIMOS and GTC- –0.4. OSIRIS observations have provided us Searching for new massive stars in with a list of 23 newly identified O stars IC 1613 The target selection method thus pro- (see Figure 4) to be followed up with ceeds as follows. Starting from a cata- X-shooter. This multiplies the sample of As currently only a small number of mas- logue with small photometric errors known O stars in IC 1613 by a factor of sive stars are known in galaxies beyond (< 0.05 mag) to minimise the uncertainty four and will allow for a much larger-scale the Magellanic Clouds, a large effort on Q, “blue-Q” stars with Q < –0.8 are study of the winds of early-type stars at to identify new O-type stars has been first selected; this provides a list of OB very low metallicity. initiated at the Instituto de Astrofísica de star candidates. In order to separate the Canarias (IAC) in Tenerife. This identifi O- and B-type stars, additional informa- cation proceeds in two steps: a photo- tion is needed (see Garcia et al., 2009). Beyond the Local Group metric pre-selection of the most promis- The final list of O-star candidates is made ing massive star candidates, followed of “blue-Q” objects with evolutionary To test even further the capabilities of by a spectroscopic confirmation using masses over 30 MA as derived from col- X-shooter in this field of research, we set low-resolution multi-object spectroscopy. our–magnitude diagrams (Garcia et al., out to perform quantitative spectros- 2010) and a detection in far ultraviolet copy of some of the most massive early- The photometric pre-selection is based images from the GALEX satellite (GALEX- type stars beyond the Local Group. The on the reddening-free parameter Q. Cal- FUV). NGC 55 galaxy lies in front of the Sculp- culated from broadband Johnson photo- tor group, at a distance of about 2 Mpc metric colours, Q = (U–B) – 0.72(B–V) The method has been tested in IC 1613 and is similar in shape and metallicity increases monotonically from spectral using low-resolution (R ~ 2000) spectra to the LMC. The population of massive type O to A. Because of its definition the taken with the VLT-VIMOS and GTC- blue stars in this galaxy has been identi- Q-parameter depends on the adopted OSIRIS instruments. The success rate of fied in the context of the Araucaria pro- reddening law and is subject to larger this pre-selection method is impressive. ject (Gieren et al., 2005). Classified as an photometric errors than for individual fil- For VIMOS, the pre-selection was based early-O supergiant from published low- ters. OB stars occupy a well-defined only on the Q-parameter. Fourteen O stars resolution FORS2 spectra (Castro et al., locus in the U–B vs. Q diagram (see were newly identified out of a sample 2008), we selected source C1_31 as a Figure 3). While Q is an indicator of spec of 24 candidates, thus a success rate of candidate very massive star in this galaxy

The Messenger 148 – June 2012 35 Astronomical Science Sana H. et al., X-shooter Spectroscopy of Massive Stars

sidered C1_31 to be a small stellar cluster rather than a single source. Indeed the projected size of our entrance slit corre- sponds to a physical distance of just below 10 pc, i.e. large enough to contain a small open cluster such as Trumpler 14 or NGC 6231. Pursuing this solution, we can reproduce all observed spectral features, the properties of the surrounding ionised region and the visual brightness of the target by combining about ten late-O/early-B (bright) giants, and one or two WN stars, a class of WR stars that can be very hot, but do not show very strong carbon lines (which would have been prominent in the target spectrum).

This work illustrates an inherent difficulty in extragalactic stellar spectroscopy, i.e., the risk of observing a cluster (or an unresolved multiple object) instead of a single star. Thanks to the unique combination of high resolution and large wavelength coverage, allowing many different diagnostic N lines to be observed, X-shooter can play a critical role in unveiling the composite E character of such objects. Obviously the cluster composition that we proposed for Figure 4. IC 1613 three-colour composite image spectra (see Figure 3 and Tramper et al., 2011) while NGC 55 C1_31 may not be the unique made with INT-WFC images taken with the Ha- (red) green squares show the location of newly identi- solution, but the conclusion that NGC 55 and V-band (green) filters plus GALEX’s FUV-channel fied O-type stars from low-resolution VLT-VIMOS or (blue). Red squares mark the objects with X-shooter OSIRIS-GTC spectroscopy. C1_31 is not a single star but a cluster that contains at least one very hot WR star, is robust. Higher angular resolution (Figure 5), and observed it with X-shooter which allowed us to investigate the nature is a must to further disentangle such a during Science Verification. of the source and its stellar parameters. group of stars and to study the evolution- A model resembling a late O star could ary stage of the identified population. The spectrum that we obtained has been reproduce all the hydrogen and helium a riddle (Hartoog et al., 2012). Most of line profiles, except for He ii 4686 Å and the Balmer lines and the He i lines were Ha. These lines, present in emission in Future prospects strongly affected by nebular contamina- our X-shooter spectrum, have a full width tion, in stark contrast with previous low- at half maximum of about ~3000 km/s, With the advent of the European resolution data. Yet, the resolving power and are reminiscent of the lines found in Extremely Large Telescope (E-ELT) it will of X-shooter was sufficient to separate WR star spectra. However, peaking at become possible to resolve stellar popu- the wings of the stellar photospheric lines about 20% of the continuum level, these lations in a representative sample of from the nebular emission affecting the lines are not very strong, and definitely galaxies of different morphologies in and line cores (see Figure 5). The absence of too weak for typical WR stars. beyond the Local Group, such as the the Heii 4200,4541 Å lines in the spec- spiral-dominated Sculptor and M83 trum was, given our signal-to-noise ratio, The large spectral coverage of X-shooter groups and starburst galaxies such as setting a firm upper limit to the effective allowed us to estimate the extinction M82. The high contrast and sensitivity of temperature of about 35 000 K, in contra- directly from our data by a comparison of wide-field (up to 10 arcminutes) adaptive diction with the proposed early-O super- the (relative) flux-calibrated spectrum with optics, routinely providing a spatial reso- giant classification. The properties of the the spectral energy distribution of a lution a factor of ten better than seeing- superposed nebular spectrum, however, standard hot star model. Given its extinc- limited observations at the VLT, will suggested a very hot ionising source, tion-corrected flux, we estimated the provide the opportunity to simultaneously with a temperature of about 50 000 K. source to be about a factor ten more obtain spectra of several hundreds of luminous than typical early-O supergiants. individual (massive) stars within a tar- We compared the observed spectrum geted galaxy. Several concepts of the with synthetic spectra from a grid of In order to synthesise these different ele- required E-ELT multi-object spectrograph FASTWIND stellar atmosphere models, ments into a consistent picture, we con- (OPTIMOS and EAGLE) have been

36 The Messenger 148 – June 2012 explored (Hammer et al., 2010; Le Fèvre et al., 2010; Morris et al., 2010). For the study of massive stars, wavelength coverage as far to the blue as possible would be required, but also the near- infrared provides valuable spectral diag- ࣳ nostics. For the first time we will be able to explore the properties of massive stars over the full range of environments, from the lowest metallicities up to the sites of violent star formation in starburst galaxies.

References

Bresolin, F. et al. 2007, ApJ, 671, 2028 Castro, N. et al. 2008, A&A, 485, 41 Evans, C. J. et al. 2008, The Messenger, 132, 25 Garcia, M. et al. 2009, A&A, 502, 1015 Garcia, M. et al. 2010, A&A, 523, A23 Gieren, W. et al. 2005, The Messenger, 121, 23 Hammer, F. et al. 2010, The Messenger, 140, 36 Hartoog, O. et al. 2012, MNRAS, 422, 367 Herrero, A. et al. 2011, IAUS, 272, 292 Herrero, A. et al. 2012, arXiv:1206.1238 &B Le Fèvre, O. et al. 2010, The Messenger, 140, 34 &B Morris, S. et al. 2010, The Messenger, 140, 22 Mokiem, M. R. et al. 2007, A&A, 473, 603 Tramper, F. et al. 2011, ApJ, 741, L8 Vink, J. et al. 2001, A&A, 369, 574 1

(

Ck Figure 5. Top panel: MPG/ESO 2.2-metre WFI colour-coded image (B, V, Ha) of NGC 55 is shown. a ` b ' Middle panel: zoomed-in FORS2 Ha image around ' ' -NQL@KHRD the position of C1_31; the rectangles indicate the projections of the X-shooter entrance slit during our ( ( three different observations. Bottom panel: Co- ( (( ( ( (( (( ( ( 'D 'D 'D 'D 'D 'D 'D 'D 'D 'D added C1_31 spectrum with the main spectral features identified. Figure adapted from Hartoog et al. (2012). 6@UDKDMFSGML

NGC 4945, shown here, is an SB barred spiral galaxy in the nearby Centaurus A group of galaxies. The colour image was formed from exposures taken with the 1.5-metre Danish telescope at the La Silla Observa- tory in B-, V- and R-bands. NGC 4945

ESO/IDA/1.5-metre Danish/R. Gendler and Thöne C. has a heavily obscured Seyfert 2 active galactic nucleus which has been extensively studied. See Picture of the Week 1007 for more details.

The Messenger 148 – June 2012 37 Astronomical News UT: 21:31 UT: 2012-06-05 21:15 UT: 2012-06-05 programme outreach the of part as astronomy of wonders the about children in Chile, exciting Chilean school student ESO an Gourgeot, Florian See p. 48 for details. for p. 48 See transit for details. of-the-alma-antennas-before-the- events/429-venus-as-seen-by-one- servatory.org/en/announcements- http://www.almaob See taken. were Chajnantor after the shortly images at set Venus Sun; the of disc the towards Venus of approach the show apart, 16 minutes taken and metres 3milli of awavelength at tained ob- images, 2012. two The 6 June on transit the before just Sun the and Venus of image an produce to used was antennas ALMA the of One Viaje a las Estrellas alas Viaje .

