Astronomy in the Netherlands Strategy for 2001 – 2010

NCA, NOVA, NWO

October 2001 Astronomy in the Netherlands

Strategy for 2001 – 2010

Nederlands Comité Astronomie (NCA) Nederlandse Onderzoekschool Voor Astronomie (NOVA) Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO) – Gebied Exacte Wetenschappen

October 2001

Table of contents

Executive summary

Part I. Present situation and its time derivative: in which direction are we heading?

1. Research infrastructure 1.1. Structure and organizations 1.2. Existing observing facilities 1.3. Human resources 1.4. Financial resources

2. Present research 2.1. Formation and evolution of galaxies: from high redshift to the present 2.2. Birth and death of stars: the life-cycle of gas and dust 2.3. Final stages of stellar evolution: physics of neutron stars and black holes

Part II. Extrapolation to the future

3. Strategic considerations 3.1. International focus, and its national derivative 3.2. Strategic technical research and development 3.3. Coordinated approach in major new investments 3.4. Coordinated approach in human resources

4. Concluding remarks

Appendix

List of abbreviations

ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010 Executive summary

Astronomy – Formation and evolution of galaxies: ical processes under study. For this The ultimate goal of astronomical from high redshift to the present reason it is critical to make observa- research is to understand the Universe – Birth and death of stars: the life-cycle tions covering the full electromagnetic and the objects within it in terms of the of gas and dust spectrum – from gamma- and X-rays laws of physics. The structure of the – Final stages of stellar evolution: to long radio waves – with the greatest Universe and its development over the physics of neutron stars and black sensitivity, the sharpest details in course of time, the nature, formation, holes images and in spectral features. This and evolution of planets, stars, galax- multi-spectral approach also makes it ies, clusters and superclusters of Each area addresses deep physical possible to probe physical conditions galaxies, and the properties of the questions as highlighted in part I. at various depths into objects. medium in which these are embed- Together they constitute the overall ded, are all important objects for theme of the NOVA research strategy: Astronomers in the Netherlands have study. Cosmological questions con- The Life Cycle of Stars and Galaxies. access to the international observing cerning the nature and evolution of the facilities made available through ESO Universe are profound. They relate The ambition to maintain a top ranking and ESA (in particular the Very Large directly to such questions as the geom- in the quality of astronomical research Telescope and the space observatories etry of space-time, the nature of the carried out in the Netherlands requires Hubble, Chandra and XMM-Newton), dark matter which constitutes over (1) access to state-of-the-art observing to the UK