ALMA Astronomical News

Renewable Energy for the Paranal Observatory

Ueli Weilenmann1 vatory started to look into possible solu- (VST). In the telescope area, the four unit tions to control its energy costs. One telescopes (UTs), the VLT Interferometer obvious option is the production and use (VLTI) and the VST consume 67% of the 1 ESO of renewable energies. total power of approximately 1200 kW. A breakdown of the power use across the There are however some caveats and Observatory is shown in Figure 1. The operation of observatories at boundary conditions that have to be remote sites presents significant taken into account: Beyond purely economic considerations, demands for electrical energy. The – Paranal is operating in “island mode” the long-term impact of observatory use of renewable energy may become and has no connection to the Chilean operations on global climate and environ- the solution to cope with the ever- power grid. mental sustainability should also be ad rising prices for electrical energy pro- – Solar energy cannot easily be stored, dressed. The carbon footprint of the duced from fossil fuels. There is not either as electrical or thermal energy. Observatory is, at 22 000 metric tonnes

only a purely commercial aspect, but – Wind energy is highly intermittent of CO2 per year (see Figure 2), at a level also the carbon footprint of observa- and requires a full back-up by conven- that is hardly sustainable. (The cost to

tory activities has to be considered. As tional energy generators. offset the entire CO2 emission of the a first step on the way to a “greener” – Any solution adopted for Paranal Paranal Observatory would be in the Paranal Observatory, we propose the should be compatible with the range of € 500 000 per year [at € 23 per

installation of a solar cooling system for European Extremely Large Telescope tonne of CO2]). The CO2 emission of the the cooling of the telescope enclosures, (E-ELT) project which is planned to be Observatory translates into approximately

using the abundant insolation that is built on the nearby Cerro Armazones 46 tonnes of CO2 per peer-reviewed VLT freely available in the north of Chile. peak, and not pose any precedents science paper per year, which itself is

Further into the future, feasible options or dependencies for this new project. equivalent to the yearly CO2 footprint of for photovoltaic and wind energy – The proposed investment should be ten people at the current world average.

could supply the needs of the Paranal reasonable and the time for return The main contributor to the CO2 foot- Observatory in a sustainable manner. on investment should be as short as print is the electricity generation by lique- possible. fied petroleum gas (LPG, consisting of butane/propane). A reduction in the num- The location of the Paranal Observatory Paranal power consumption has re ber of international and domestic flights, in the Atacama Desert has, apart from its mained stable over the past few years, i.e. by eliminating visitor mode observa- remoteness, two other important advan- despite the addition of the VISTA survey tions, would only reduce the footprint by tages: the clear night-time sky in northern telescope and the VLT Survey Telescope some 10%, but would have an undesired Chile provides astronomers with more than 320 clear nights per year; the clear day-time sky also provides abundant 12 % Figure 1. The breakdown of average sunshine. But 20 years ago, when oil was electrical power distribution between 4% the various elements of the Paranal still cheap, little thought was given to Observatory (100% = 1200 kW). the fact that the situation for economic 8% provision of energy to the observatory Base camp could one day change. It is increasingly 67% Telescope area difficult for the Paranal operations budget 9% to accommodate the growing financial VISTA demand for electrical energy production. Residencia The increasing energy costs cannot be Others predicted in an easy way for the near future and depend heavily on exchange rates, oil prices and the global economy. Domestic ﬂights Other transport 8% 6% Between 2003 and 2010, electricity International ﬂights 1700 1400 Accommodation 12% prices in Chile rose on average by 6.8% 2700 1200 5% per year, according to statistics from the Organization for Economic Co-operation 500 Staff commuting and Development (OECD1). The renewa- 5% Power generation 12 600 ble energy share in Chile was 49% in 57% 20092 with, however, a downward trend anticipated in the coming years as coal- Figure 2. The breakdown of the fired power plant projects, presently carbon footprint for the operation of the Paranal Observatory in terms under discussion, begin to be realised. Secondary emission 1900 of tonnes of CO2 equivalent and by Confronted with these facts, the Obser- 9% percent.

The Messenger 148 – June 2012 39 Astronomical News Weilenmann U., Renewable Energy for the Paranal Observatory

impact on the operational model of the range of 20%, while thin-film cells are the return time on investment is. This Paranal. Connection to the Chilean grid just about crossing the 15% level. The fact should not be left out of the discus- would also not improve the carbon costs for PV have now almost reached sion. During 2010 and 2011, we looked footprint much, once coal dominates the the magic barrier of 1 €/W, which is into possible solutions to, at least energy mix in Chile. This demonstrates considered to be the price where PV partially, provide the Observatory with that a real reduction of the CO2 emission becomes economically feasible. Manu- renewable energy and explored one idea can only be achieved if electricity is gen- facturers of PV technology now guaran- that would in fact be in line with the con- erated from renewable sources. tee a service life of more than 20 years. siderations listed above: a solar cooling system for the VLT telescope enclosures. Wind energy on the other hand is attrac- Alternatives tive from the point of view of simplicity, but has some drawbacks, such as inter- The cooling of the VLT enclosures Looking at all the known technical options mittency, that could have a more serious and discarding those that are not suita- effect at Paranal compared to PV, for Paranal uses three chillers that produce ble for the Observatory — either due to example. Wind turbines cannot be cooled media for the cooling of all the its mountain location, or for other rea- installed in the immediate vicinity of the electronic equipment, the scientific instru- sons — there remain basically only three Observatory due to the long turbulence ments, the buildings and the enclosures alternatives for energy generation from tail they cause. Siting them further away of the VLT. These chillers operate almost renewable sources: would result in higher installation costs. continuously, as the demand for cooling – solar thermal energy, harvested either Estimates show that two wind turbines of during the night at 660 kWth (thermal) by concentrating or flat collectors; the 800 kW class would cover ~ 40% of is only about 30% lower than during the – solar electricity, by means of photo the Observatory’s energy demand. day. This extra demand of around voltaic panels in staring or tracking 300 kWth during the day is only used for mode; With the possibility of getting a connec- air conditioning the VLT enclosures. – wind energy, with windmills on a nearby tion to the Chilean power grid sometime mountain ridge, avoiding increased tur- in the near future, both PV and wind During the day, there is an almost per- bulence at the observing site. are highly attractive solutions for the fect correlation between cooling demand future and should be kept on the alterna- and availability of solar energy. With Solar thermal energy is the easiest option tive energy agenda of Paranal. Under an adsorption or absorption system, this of all, as it uses known, simple and cheap conservative assumptions, up to 50% of thermal energy can be transformed into technology that has been available for the energy demand could be covered cooling energy and supply the air- many decades. Using concentrating col- using these three technologies. conditioning systems in the telescope lectors, processing of heat up to 600 °C enclosures. The load of at least one can be achieved to drive Stirling engines Expanding on these ideas, business chiller could be taken over and approxi- or Rankine cycle turbines, while flat col- models like BOO (Build-Own-Operate) or mately 150 kW of electrical power could lectors can deliver hot media just below DFBO (Design-Finance-Build-Operate) be saved. This would correspond to the boiling point of water- or glycol-based could be considered as well, also in the 15% of the generated power and about coolants. context of the E-ELT. Due to their intrinsic 5% of the energy, translating into savings modularity, PV fields and wind turbines of the order of €150 000 per year at Photovoltaic (PV) energy is a modern can be added with little effort and at will present energy prices. This solution is technology, but ripe for industrial use, to an existing system and cope with simple and does not imply very sophisti- and it has been proved that it can be growing demand and increasing energy cated technology. Several solar cooling competitive in terms of reliability and cost costs. The higher energy costs rise, plants are already operating in southern and is almost maintenance free. Crystal- the sooner alternative solutions become Europe and the Middle East and compare line solar cells now reach efficiencies in economically interesting and the shorter in terms of reliability to conventional

AIR TREATMENT UNIT Figure 3. A solar-pow- AIR TREATMENT UNIT AIR TREATMENT UNIT AND PRESSURIZATION ered cooling circuit for FROM one Unit Telescope is EXTERNAL SIDE M shown. See text for F F F explanation of the various elements. The Adsorption/Absorption F F F ad/ab Cooling System Dry Chiller 1 solar circuit is shown in Coolers yellow; ab(d)sorption Solar Collector 22 22 22 Array cooler in green; dry M M M cooler (red); cooled 18 18 18 media delivery (blue) for Hot Water 5 2 1/2' 2 1/2' 2 1/2' Storage three air-handling units Tank 8 8 8 at the telescopes (only one shown).

40 The Messenger 148 – June 2012 Figure 4. Proposed into hibernation, lights in corridors and location of the solar telescope tunnels could be motion con- array collector field at UT3 trolled and office equipment could either UT4 the Paranal Observa- be switched off completely or put into UT2 tory; the connection Cable duct to the telescope enclo- hibernation, etc. There are many oppor- sures is shown. N 10000 UT1 tunities to tackle the energy issue also VLTI from the side of savings and we will con- Control building tinue to address them over the coming years. N

Collector ﬁeld N 9800 Outlook

Access road Unfortunately, when the VLT project

2570

2565 was conceived in the early nineties,

2560 renewable energy concepts were not on 2555 2550 2540 2545 the agenda. To refurbish the Paranal 2535 N 9600 2535 2525 2530 Observatory now with renewables would 2520 be expensive and only partially lead to

2515 an ideal solution. Compromises have to plants with electrical compressor chillers. The absorption machine would be placed be made and the heritage from sus The temperature that an absorption in a container nearby and the piping tainability not designed-in right from the cooler can deliver does not however would be routed through existing ducts to beginning will always remain. Neverthe- N 9400 E 4400 reach the low levels E 4600 that are required E 4800 by the 5000 E control building E 5200 and the telescopes. less rising energy prices will force us to the technical equipment in the telescopes go this route and the solar cooling project (3–5 °C). There are two possible ways to is just at the beginning of the green path implement this system on Paranal. Other energy savings that the Paranal Observatory is willing to take! Astronomy is one of the oldest sci- One solution would supply the cooled Beyond the large-scale projects for the ences and perhaps could be considered media directly to the air-handling units implementation of renewable energies, as one of the purest. We should try to located on the outside of the VLT enclo- energy saving also has to be addressed. avoid contributing to the pollution of the sures. Figure 3 shows the diagram of the The awareness of the Observatory staff atmosphere of our planet, and make use system: hot water from the solar panels with respect to energy saving is growing of the abundant energy that the nuclear (yellow) acts as a thermal compressor in and together with technical solutions, fusion reactor at the centre of our Solar the absorption chiller3 (green) and evapo- can reduce the waste of energy. Many System is producing for free.… rates the water from a water / lithium proposals have been made, but they are bromide solution. The water is then con- sometimes difficult to put into practice. densed by means of the dry cooler loop Acknowledgements (red) and absorbed back again into the On the larger scale, pumps may be I would like to thank P. Vanderheyden and lithium bromide. The cold water (blue), switched off if they are not in use or idling, C. Ramirez for their valuable input and discussions produced in the absorption process, then recirculation pumps and fans could be towards helping this idea fly. Many other Paranal feeds the air-handling units (black) of upgraded with variable speed control. staff members contributed with their ideas and kept the telescope enclosures. The other pos- Capacitor banks for the compensation the spirit high to contribute to energy savings/renewable energy and promoting a greener Observatory. sible solution would be to use the solar of reactive power are currently being Special thanks go also to R. Tamai and A. McPherson energy circuit to pre-cool the return flow installed on the low voltage grid and will for sharing their plans for E-ELT power generation. from the cooling system and feed this save of the order of €100 000 in LPG pre-cooled water to the electrical chillers per year. The hot water for the Paranal References to further lower its temperature to the Residencia is already heated with the desired level. It has not yet been decided exhaust gas from the gas turbine, but this Abott, D. 2010, Proc. IEEE, 98, 42 which of the two solutions will finally be system could be expanded also to the Pickard, W. F. et al. 2012, Proc. IEEE, 100, 317 chosen. A detailed engineering study is container camp and later be upgraded to Weilenmann, U. et al. 2010, SPIE, 7737, 77371Y required to explore these options. a solar heating system. Waste water treatment and recycling is another exam- Links A collecting area of approximately 1500 ple where costs and resources could be 1 square metres is required for the solar saved. OECD: http://www.oecd-ilibrary.org/economics/ country-statistical-profile-chile_20752288-table-chl collectors, which would require an area of 2 International Energy Agency: http://www.iea.org/ 2000 square metres of land. A suitable On the smaller scale there are all the stats/electricitydata.asp?COUNTRY_CODE=CL place has been identified in the vicinity of desktop computers, screens and printers 3 Absorption Chillers: http://www.solair-project. the present satellite antenna (see Figure 4). that could either be switched off or put eu/143.0.html

The Messenger 148 – June 2012 41 Astronomical News

Report on the ESO/IAG/USP Workshop Circumstellar Dynamics at High Resolution

held at Foz do Iguaçu, Paraná State, Brazil, 27 February–2 March 2012

Thomas Rivinius1 Alex Carciofi 2 Dietrich Baade1

1 ESO 2 Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Brazil

The workshop was jointly sponsored by ESO, the Brazilian National and São Paulo state agencies CAPES and FAPESP, and the University of São Paulo. Nearly 70 participants gathered to discuss the immediate surround- ings of stars, mostly those more massive and hotter than the Sun. The venue, near the spectacular Iguaçu waterfalls, and topic proved to be well chosen to attract a balanced crowd: Figure 1. The conference group photo taken against converge to a common physical basis, about one third of the participants the splendid backdrop of the Iguaçu Falls. namely that of a geometrically thin disc in came from each of Brazil, other ESO Keplerian rotation that is driven by viscos- member states and Chile, and ESO non- ity (talks by J. Bjorkman and C. Jones). member states. Circumstellar discs and outflows This provided a most valuable common baseline for further exploration, as was The meeting started with two oral ses- shown by D. M. Faes for an interfero The dynamics of circumstellar envelopes sions on circumstellar discs and their metric phase effect so far not consid- is an active research frontier that has outflows. The first, focused on obser ered, and by R. Halonen concerning the benefited greatly from the advent of high- vations, was opened by reviews on discs role of polarimetry in revealing the disc resolution observational techniques in and their properties during various evo structure. X. Haubois extended the theo- the spectral and spatial domains. The lutionary phases by R. Oudmaijer and by retical understanding of Be star discs into diverse and complex circumstellar envi- introductions to, and results from, various the temporal domain, while A. Granada ronments revealed by these observational observing techniques, such as pola approached the issue from a different techniques are particularly evident near rimetry (presentation by A.M. Magalhães) direction by investigating how Be stars fit hot, high-mass, stars, where stellar radia- and both amplitude and intensity inter into the current understanding of stellar tion plays a large, if not crucial, role ferometry (by P. Nuñez and F. Millour). A. evolution. in continuously shaping the immediate Kaufer showed the late B supergiant environment. Rigel to be a particularly interesting case, exhibiting a cyclically recurring large- δ Sco and Be stars as laboratories for Circumstellar structures have not only scale circumstellar structure. In two con- circumstellar disc physics been resolved spatially, but also have tributions exploring the fate of circum been followed over characteristic time- stellar ejecta of less massive stars over In July 2011, the highly eccentric binary δ scales of their variation. This dynamical longer timescales, R. de la Reza won- Sco went through periastron passage, evolution has been modelled for discs dered why no ejection shells had yet been more than ten years after the previous and winds: we are now directly observing discovered around lithium-rich giants, one. The previous periastron event and and measuring the consequence of the and T. Ueta introduced the Herschel Plan- the evolution since, summarised by A. physical mechanisms operating within etary Nebula Survey. Miroshnichenko, sparked significant inter- the circumstellar environments. As a est in the object, as δ Sco seems to result, current observing facilities, not The second session then concentrated have started to build up a circumstellar least the ones operated by ESO, have on the theory addressing the observa- Be star disc around that time. Therefore, allowed the field to progress from a static tional phenomena. Magnetohydro the 2011 periastron passage was antici- picture of the circumstellar environment dynamic wind models were presented in pated to clarify if and how the periastron towards understanding its dynamics detail by A. ud-Doula, a topic picked has any connection to mass ejection and the physical processes dominating up frequently in later contributions. One and disc formation. On this occasion the the dynamics. of the most interesting aspects of the disc around the primary was fully devel- current state-of-the-art disc modelling is oped, so monitoring its response to the that the Be star models have begun to passage of the secondary was another

42 The Messenger 148 – June 2012 1 2.0 ) as

(m 0

ormalised) 1.5 pos (n

Δ λ F

1.0 –1

–400 –200 0 200 400 –300 –200 –100 0 100 200 300 Velocity (km/s) Velocity (km/s)

Figure 2. Spectroastrometric observations of β CMi. Japan, in 2005, is probably among the Massive star formation out of a dynamic The data are compared to HDUST models featuring most significant achievements of this environment angular momentum and Keplerian rotation (blue and red respectively). The combination of high spectral workshop, given that this issue has been resolution and sub-milliarcsecond spatial precision debated for decades, sometimes quite The session on star formation began with constrain the disc kinematics. Only the Keplerian controversially. an unusual setup. Since M. Krumholz model can simultaneously recreate the observed line could not be present in Iguaçu, he profile (left) and the spectroastrometric signature (right). From Wheelwright et al. 2012, MNRAS 423, agreed to give his talk on the theory of L11. Dynamics of circumstellar material and massive star formation via Skype on tidal interactions in hot binaries one screen, while the slides were shown on the other. This ad hoc teleconfer attractive opportunity in 2011. Observa- The δ Sco periastron found significant encing solution worked flawlessly, and tions of the 2011 periastron and their attention within the Be star community. the audience was rewarded with a very preliminary interpretations were presented But the fact that η Carina is an eccentric interesting contribution on collapsing by S. Štefl in the oral session and by binary, interacting in many ways, has molecular clouds. L. Ellerbroek provided some posters. certainly impacted the community still insights into an alternative scenario of more deeply. Consequently, this star and the accretion history of an intermediate- High angular observations of Be stars, other Luminous Blue Variables (LBVs) mass young stellar object. at the Very Large Telescope Inter- featured prominently in this section, ferometer (VLTI) as well as other interfero- beginning with a review given by J. Groh Interferometry is a major driver in this metric facilities, and their implications on interferometric data and a contribution field, with baselines ranging from typical were reviewed by Ph. Stee, while the by Z. Abraham on radio observations. single-dish diameters (aperture mask- dynamical theory of Be discs in binaries The question whether possibly all LBVs ing, talk by S. Lacour) via long optical was presented by A. Okazaki. Obser with giant eruptions might be binaries baseline interferometry like the VLTI vations of the latter were shown by R. was raised by C. Martayan. (presentation by W.J. de Wit) to the kilo- Mennickent, pointing out the existence of metre-scale baselines in the submilli hundreds of peculiar double periodic Moving away from these most extreme metre range that will be offered by ALMA binaries, in which the non-orbital photo- cases, D. Cohen, S.P. Owocki, and J. (presentation by N. Evans). metric period, originating from a circum- Sundqvist presented the recent develop- stellar disc, is typically longer than the ments of the theory of radiatively driven orbital one by a factor of about twenty. stellar winds on a broader scale, ranging Magnetospheres of hot stars from X-rays as shock diagnostics, via The presentation by H. Wheelwright, structural questions in general, to tempo- The observational facts about magneti- comparing observations of the disc of ral variability. The remainder of the ses- cally-governed environments of hot stars β CMi to kinematic models of the cir sion was devoted to more individual top- were introduced by E. Alecian, and com- cumstellar velocity field, reinforced the ics, in particular the interferometric study plemented by R. Townsend, providing an understanding presented already in of a B[e] star by M. Borges Fernandes, overview of theoretical insights into the the previous sessions and by Stee: Be the circumstellar structure of a Be X-ray interplay between rotation, magnetic field star discs are in Keplerian rotation. binary during a giant outburst by Y. and stellar wind. Detailed examples were Consensus on this controversial result, Moritani and the modelling of [WCE] stars presented by V. Petit and A. Carciofi; growing since a meeting in Sapporo, by G. Keller. T. Rivinius argued that a sufficient num-

The Messenger 148 – June 2012 43 Astronomical News

ber of such objects are currently known reminding the participants of the pro- bles us to publish printed proceedings in to permit statistical analysis, and possibly gress made and presented at the meet- full colour, which will appear in the con- to postulate these objects as constituting ing, but putting emphasis as well on the ference series of the Astronomical Soci- a class of magnetic hot stars. Many of work left to be done. ety of the Pacific, edited by A. Carciofi these newly found magnetic stars were and T. Rivinius. provided by the MiMeS survey, summa- A public talk by D. Baade, translated rised by G. Wade, which finds a magnetic simultaneously from English into Portu- field incidence of typically 10% in mas- guese, on ESO’s Extremely Large Tele- Acknowledgements sive stars, very similar to lower-mass (but scope and the quest for extraterrestrial We are very grateful for the enthusiastic work of both still non-convective) stars. The only strik- life was attended by members of the Pólo the scientific and local organising committees. The ing exception are the Be stars, a class Astronômico, a large and active group meeting benefitted greatly from the organising sup- for which not a single magnetic member of amateur astronomers, as well as the port of Maria Eugenia Gomez and Marketka Šteflova. has been found. This result has the conference participants. A Star Party, We thank the Pólo Astronômico for their enthusiasm and the staff of the Rafain Palace Hotel for their potential to settle another longstanding prepared by the Pólo Astronômico for assistance. debate, namely what role, if any, mag- after that talk unfortunately could not be netic fields play in the formation of discs held due to bad weather. The excursions around Be stars. to the Brazilian and Argentinean sides Links of the Iguaçu waterfalls were as spectac- 1 New seven wonders of nature: http://www.n7w.com ular as expected for a visit to one of the Closing talks new seven wonders of nature1.

The final talk of the meeting was given by The generous sponsorship not only by D. Baade, summarising the contributions, ESO but also by Brazilian agencies ena-

Report on the Workshop Observing Planetary Systems II

held at ESO, Vitacura, Chile, 5–8 March 2012

Christophe Dumas1 Michael Sterzik1 Claudio Melo1 Ralf Siebenmorgen1 Julien Girard1 David Mouillet 2

1 ESO 2 Observatoire de Grenoble, Switzerland

This second edition of the Observing Planetary Systems workshop was aimed at bringing together the two communities of Solar System and exoplanetary system scientists to review the recent progress made in our understanding of the formation of the Solar System and its early chemistry, and how this picture fits with our current knowledge of the formation and evolution of planetary systems in general. Figure 1. The workshop poster.

44 The Messenger 148 – June 2012 Motivation second edition was to provide a real- ple of how massive planets create gaps time video link of the presentations in a within the disc, impacting the evolution Exactly five years after our successful separate location, adjacent to the main of the disc/gas material as well as the Observing Planetary Systems work- conference room. People (registered and formation of other planetary embryos shop held in March 2007 (see Sterzik & non-registered participants) could thus within the same system. The signature of Dumas, 2007), we again brought the follow the discussions while working in forsterite at 69 μm turns out to be two communities of Solar System and groups, in the nice and comfortable envi- another powerful tracer of gaps in discs, extraplanetary system scientists together ronment of the ESO-Chile library. This and hence a tracer of planet formation at the ESO/Vitacura headquarters in service was highly appreciated by the history. Santiago de Chile for the second edition meeting participants. of this conference (OPS II). The focus was Competing processes of accretion similar to five years ago, i.e. to review, In order to take advantage of the pres- were described (talk by H. Schlichting) from an observational standpoint, our ence and interest of many international throughout their evolution from small- progress in understanding the processes experts, the conference was immedi- scale bodies to planetesimals and plan- involved in planetary formation and the ately followed by a single-day workshop ets. Runaway growth explains well application of the knowledge of the Solar focused on high-contrast imaging the current mass and distribution within System to help constrain our picture of and spectroscopy of planetary systems, the Kuiper Belt of the Solar System, extrasolar systems in general (see the to review the latest progress made in as well as the measured mass ratio for meeting poster in Figure 1). observing techniques, technology and Kuiper-Belt binaries. The rest of the first data-reduction. More information about afternoon was used to discuss: the cru- The conference was very well attended, this workshop can be found on its web- cial role of multi-wavelength observations with more than 100 registered partici- site2 and it is briefly described at the end of discs; and the need for higher spatial pants, and the limited capacity of our of this report. resolution to improve the current models meeting room unfortunately forced us to of disc evolution and planetary formation decline some interesting contributions. (presentation by S. Wolf). Participants to this workshop repre- Scientific highlights sented 15 countries: Brazil, Argentina The second and third days were dedi- and Chile in South America, Canada and The linear progression offered over the cated to models and observations of exo- USA in North America, and the rest of four days of this workshop, from the planetary systems. It contained an inter- the participants coming from ten different study of the early stages of planetary esting series of presentations on how European countries, with a significant accretion to the formation of planetary early planetary dynamics (e.g., through representation from Spain, United bodies, their dynamical interaction planet resonances and inclined orbits) is Kingdom, France and Germany. Out of and physical composition, paved the way able to shape the final distribution (in 107 participants, 27 were graduate stu- for the final sessions. Here observing distance, and mass) of exoplanets seen dents, which provided a great opportu- programmes aimed at characterising the today in mature systems (talks by nity to update our young researchers on atmospheres of exoplanets, demon C. Terquem, Y. Alibert, and A. Morbidelli). the latest developments in this highly strating techniques to search for bio- Interestingly, planets accessible to direct dynamic field. The meeting was held over markers and describing the potential imaging are still hard to find. This is a four full days, covering the main aspects breakthroughs expected from the latest/ consistent result of all ongoing major of planetary formation and characterisa- future ground- and space-based planet- adaptive optics (AO) surveys, even after tion within four distinct sessions: “Plane- finding machines were all discussed. the tremendous progress made over the tary discs and the first Myrs of planetary past few years in lowering the detection formation”, “Nature and orbits of plane- The morning of the first day was dedi- limits via improved observing techniques tary bodies: Models and Observations”, cated to far-infrared and submillimetre (as exemplified by presentations by B. “Planetary atmospheres and bio-markers”, observations of stars surrounded by Biller, R. Galicher, E. Nielsen, M. Bonavita and “Future planet-finders and novel discs in their various stages of formation, and J. Rameau). technologies”. Contributions were made from directly after collapse to photo- by a combination of invited talks (11 dif- evaporating and debris discs. The early Precision radial velocity surveys in ferent invited speakers), contributed pres- results of Herschel programmes to combination with transit observing cam- entations (44) and posters (38 in total). study disc properties, and the distribution paigns remain the main sources for and evolution of the dust/gas ratio were harvesting the population of inner planets We opted again for a prompt release of described (by W. Dent and G. Meeus), efficiently, allowing derivation of robust the presentation material rather than emphasising the need for improved evo- physical and statistical properties (talks having printed proceedings at a later lutionary models and access to high- by D. Queloz and M. Gillon). The stage. The oral contributions were also resolution images (as presented by β Pic system is a showcase of how ESO’s filmed with the consent of each author L. Testi). Some objects like TCha (talks by top-class instrumentation has led to and all this material (PDF and videos) is N. Evans and N. Huelamo) are exciting the characterisation of disc morphology available on the conference website1. targets to further constrain planet for and the first image of the giant planet One of the innovations made during this mation models as they are a clear exam- embedded within it (presentation by

The Messenger 148 – June 2012 45 Astronomical News Dumas C. et al., Report on the Workshop “Observing Planetary Systems II”

A.-M. Lagrange). Early (and already abun- In the same way that this second edition talks by A. Vigan and J. Girard). Finally, dant) results of the TRAPPIST experi- saw a surge in results presented from several presentations were given on inter- ment were provided (by E. Jehin), both on transit observations and very encourag- ferometric techniques based on diluted the study of comets (the most primordial ing prospects from a future astrobio facilities (by J.-P. Berge and D. Rouan) or objects in the Solar System) and in the logical characterisation of exoplanets, we Fizeau-like (from P. Tuthill and F. Patru). search and characterisation, via transits, can expect the next and third edition of exoplanets. The role of water in plane- to contain an increased number of contri- The very friendly and informal atmos- tary formation was also presented (talk by butions coming from ALMA and the phere of this workshop favoured D. Jewitt), not only regarding its ability to first extreme-AO planet finders (e.g., constructive discussions among the develop life, but also from the perspective SPHERE). These future facilities, added 70 attendees (most of whom were of what we can learn from the study to the continuous improvements made by also OPSII participants). We thank the of comets, and other pristine objects like radial velocity and other techniques, will ESO Office for Science, who provided Trans-Neptunian Objects, on the early no doubt dramatically shake up our vision the lunch in the park and all the coffee thermo-chemical processes undergone and understanding of the formation of and cheese breaks! This first edition since the formation of the Solar System. exoplanetary systems, their diversity and of HConIS, extended further the last ses- suitability to develop extraterrestrial life, sion of the OPSII meeting and was in The last day of the meeting was first while contributing to a deeper under- a way complementary to the “In the Spirit dedicated to astrobiology, and how the standing of the particular place held by of Lyot” conferences held in 2007 and study of Earthshine can provide a bench- the Solar System. 2010, bringing together high-contrast mark when searching for signatures of observers and instrumentation special- life elsewhere in the Universe (presenta- ists. All presentations and video stream- tion by E. Palle and M. Sterzik). The sci- ing of the presentations can be found entific promise of future planet-finding High Contrast Imaging and Spectroscopy online2. instruments soon to be installed on large Workshop (HConIS) ground-based telescopes is considerable, but the technological challenges still Immediately following the Observing Acknowledgements significant (as presented by D. Mouillet). Planetary Systems II conference, this We would like to thank ESO for allocating the finan- The ground-based effort will be comple- one-day workshop focused on high cial support for this workshop, and all the people mented by space missions like EchO contrast imaging and spectroscopy tech- who made this venue so pleasant, in particular and Plato to push even further the limits niques. ESO experts Julien Girard and Maria-Eugenia Gomez, our librarian who acted as of our understanding on how planets Dimitri Mawet moderated no less than workshop secretary, Paulina Jiron from the Office for Science, and the ESO-Chile administration for the form, why they are so diverse in size, 15 talks, which covered many aspects of excellent logistic support received. orbit and composition, and ultimately this exciting field. The morning session what fraction of planets harbouring life started with a science-oriented talk about could be detected from their atmospheric the spectral properties of β Pictoris b References signatures. (by M. Bonnefoy), followed by back-to- Sterzik, M. & Dumas, C. 2007, The Messenger, back presentations on the development 128, 72 status and schedule of planet-finders: Prospects the ESO SPHERE instrument (by D. Links Mouillet) and the Gemini Planet Imager The five-year period observed between (GPI), by M. Hartung. Additional contri 1 OPSII conference web site: the two first editions of this meeting butions followed on novel data-process- http://www.eso.org/sci/meetings/2012/OPSII.html 2 appears to be an adequate frequency to ing concepts making extensive use of HConIS workshop webpage: http://www.sc.eso.org/~jgirard/hconis keep the community up to date on the focal plane wavefront sensing in order to latest developments made in the discov- suppress quasi-static aberrations (talks ery of exoplanetary systems and our by R. Galicher and M. Kenworthy). Coro- understanding of their extraordinary nagraphic techniques for ground and diversity (with respect to their dynamical space missions were also reviewed aspects, the nature of their bodies and extensively (by D. Mawet, F.-Y. Bourget the mechanisms involved in their forma- and A. Boccaletti), as well as new tion). spectroscopic follow-up applications (in

46 The Messenger 148 – June 2012 Astronomical News

The ALMA Regional Centre in the Czech Republic and the ALMA Winter School in Prague

Bartosz Dąbrowski1 Marian Karlický1 P. Suchan P.

1 Astronomical Institute, Academy of Sciences of the Czech Republic, Ondřejov, Czech Republic

The scope of the work of the Atacama Large Millimeter/submillimeter Array (ALMA) Regional Centre in the Czech Republic is briefly outlined and a short report is presented on the recent Winter School held in Prague.

The Atacama Large Millimeter/submil limeter Array (ALMA) is under construction on the Chajnantor plateau in Chile and will consist of up to 66 antennas to observe in the frequency range from 30 GHz to 950 GHz, with very high sen Figure 1. The participants of the ALMA Winter 3. To reduce the solar electromagnetic sitivity and angular resolution. ALMA School in Prague in front of the entrance of the flux reflected to the antenna focus, it Astronomical Institute. is an international collaboration between will be very useful to scatter the visible/ Europe, East Asia, North America and infrared part of the spectrum by milling Chile. Astronomers from the different Our node is to be formed as a consortium the surface of the antennas. participating countries will interact with of the Astronomical Institute, Academy of 4. ALMA can directly measure tempera- ALMA via ALMA Regional Centres (ARCs). Sciences of the Czech Republic (ASCR) ture maps in the chromosphere. For In Europe, the main Regional Centre is and the Institute of Chemical Technology this purpose a precise calibration tech- located at ESO Garching and seven ARC in Prague, with further cooperation with nique is necessary. nodes are spread over the continent. the Charles University in Prague and the 5. For transient phenomena such as Masaryk University in Brno. solar flares, a flexible communication The Czech ARC node should provide protocol between scientists and regional support to applicants from coun- observing staff regarding observing tries of the Central and Eastern European ALMA and solar research targets is necessary. In proposals for region, e.g., from Poland, Slovakia, flare observations, it would be very Hungary, etc., that are not yet ESO mem- In Europe the Czech ARC node is the difficult to specify the observing tar- bers, and to Czech ALMA users. In par- only one devoted to solar physics. For gets in advance. ticular it will provide the following ser- solar research it is important to know vices: the limitations of ALMA and the require- Since the observing capabilities of ALMA 1) scientific and technical support to ments for solar observations: are so advanced, involvement of the ALMA users in the fields that are not 1. The field of view (FoV) of ALMA is solar community is highly desirable. To

yet covered, or are covered only rather small (21 arcseconds × λmm). encourage potential observers, the new partially, by other existing European For a detailed study of the “quiet” chro- Czech ARC node is being built under ARC nodes, and especially: (i) solar mosphere for example, this FoV is the supervision of ESO. Although we are and (extra)galactic astrophysics, (ii) sufficient. However, for phenomena in fully aware of the problems that are laboratory measurements of molecular which global effects are important specific to solar observations (small field spectral lines; (e.g., in solar flares), it would be desira- of view, strong radio flux, calibration 2) observation planning and data quality ble to increase the FoV, e.g., by an and so on), we hope that advanced OTF checking; observing technique called “on-the-fly” mapping and calibration techniques will 3) data storage and processing and (OTF). overcome these difficulties. ALMA has data reduction using CASA (Common 2. Compared with other astrophysical the potential for new insights and new Astronomy Software Applications radio sources (e.g., molecular clouds, discoveries, especially in a mostly unex- package, which is used to process galaxies) the solar radio flux is very plored wavelength range, making it highly both interferometric and single-dish strong and the ALMA detectors are desirable for solar research. More infor- data from ALMA). very sensitive. Therefore, for solar mation about solar research with ALMA observations an appropriate attenua- can be found in Karlický et al. (2011). tion of the signal is necessary.

The Messenger 148 – June 2012 47 Astronomical News

ALMA Winter School in Prague lar spectroscopy, CASA and the AOT Around 20 people from Croatia, the (ALMA Observing Tool). The AOT is the Czech Republic, the Netherlands, Poland The purpose of this two-day Winter tool used for the preparation and sub and the United Kingdom participated in School, which took place at the Astro- mission of proposals for ALMA. We fin- our ALMA Winter School. Invited speak- nomical Institute of the Academy of ished the day with practical exercises ers at the School were Dirk Petry and Sciences in Prague, was to prepare the using the AOT. Andy Biggs, both from ESO. European astronomical community for ALMA Early Science operations in The second day was mainly devoted to Cycle 1, which is expected to start in practical exercises with the CASA pack- Acknowledgements January 2013. age. To learn the CASA package we used We would like to express many thanks to Paola science verification data for the M100 Andreani, Dirk Petry and Andy Biggs (from the ALMA The first day was devoted to theoretical spiral galaxy. Also examples of proposals Regional Centre in Garching) for their help with our issues related to ALMA. At the beginning were presented and the submission pro- ALMA Winter School. the ALMA project was presented with cess was explained. In addition a lecture particular focus on the role of the Czech on solar research with ALMA was given. References ARC node. During the day we had lectures about radio interferometry, molecu- Karlický, M. et al. 2011, Solar Phys., 268, 165

Volunteer Outreach Activities at ESO Chile

The ESO-Chile Outreach Volunteer Introduction Estrellas en las Escuelas Team1 * The Chilean public has been aware of The study of astronomy and the Universe Chile’s extraordinary dark-sky treasures is part of any school programme and 1 ESO for a long time. Discoveries and upcom- appears at different stages in a pupil’s ing new telescope projects are often career. Several national and local initi reported in the press and interest in the atives in Chile have been set up to sup- ESO staff in Chile are often asked to achievements of astronomers and engi- port both pupils and teachers in the disseminate astronomical knowledge neers is steadily growing. But astronomy development of teaching activities in sci- to schools and to the general public. is more than scientific publications and ence. One of the most renowned pro- A significant number of volunteers are their accompanying press releases: it is grammes, called Enseñanza de las Cien- now involved in these activities and the a wonderful educational tool at each cias Basada en la Indagación (ECBI), is most recent projects in low-income stage in life. It can often offer uncharted the result of the joint efforts of the Chilean schools and neighbourhoods are paths to the discovery of essential con- Academy of Science, the Department described and possible perspectives cepts in physics and mathematics, but of Medicine of the Universidad de Chile discussed. also more generally to the development and the Ministry of Education (with finan- of scientific reasoning based on obser cial support from the European Union). vation and experimentation. Its primary goal is to reinforce children’s capability to establish scientific reasoning ESO staff in Chile are often approached based on experiments. The ECBI pro- to spread astronomical knowledge to gramme, when funding permits, already schools and the general public. In recent helps active elementary school teachers years some of these initiatives have in the teaching of science. Since astron- * Daniela Barria, Amelia Bayo, Jean-Philippe. Berger, grown and have involved a significant omy is not always a priority, volunteers Mauricio Carrasco, John Carter, Florian Gourgeot, number of volunteers. We report on the from ESO have been approached to Matias Jones, Guillermo Manjarrez, Sergio Martin, most recent developments in low-income develop pedagogical activities with Suzanna Randall, Myriam Rodrigues, Valentina schools and neighbourhoods in order teachers and pupils, under the supervi- Rodriguez, Ruben Sanchez-Jansen, Fernando Selman, Jonathan Smoker, Linda Schmidtobreick, to “democratise the sky”, and also dis- sion of the ECBI executive director (P. Joachim Vanderbeke, Maja Vuckovic, Jeff Wagg cuss various aspects of these activities. Reyes) and with the collaboration of the

48 The Messenger 148 – June 2012 Figure 1. Photographs of schoolchildren and parents participating in the Viaje a las Estrellas activities: queuing to look through the telescope (upper left); learn- ing about the planets (upper right); making models of the planets (lower left); telescope viewing of the night sky (lower right).

Municipalidad de Lo Prado (represented brought telescopes and a planetarium. housing project development. Their pro- by S. Huiaquiñir and A. Herrera). These events attracted not only pupils jects include not only the building of and their parents from the two schools, housing, neighborhood clubs and librar- The Estrellas en las Escuelas activities but also from neighbouring schools ies, but also provide community coor all began with a series of lectures for which was one of the main goals of the dination to promote responsibility for the 12 teachers from different schools. The directors. It was particularly moving to improvement of the social and cultural lectures were designed to include prac see people of all ages lining up in front of life. Our group of volunteers has per- tical activities in the classroom and the telescopes to discover the Moon, formed several demonstrations using the concluded with a visit to the Universidad Jupiter and Venus. All parties concluded stars and the Universe as the main Metropolitana de Ciencias de la Edu- that these events should be expanded subjects (see the upper image on the catión (UMCE) telescope, thanks to the to more schools and the representatives Astronomical News section page, p. 38). help of Prof. L. Barrera. Following some of the municipal council assured us they These activities range from telescope excellent contacts with some school would provide financial support to viewing of the planets and the Moon to directors, two Noche de las Estrellas develop them as a pedagogical tool. magic shows, ALMA antenna model (observing nights) were organised in two building, pavement art, rocket launching, schools — Escuela Poeta Pablo Neruda etc. The volunteers for this project were and Escuela Poeta Vicente Huidobro. Viaje a las Estrellas basically the same as for the Estrellas en The ESO team, with the support of the las Escuelas project, and this allowed us Office for Science and ePOD, presented A group of enthusiastic Vitacura fellows, to get a better feeling for which activities several stands, including a magic per students, and staff have been bringing are appropriate for which age groups. formance, rocket and satellite building, an the world of astronomy to social housing In particular, the age range of the children inflatable planetarium, Solar System communities in Renca in a programme targeted in this programme is quite large, paintings, Moon–Earth exploration and named Viaje a las Estrellas (literally, an from approximately 4 to 15 years, to- telescope observations (see Figure 1). effort to democratise the sky). These gether with many interested parents. Students from the Pontificia Universidad activities have been coordinated by Fun- This activity was supported by one of the de Chile and representatives of the ama- dación Gestión Vivienda, a private non- community organisations, Biblioteca teur group Telescoperos joined us and profit corporation dedicated to social Mujer de Esfuerzo.

The Messenger 148 – June 2012 49 Astronomical News

The programmes are complementary: we encounter. ESO has already agreed colleagues from other institutes in Chile Estrellas en las Escuelas targets the to fund the purchase of one telescope, and abroad: D. Carrasco, C. Infante, pupils and teachers (with the teachers which will be more than welcome. Work- C. Sifón at Pontificia Universidad Católica providing a huge capacity to pass on ing together with higher authorities, de Chile; C. Tappert at Universidad de information to others) in an academic whether local (schools, associations) or Valparaiso; R. Zepeda, a member of the environment, while Viaje a las Estrellas national (the education ministry) has Telescoperos group that provided the focuses on the families, bringing science proved to be a powerful way to make telescopes; Prof. L. Barrera at Universidad to the communities as another route to sure we meet the needs of the different Metropolitana de Ciencias de la Educa the education of children. communities. The challenge is now ción; N. Huelamo (Centro de Astro to keep up the momentum while continu- biologica [CAB], Madrid); and A. Galenne ing with our own research and opera- (Observatoire de Meudon, Paris). Challenges and perspectives tional tasks and to encourage new volunteers to get involved in order to assure The different activities have been a the longevity of the effort. Acknowledgements tremendous success and the ESO-Chile We warmly thank the ESO-Chile Office for Science volunteers will no doubt be called upon (in particular the great support from Michael West, once again in 2012. Preparations for The team Paulina Jiron and Veronica Hormazabal), ePOD- these activities have also been a very Chile (particularly Valentina Rodriguez), Gonzalo nice way to get to know our colleagues in The ESO-Chile outreach volunteer team Argandoña, Philippe Gitton, the ECBI team led by P. Reyes, the Municipalidad de Lo Prado and Fun- a different context. The focus will now consists of all those listed above and dación Gestión Vivienda. be to develop our palette of activities and is growing fast. In addition, we have been to adapt them to the different audiences accompanied during these activities by

Inspiring Young Brazilian Astronomers at the La Silla Observatory

Jorge Meléndez1 teaching this course in March 2012 at the related instrumentation. Getting close to Astronomy Department of the Institute of the HARPS spectrograph, the very pre- Astronomy, Geophysics and Atmospheric cise instrument for planet hunting that 1 Astronomy Department, Instituto de Sciences (IAG) at USP, and thought it was being employed for the Large Pro- Astronomia, Geofísica e Ciências would be important for the students to gramme, was one of the highlights of Atmosféricas, Universidade de São visit a world-class facility such as La Silla. the trip. The observations for my Large Paulo, Brazil Since I had been allocated time in late Programme were being undertaken by April 2012 for my ESO Large Programme Luca Casagrande, a team member of for a search for planets around solar twin the collaboration. He explained to the Eight astronomy students from the stars, I asked the Director of the Paranal students how the observations are per- University of São Paulo in Brazil had the and La Silla Observatories, Andreas formed. Thanks to the HARPS pipeline invaluable experience of visiting the Kaufer, if the IAG/USP students could join that reduces the spectra in a few sec- La Silla Observatory from 27–30 April my observing run and get to know the onds, the students could discover for 2012. This visit proved an excellent telescopes at La Silla. I was delighted themselves the most promising candi- opportunity to develop stronger links when this exceptional visit was approved. dates for hosting planets around our between the new generation of Brazilian sample of solar twins. astronomers and ESO. We were warmly welcomed at La Silla. All the staff and most of the astronomers The students enjoyed all aspects of our observing there were very helpful with all visit, experiencing for themselves the life The group of astronomy graduate stu- aspects of our trip. We visited the ESO of observational astronomers. During the dents was led by the author as part of the 3.6-metre, the 3.58-metre New Technol- first half of the visit the weather was not activities for the graduate course in ogy Telescope (NTT) and MPG/ESO 2.2- very friendly, but during the second half Observational Astrophysics at the Univer- metre telescopes and were given detailed the skies cleared. Although it was a pri sidade de São Paulo (USP). I started explanations of the telescopes and their vilege to observe with large telescopes,

50 The Messenger 148 – June 2012 it was also wonderful to see, with the Figure 1. The visiting naked eye, the beauty of the night sky, students in front of the 3.58-metre NTT tele- the magnificent Milky Way and its dark scope. From left to right: clouds, our neighbouring galaxy, the student Ana Molina, Large Magellanic Cloud, and some stellar Prof. Jorge Meléndez, students Patricia Martins clusters with the help of binoculars. Fernando de Sousa Mello de Novais, Miguel Paez, During the day it was a magical experi- Nathália Cibirka, ence to witness the vivid colours of the Fernando de Sousa sky and their contrast with the white Mello, Viviane Salvador domes and the desert mountains, espe- Alves, Marcelo Tucci Maia and Andressa Silva cially at sunset. The contact with other Ferreira. astronomers and students working at La Silla has surely widened the astronomical vision of the student visitors. The visit to La Silla ended with two other memorable experiences. We hiked around the La Silla site in search of petroglyphs. This proved to be a challenging but exciting experience, and we success- fully found the ancient petroglyphs. Finally, during our last night at La Silla, the students were awakened by a 5.5 magnitude earthquake with an epi- centre close to the city of La Serena.

Taking advantage of this rare opportunity to visit La Silla, the group also made a Figure 2. The Brazilian one-day trip to other nearby observato- graduate students pose in front of the, now ries while they were based in La Serena. de-commissioned, The visit to La Silla was a fantastic and 15-metre SEST submilli- unforgettable experience for the stu- metre telescope, with dents. They have learned a lot, not only Prof. Jorge Meléndez on the left. about telescopes and instruments, but also about themselves, and that dreams can come true. This trip will surely inspire them for many years to come. Molina Ana

Acknowledgements

We would like to thank: Peter Sinclaire, who showed us around the different telescopes and their instrumentation; Luis Wendegass for his detailed explanations about the petroglyph trail; Luca Casagrande, who was observing with HARPS at the 3.6-metre; as well as the other astronomers and ESO staff for their kind help. We warmly thank Andreas Kaufer for promptly authorising the visit to La Silla and for providing free local transportation and accommodation. Finally, we are most grateful for the prompt financial support provided by the Vice Dean of Graduate studies at USP (Prof. Dr. Vahan Agopyan) and the Director of IAG/USP (Prof. Dr. Tércio Ambrizzi).

The Messenger 148 – June 2012 51 Astronomical News

Retirement of Klaus Banse

Pascal Ballester1 mented progress during the first decade hundreds of gigabytes of data on multi- Michèle Péron1 of development, during which time threaded architectures. Klaus and the MIDAS team adapted the system from Fortran 77 to the C pro- A very well attended leaving party was 1 ESO gramming language, and from VAX/VMS held at ESO Headquarters on 3 May 2012 to a variety of Unix platforms, and later attended by the ESO Director General to Linux-based operating systems. By Tim de Zeeuw (see Figure 1), many col- On 30 April 2012, after 34 years of ser- the end of 1992, MIDAS had been distrib- leagues and members of the ESO swim- vice, Klaus Banse left ESO to enjoy a uted to 160 astronomical institutes in ming club, of which Klaus was a founding well-deserved retirement. Klaus joined 37 countries, and Klaus was in perma- member. We were honoured to present ESO in Geneva in December 1977, when nent contact with its many users, while Klaus with a book on the historical vistas ESO had only about 80 employees. He consolidating the system standard inter- of information handling in astronomy, was initially recruited to develop “algo- faces and the core display functionalities. signed by colleagues from Europe, the rithms for the astronomers”, but really The system remained the foundation USA and Canada, in recognition of his started his career at ESO by developing of data reduction processes for the VLT contributions to the international develop- control software for the ESO measuring first light in 1998 and for the first instrument of astronomical data reduction machines (Crane, 1979). ments of the VLT. A new architecture for systems (see Figure 2). We will not only the VLT pipelines was developed in 2000, miss Klaus’s technical skills but also In 1979, ESO began the planning and relying fully on C-based data reduction his congenial personality and his dedica- development of a new image processing chains, and in 2004, Klaus became the tion. We wish Klaus all the best for his system to fulfill increasing data analysis team leader of the ESO Common Pipeline retirement. and image processing needs, and Klaus Library remaining in this position until became the main architect of ESO- his retirement. Over his 34-year career at MIDAS (originally the Munich Image Dis- ESO, Klaus was a key resource in the References play Analysis System), first released field of astronomical data analysis, as Banse, K. et al. 1983, The Messenger, 31, 26 in 1982 (Banse et al., 1983). The MIDAS techniques in astronomy evolved from Crane, P. 1979, The Messenger, 19, 31 Memo column in The Messenger docu- scanning photographic plates to handling

Figure 1. The ESO Director General Tim de Zeeuw Figure 2. Klaus Banse enjoying the good wishes of offering Klaus Banse his hand in appreciation of colleagues in the book presented to him at his retire- Klaus’s many years of service to ESO. ment party.

52 The Messenger 148 – June 2012 Astronomical News

Staff at ESO

Alistair McPherson complete change of direction. Whilst looking for another career opportunity, As one of four boys brought up in I saw an advertisement for the job of Scotland, I was always the one with a VLT Infrared Survey Telescope (VISTA) screwdriver in my hand looking to project manager at the observatory in “fix” something. It seemed inevitable that Edinburgh. As I read the advert I realised my love of things mechanical would lead that I had the qualities and experience me into engineering and I did this by that they were looking for and applied. joining the army, attending Sandhurst The rest is history. and completing a degree in aeromechan- ical engineering. I then commanded I thoroughly enjoyed this appointment a number of units in the UK, Hong Kong and I learned a great deal about tele- and Germany — both helicopter sup- scopes and how the astronomy commu- port units and mechanical workshops — nity worked. This also gave me an intro- leading my soldiers on operations in duction into ESO and, of course, Paranal. Northern Ireland, the Gulf War and Bosnia. So, when I was no longer required on VISTA and there was an opportunity on As my career progressed I became more the European Extremely Large Tele- involved in procurement programmes, scope (E-ELT), I was pleased to come to initially as a member of a French, German Garching and join the team at the latter and UK project based in Paris and my part of phase B. last job in the army was as the programme manager for the Lynx helicopter fleet. I have had a varied, interesting and chal- In this job, I was responsible for all engi- lenging career both in the army and in with younger intelligent people. Maybe neering, maintenance and airworthiness the world of observatories. Although I still that keeps me young? issues, as well as the procurement of a barely scratch the surface of the astron- replacement fleet of some 100 helicopters. omy side of the work, I am fascinated and Many challenges lie ahead of us as we motivated by being at the frontline of move towards E-ELT construction, but as After my job with Lynx, which I really some pioneering engineering within the an organisation we can work together enjoyed for the variety of engineering, E-ELT project. I continue to enjoy the to achieve the completion of this vision. I leadership and politics, I made the challenges that we face and, according look forward to leading the team which decision to leave the army and seek a to my wife, I apparently enjoy working will deliver the reality of the E-ELT.

Fellows at ESO

Maja Vučković major advantage for photometrically and fall asleep there while watching the stars. spectroscopically variable objects as it I was mesmerised by the night sky, while I have been living in Santiago de Chile allows the various contributors to a spec- all her other grandchildren would safely and working as an ESO Fellow for two trum to be disentangled, which is one of be sleeping in their beds surrounded by years. Of that time I have spent about the hottest topics of my research at pre- their favourite toys. Even though it seems six months in the Atacama Desert at the sent. While in Santiago, apart from enjoy- that I have known what I wanted to do Paranal Observatory as a VLT support ing a “normal life”, I am trying to under- since my childhood, the road to where I astronomer. While on Paranal, I am also a stand what the hot subdwarf stars do. am now was anything but straightforward, Fellow responsible for X-shooter on Unit and it took many years. Telescope 2 (UT2), the unique echelle I was one of those children who dreamed spectrograph that can obtain a simulta- of becoming an astronomer when they Thirsty for knowledge during my under- neous spectrum from ultraviolet to near- were growing up. My grandma frequently graduate studies of astronomy at the infrared wavelengths (0.3–2.5 μm). This took me from the roof of our vacation University of Belgrade, my home town, I simultaneous wavelength coverage is a house in the mountains as I would often was totally taken by the observational

The Messenger 148 – June 2012 53 Astronomical News

astronomy course. The undergraduate telescope, for high-speed photometric studies at my university at the time were monitoring of rapidly pulsating subdwarf based mostly on following courses, pass- B (sdB) stars. As soon as the skies ing written and oral exams and at the had cleared, even if only very late in the time I didn’t have a clue what research night, I’d head off to the Fick Telescope; was all about. After the oral exam I went my friends still joke about the strong to my professor, Istvan Vince, and told correlation between the clear skies and him (more like complained) that I was my disappearance from every party! bored of just studying, solving problems and taking exams, and that I would like The research in asteroseismology of to do something! He gave me some stel- sdB stars, during my Masters studies at lar spectra to reduce. Soon after I found Iowa, mainly consisted of gathering, myself at an international conference analysing and interpreting photometric eagerly presenting a poster with my work data in white light. Through this study it and discussing the temperature sensitiv- became clear to me that the ultimate ity of Mn lines over dinner ... Now I know goal of any asteroseismological study — that is what research is about. can only be achieved with accurate pul- sation frequencies and an unambiguous However, my undergraduate studies identification of the oscillation modes. were interrupted by the difficult situation While I was writing up my thesis on in my country (Serbia). Torn by civil wars, Maja Vučković PG0014+067, an intriguing pulsating sdB decimated by sanctions, hyper-inflation star, Conny Aerts, the professor at the and finally NATO bombing, life took a scientists would use the Earth’s rotation Institute of Astronomy at the University of “parallel path” and I felt the need to con- — the biggest enemy of any asteroseis- Leuven, and the world’s leading expert tribute to humanity while living through a mologist — as a tool to obtain continuous on mode identification, came to our humanitarian catastrophe. I fully engaged 24-hour light curves in order to derive department to work with Steve. We dis- in activism and spent several years as the fundamental parameters of stars. The cussed my research over a few lunches, a volunteer in a non-governmental organ- headquarters were at Iowa State Univer- she saw my devotion to observing and, isation (NGO) taking care of and helping sity (ISU) and I contacted Steve Kawaler, in between the lines, gauged my nostal- refugees, mainly adolescent girls who the professor at the Department of gia for the cobbled streets of European had been traumatised by the war and the Physics and Astronomy and director at towns. Soon after she returned to bombing. In fact my first proposal was the time. He told me what I should do in Belgium, I received an offer to continue not in astronomy at all! It was for a Euro- order to enroll for graduate studies at my research on sdB stars with her in pean Union grant to foster the livelihood ISU. Several months later I had my fare- Leuven. The University of Leuven had so of girls who had suffered violence, by well party. much to offer: it is one of the oldest uni- founding centres in several towns of Ser- versities, is in the middle of Europe, they bia which would work to raise awareness, I arrived in Ames, Iowa in August 2001 make one of the best dark chocolates educate society, and improve integration, with my life packed in two suitcases, in the world, not to mention all the varie- while also serving as shelters. When the ready to start my graduate studies in ties of beer, AND I could continue study- situation in the country stabilised some- astrophysics. During my first day at the ing pulsating sdB stars!!! what, I decided it was time for me to con- ISU campus I met Steve, who opened tinue with my life. I asked myself yet again the door of science for me. He is one I arrived in Leuven in August 2005, with what it was that I wanted to do, and my of those professors who can transmit my life packed in two suitcases ready mind took me back to the very same roof his thrill for science, and stamina for to start my PhD. The Institute of Astron- of my grandma’s house ... it was clear research, to the student, while letting you omy (IvS) is a great place to work, the that I wanted to continue studying astro- struggle, but never fall. After a few months friendliness and the enthusiasm of all the physics! I was already observing at the 2.1-metre people there quickly made it into my telescope at the Kitt Peak National Ob new home. I still have that nostalgic look Asteroseismology, the relatively young servatory as one of the observing sites when I talk about it. Apart from offering branch of astronomy devoted to the for my first WET run. The more I learned me a comfortable research nest, it study of internal stellar structure on the about asteroseismology the more I was allowed me to fulfill my thirst for observ- basis of stellar vibrations, caught my enchanted by it — the fact that we can ing. The IvS has a 1.2-metre Mercator attention. While reading more I found out “look” into the interiors of stars by study- Telescope at one of the most beautiful about the Whole Earth Telescope (WET), ing their pulsations is still what keeps me European observing sites on La Palma in a worldwide network of cooperating astro- going. the Canary Islands and I spent at least nomical observatories linked together two months per year observing there. to obtain uninterrupted time-series meas- My strong observing interest resulted in Also, observing time is shared with urements of variable stars. The idea my adopting the small University Obser- the twin 1.2-metre Euler Telescope at sounded profound to me: that a group of vatory, equipped with a Fick 0.6-metre La Silla. I will never forget my first observ-

54 The Messenger 148 – June 2012 ing run at the Euler Telescope — it was Beware of your dreams, they may come my first encounter with the southern skies true! and with the desert. I can’t really tell which of the two made the stronger impact on me; but the feeling of peacefulness Giacomo Beccari and fulfillment I felt while observing there is the one I come back to whenever the The oldest memory I have of the stars inevitable question of a (somewhat lost) is of Ursa Major. When I was a child, dur- nomadic, modern-day astronomer “is this ing the summer holidays, I used to sit all worth it?” comes to my mind. on the strong shoulders of my father and spend time with him wandering along the While studying the origin and evolution beach at night watching the stars. The of hot sdB stars during my PhD, my constellation of Ursa Major was the only research interest naturally expanded into one that my father ever knew, but he studying close binary stellar evolution, used to show it to me every night, telling in particular post common envelope ejec- me fantastic stories.… That constellation tion systems. Once the PhD was de appeared to my eyes as the most beauti- fended, it was time to find a “real” job; I ful thing in the sky … and still does. guess for everyone this is a scary moment as all of a sudden you have to get out I was born in Verona some years ago. of your PhD “bubble” and begin your way I like to see myself moving around with a Giacomo Beccari through life. In the heat of my PhD party funny Veronese flavour permeating my a good friend, an ESO Fellow in Chile at personality: that strange mixture of roman- new scientific projects, new ideas, a few the time, started to convince me to apply ticism (Romeo and Juliet as it were), pas- kroketten, and knowing that science is for the very same job. One of his strong- sion and fanaticism (go to a soccer sta- much more than sitting at the desk in the est arguments was “you would love it”. dium in Verona on Sunday and you will office analysing data. He was right! understand), and South Tirolean rational- ism. I studied astronomy at the University I came to ESO as a fellow with the desire In April 2010 I arrived in Santiago, this of Bologna followed by a PhD in astron- to discover how a big astronomical ob time with my life packed into somewhat omy and informatics at the Astronomical servatory works, what’s behind it. In more than two suitcases. Again, starting Observatory of Teramo. I am proud of Garching I found a community of excel- another four-year life cycle, I moved to seeing myself as a disciple of the glorious lent scientists and an enthusiastic envi- a different continent, ready for my ESO Italian school of stellar astrophysics. Even ronment that triggered new collabora- Fellowship and the new challenges of life. if I do not know much about the constel- tions and ideas. I asked to be assigned lations, astronomy is for me, as for all the for my functional duty as support astron- During my last turno at Paranal, I was astronomers I have met so far, a passion. omer at the Very Large Telescope (VLT) sitting at the back of UT1 watching the To do a colour–magnitude diagram in Paranal. This experience has been sunset, something I usually do every day (affectionately called a CMD) can be ther- even more exciting than I thought. I will while observing there. It is also the point apeutic. As an example, I remember in always remember the first time I walked where the day and the night crew meet. 2010, when the Italian team was badly into the Control Room … UT1, UT2, But that day I was alone and my thoughts eliminated from the Football World Cup, I UT3, UT4… there is no cause for alarm … took me far far away, back to one of my was so depressed that I went to my office VST, VISTA, VLTI … mamma mia! Then high school days. The surprised face of and downloaded some images of 47Tuc walking back … interferometry, wide-field my high school professor appeared in my from the Hubble Space Telescope (HST) multi-band surveys, high resolution adap- mind when I had told him that I would archive. I analysed the data and it was tive optics imaging, multifibre and single study astronomy. He wanted to challenge only after I saw the beautiful cluster’s object spectroscopy at almost all wave- my choice and simply asked “But why?”, main sequence in the CMD that I started lengths … on top of hundreds of “there is as he was sure I would study philosophy. to breathe again! no cause for alarm”. How much science “Because philosophy I know I can do, is done in this place in one night? It’s but astronomy — I am not sure if I am After a one year post-doc, I left Italy magic! But then you walk to the platform able to?!” I answered. for a fellowship at ESA/ESTEC, in the and there is the secret. Netherlands. It was my first experience of The sun has set into the Pacific without a living abroad. I left Italy with a suitcase full I am sure that every single person who green flash yet again, and I hurry to start of pizza, spaghetti, mamma, Valpolicella, has had the chance to see this place the observing night. In some ways it felt “cornetto e cappuccino, grazie”, globular has been impressed. You are there, the as if I had just woken up after almost 20 clusters and blue stragglers. Two years Sun is going down, the sky turns red, years, in the middle of the desert, behind later I left ESTEC with a suitcase contain- and you see these machines, as if from a one of the biggest telescopes, with a ing much less spaghetti, but lots of great Kubrick movie or a book by Philip K. clear answer to my childhood question. experiences, memories of nice people, Dick, opening their big eyes to a beautiful

The Messenger 148 – June 2012 55 Astronomical News

sky. This is the secret. Years ago a group were devoted … and others maybe were that photon coming every ten days, with of astronomers had a dream … a desire not. But the desire became a reality. This the aim of discovering the origin of life … that, maybe, looked much bigger than is being human … fulfilling a desire that and we do not have any idea of how the themselves. Many people gave a piece of is so big that it flies way above the indi- Solar System was born. But you are their life for that … many of them were vidual capabilities of those who realise it. there, the Sun goes down, the stars are enthusiastic … maybe some were not … Let’s be honest: the astronomical com- coming: there’s silence … there is no many of them were nice and funny … munity is a funny one … people looking cause for alarm … it’s time to do science. maybe some were not … many of them at galaxies at redshift 10 000, waiting for

External Fellows at ESO

In addition to the ESO fellowships, a his visit to Meudon during my Gruber number of external fellows are hosted Fellowship there in 2004. ESO seemed to at ESO and a profile of one of these me to be definitely different from other fellows is presented. academic environments. There was an unlimited supply of free cappuccino to give any high street café a run for its Yiannis Tsamis money, an endless list of quality seminars each week, and a formidable array of It is customary for these profiles to begin experts and visitors willing to debate the with personal recollections. In honour latest developments in astronomical of this tradition, I submit that my links to instrumentation and data analysis. The ESO can be traced back to the early fact that the place is situated right next 1980s when, seated on my grandma’s to the beer capital of Europe is of course lap at home in Greece, I was watching an added bonus: because sometimes Carl Sagan on our new colour TV set astronomy is thirsty work, as was dem- cruising through the Cosmos on a make- onstrated in the lively 10 pm discussion shift starship. “E-ELT’s home is only a few sessions at the conference “Mapping microparsecs beyond that yellow dwarf Oxygen in the Universe” in Tenerife this star, some billion ewros into the future”, I May! Yiannis Tsamis clearly heard him pronounce. Well, there is an element of truth in it though, as then At ESO everybody also speaks the lan- When the positive results came out there were no health warnings, conveni- guage that the papers are written in, (thank you FP7!), I had only just moved ently, about the corruptive power of TV which makes it all the easier to blend in to a position at the Instituto de Astrofísica on a child’s tender soul. An “E-ELT” was no matter where you come from. I had de Andalucía (IAA) in Granada on a Gran perhaps E.T. misspelled and the “ewro”, my sights set on Garching since then and Telescopio Canarias (GTC) Consolider well that’s actually “euro” in Maltese applied for an ESO Fellowship, but failed. grant to work with Pepe Vílchez, and then according to Wikipedia. Perhaps the euro But failing doesn’t matter one bit as long parenthood followed soon after. Our (or rather the Greek rendering, ευρw´ ) will as you succeed in the end, and so we young family’s time in Granada was great become a standard unit in economocha- asked Bruno Leibundgut in the spring of and I would have stayed at the IAA, if otics theory come the 22nd century. 2008 whether ESO would consider me the chance to move to ESO on a personal as a candidate for a Marie Curie intra- grant had not arisen. It was a difficult My more tangible links with ESO can be European (IEF) fellowship. ESO was in moment because the IAA is a wonderful traced back to winter 2006 when I came volved in other FP7 projects, but had not place and the Spanish colleagues are to stay as a visitor for two freezing hosted an IEF before. My proposal was truly excellent and had been very wel- months to work with Jeremy Walsh on some twenty pages long (as these things coming. I delayed the start of the IEF as VLT FLAMES data of planetary nebulae. usually are), and was evaluated and much as I could and this gave me time I was at the time a postdoc at University ranked by independent experts along to establish lasting links, and to become College London and I knew Jeremy from with many others throughout Europe. involved in Spanish-led projects such as

56 The Messenger 148 – June 2012 Astronomical News

the MEGARA integral field spectrograph or VIMOS. It all seems so far removed San Francisco and Morelia in Mexico are to be installed on the 10-metre GTC. from the reach of the 4.5-inch telescope next in line), all the while benefiting from I still keep back home and with which I the remarkably stimulating environment. For my research I have been making used to split ε Lyrae or observe the scars The people who work here are lucky and good use of ESO’s VLT to study proto- of Shoemaker-Levy 9 on Jupiter in 1994 I guess they know it; they should cherish planetary discs (the theme of my Marie from downtown Thessaloniki. Munich is it in these testing times. Becoming in Curie fellowship), planetary nebulae really an excellent place to live in and volved with ESO has been a truly positive and blue compact galaxies in the nearby work. Holding my fellowship at ESO has experience. Χι´λια ευχαριστw´/mille grazie Universe. I investigate the chemical given me leave to spend considerable to Alessandro and Silvia for putting up composition of these sources through time away, suiting the needs of our family with their personal astronomer. Thanks their emission lines, observed by integral (thanks to the flexible IEF rules), a gener- and all the best, to all ESO staff too. field spectrographs such as FLAMES ous travel allowance (NASA Ames near

Announcement of the Conference The First Year of ALMA Science

12–15 December 2012, Hotel Cumbres Patagónicas, Puerto Varas, Chile

The Atacama Large Millimeter/submil to objects in our own Galaxy, from the Important deadlines: limeter Array (ALMA) Early Science oper- local to the high redshift Universe. While – Registration opens: 1 June 2012 ations started at the end of September the conference will obviously be focused – Abstract deadline: 27 October 2012 2011. Over one hundred high profile sci- on ALMA observational results, pres – Contributed talk selection: 16 Novem- ence projects have been identified as entations and discussions on related the- ber 2012 high priority for execution. The first excit- oretical implications and predictions ing scientific results from Science Verifi- will be included, as well as relevant com- The conference website is: cation datasets and Cycle 0 observations plementary data from other major facili- http://www.almasc.org/2012 have begun to appear in refereed jour- ties. The conference will also be an ideal nals since the beginning of 2012. By the venue to discuss the scientific priorities More details are also available by email: end of this year, the ALMA users com for the upgrades to the ALMA devel [email protected] munity will be in a position to review the opment plan in the context of the first first science results produced by this new results from Early Science. The conference is co-sponsored by and unique facility. the Joint ALMA Observatory and the To allow more ALMA users to propose ALMA partners (ESO, NAOJ and NRAO), The conference will include all the ALMA contributions based on results from with additional support provided by the science topics covered by Early Science their Cycle 0 projects, we have selected EC-FP7 Radionet3 project. observations, from Solar System bodies a late deadline for abstract contributions of 27 October 2012. ESO/S. Guisard (www.eso.org/~sguisard)

The Messenger 148 – June 2012 57 Astronomical News

ESO

European Organisation for Astronomical Research in the Southern Hemisphere

ESO Fellowship Programme 2012/2013

The European Organisation for Astronomical Research in the Southern The programme is open to applicants who will have achieved their PhD Hemisphere awards several postdoctoral fellowships each year. The in astronomy, physics or a related discipline before 1 November 2013. goal of these fellowships is to offer outstanding young scientists the Early-career scientists from all astrophysical fields are welcome to apply. opportunity to further develop their independent research programmes Scientific excellence is the prime selection criterion for all fellowships. in the exciting scientific environment of one of the world’s foremost observatories. We offer an attractive remuneration package including a competitive salary and allowances (tax-free), comprehensive social benefits, and we ESO is the foremost intergovernmental astronomy organisation in provide financial support for relocating families. Europe. Its approximately 110 staff astronomers, 40 Fellows and 50 PhD students conduct frontline research in fields ranging from exoplanets If you are interested in enhancing your early career through an ESO to cosmology, offering one of the most vibrant and stimulating scientific Fellowship, then please apply by completing the web application settings anywhere in the world. form available at http://jobs.eso.org. Reference letters to support your application should be sent to [email protected] for Garching and Fellowships are available both at ESO’s Headquarters in Garching near [email protected] for Chile. Munich, Germany, and at ESO’s astronomy centre in Santiago, Chile. The ESO Headquarters is situated in one of the most active research Please include the following documents in your application: centres in Europe, boasting one of the highest concentrations of astron- – a Curriculum Vitae with a list of publications (ONLY published papers, omers. ESO’s offices are adjacent to the Max Planck Institutes for NOT papers in preparation); Astrophysics and for Extraterrestrial Physics and only a few kilometres – a proposed research plan (maximum two pages); away from the Observatory of Munich’s Ludwig-Maximilian University. – a brief outline of your technical/observational experience (maximum Additionally, ESO participates in the recently formed ‘Universe’ Excel- one page); lence Cluster at the Garching Campus, which brings together nearly – three letters of reference from persons familiar with your scientific 200 scientists to explore the origin and structure of the Universe. Conse- work. quently, ESO Fellows in Garching have many opportunities to interact and collaborate with astronomers at neighbouring institutes. The closing date for applications is 15 October 2012, and review of the application documents — including the recommendation letters — In Chile, Fellows have the opportunity to collaborate with the rapidly will begin immediately. Incomplete applications will not be considered. growing Chilean astronomical community as well as with astronomers at other international observatories located in Chile. The advent of the Candidates will be notified of the results of the selection process new ALMA building next to ESO’s Santiago offices and the arrival of between December 2012 and February 2013. Fellowships shall begin in many astronomers and fellows working on the ALMA project have fur- the year in which they are awarded. ther enhanced the stimulating scientific environment available to ESO Chile Fellows. For more information about the fellowship programme and ESO’s astronomical research activities, please see: http://www.eso.org/sci/ The fellowships in Garching start with an initial contract of one year fol- activities/FeSt-overview/ESOfellowship.html. For a list of current ESO lowed by a two-year extension (3 years total). In addition to developing staff and fellows, and their research interests please see: http://www. their independent research programmes, ESO Garching Fellows will eso.org/sci/activities/personnel.html. Details of the Terms of Service for be expected to engage in some functional work, for up to 25% of their fellows including details of remuneration are available at: http://www. time, related to e.g. instrumentation, VLTI, ALMA, E-ELT, science opera- eso.org/public/employment/fellows.html. tions support either in Garching or at one of ESO’s observatories in Chile, or public outreach. This provides the Fellows with the opportunity For further general information about fellowship applications, please see to get involved with ESO projects or operations, and to gather valuable our Frequently Asked Questions (FAQ): http://www.eso.org/sci/activities/ insights and experience not available in any other setting. FeSt-overview/ESOfellowship-faq.html. Questions not answered by the above FAQ page can be sent to: Eric Emsellem, Tel. +49 89 320 06-914, The fellowships in Chile are granted for one year initially, with annual e-mail: [email protected] (for Garching) and Michael West, extensions for three additional years (4 years total). During the first three Tel. +56 2 463 3254, email: [email protected] (for Chile). years, the Fellows are assigned to one of the science operations groups of Paranal, ALMA or APEX, where they will contribute to the operations Although recruitment preference will be given to nationals of ESO Mem- at a level of 80 nights per year. ber States (members are: Austria, Belgium, Brazil, the Czech Republic, Denmark, Finland, France, Germany, Italy, the Netherlands, Portugal, During the fourth year there is no functional work and several options Spain, Sweden, Switzerland and United Kingdom) no nationality is in are provided. The Fellow may be hosted by a Chilean institution where principle excluded. she/he will be eligible to apply for time on all telescopes in Chile via the Chilean observing time competition. Alternatively, the Fellow may The post is equally open to suitably qualified female and male applicants. choose to spend the fourth year either at ESO’s astronomy centre in Santiago, or at the ESO Headquarters in Garching, or at any institute of astronomy/astrophysics in an ESO member state.

58 The Messenger 148 – June 2012 Astronomical News

The ALMA Newsletter

The ALMA Newsletter provides updates on recent developments at the Joint ALMA Observatory, progress at the ALMA site, in-depth articles on instruments and observing techniques together with calibration, profiles of ALMA staff, reports on workshops and special events, a list of future meetings related to ALMA across the globe, and lots more.

The ALMA Newsletter is available for download at http://www.almaobservatory. org/en/outreach/newsletter. It currently appears twice to three times per year and is edited by Lewis Ball (ALMA Deputy Director), Rainer Mauersberger (ALMA Commissioning Scientist) and William Garnier (ALMA Education and Public Out- reach Officer).

An email alert of new editions can be obtained by email to: almanewsletter@ alma.cl with “subscribe ALMA newsletter” in the body.

More information on ALMA can be found on the ALMA homepage: www.almaobservatory.org

Personnel Movements

Arrivals (1 April–30 June 2012) Departures (1 April–30 June 2012)

Europe Europe Andre, Mathias (A) Web and Advanced Projects Coordinator Banse, Klaus (D) System Analyst Programmer Grudzien, Thomas (F) Software Engineer Lablanche, Pierre-Yves (F) Student Rakich, Andrew (AUS) Optical Engineer Longinotti, Antonio (I) Senior Software Engineer Moresmau, Jean-Michel (F) Electronics Engineer Panić, Olja (BIH) Fellow

Chile Chile Daire, Amal (RCH) Administrative Assistant Argandoña, Gonzalo (RCH) Public Relations Officer Mužić, Koraljka (HR) Fellow Cortes, Angela (RCH) Telescope Instruments Operator Pauwels, Evert (NL) Product and Quality Assurance Yegorova, Iryna (UA) Fellow Programme Manager

The Messenger 148 – June 2012 59 ESO, the European Southern Observa- Contents tory, is the foremost intergovernmental astronomy organisation in Europe. It Telescopes and Instrumentation is supported by 15 countries: Austria, A. McPherson et al. – Recent Progress Towards the Belgium, Brazil, the Czech Republic, European Extremely Large Telescope (E-ELT) 2 Denmark, France, Finland, Germany, F. Kerber et al. – Monitoring Atmospheric Water Vapour over Paranal Italy, the Netherlands, Portugal, Spain, to Optimise VISIR Science Operations 9 Sweden, Switzerland and the United P. Bristow et al. – PILMOS: Pre-Image-Less Multi-Object Spectroscopy Kingdom. ESO’s programme is focused for VIMOS 13 on the design, construction and opera- C. Lagerholm et al. – A Method to Deal with the Fringe-like Pattern tion of powerful ground-based observ- in VIMOS-IFU Data 17 ing facilities. ESO operates three observatories in Chile: at La Silla, at Paranal, Astronomical Science site of the Very Large Telescope, and S. Hubrig et al. – The Chemistry and Magnetism of Young and at Llano de Chajnantor. ESO is the Old Intermediate-mass Stars Observed with CRIRES 21 European partner in the Atacama Large H. M. J. Boffin et al. – POPIPlaN: A Deep Morphological Catalogue of Millimeter/submillimeter Array (ALMA) Newly Discovered Southern Planetary Nebulae 25 under construction at Chajnantor. R. Campbell et al. – 3D Visualisation of Integral Field Spectrometer Data 28 Currently ESO is engaged in the design J. Walsh, L. Testi – First published ALMA Early Science Cycle 0 Result — of the European Extremely Large Mapping of the Fomalhaut Debris Disc 32 Telescope. H. Sana et al. – X-shooter Spectroscopy of Massive Stars in the Local Group and Beyond 33 The Messenger is published, in hard- copy and electronic form, four times a Astronomical News year: in March, June, September and U. Weilenmann – Renewable Energy for the Paranal Observatory 39 December. ESO produces and distrib- T. Rivinius et al. – Report on the ESO/IAG/USP Workshop “Circumstellar utes a wide variety of media connected Dynamics at High Resolution” 42 to its activities. For further information, C. Dumas et al. – Report on the Workshop “Observing Planetary Systems II” 44 including postal subscription to The B. Dąbrowski, M. Karlický – The ALMA Regional Centre in the Messenger, contact the ESO education Czech Republic and the ALMA Winter School in Prague 47 and Public Outreach Department at the The ESO-Chile Outreach Volunteer Team – Volunteer Outreach Activities at following address: ESO Chile 48 J. Meléndez – Inspiring Young Brazilian Astronomers at the ESO Headquarters La Silla Observatory 50 Karl-Schwarzschild-Straße 2 P. Ballester, M. Péron – Retirement of Klaus Banse 52 85748 Garching bei München Staff at ESO – A. McPherson 53 Germany Fellows at ESO – M. Vučković, G. Beccari 53 Phone +498932006-0 External Fellows at ESO – Y. Tsamis 56 [email protected] Announcement of the Conference “The First Year of ALMA Science” 57 ESO Fellowship Programme 2012/2013 58 The Messenger: The ALMA Newsletter 59 Editor: Jeremy R. Walsh; Personnel Movements 59 Design, Layout, Production: Jutta Boxheimer; Layout, Typesetting: Mafalda Martins; Graphics: Roberto Duque www.eso.org/messenger/

Printed by G. Peschke Druckerei GmbH, Schatzbogen 35, 81805 München, Front cover: An 870 μm image from the Atacama Pathfinder Experiment (APEX) Germany telescope taken with the LArge BOlometer CAmera (LABOCA) superimposed on a visible light image (from the Digitized Sky Survey 2) of the M78 region (Orion B Unless otherwise indicated, all images molecular cloud). The APEX image in orange highlights emission from cold dust at in The Messenger are courtesy of ESO, around 20 K heated by dense cores of forming stars. M78 (NGC 2068) is the visible except authored contributions which reflection nebula at the centre of the image but it has a more heavily embedded are courtesy of the respective authors. star formation region to the south with a chain of dense cores (orientation is north up, east left). At the top of the image is another dusty low to intermediate mass © ESO 2012 star formation region, NGC 2071. See Release eso1219 for more details. Credit: ISSN 0722-6691 ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Igor Chekalin/Digitized Sky Survey 2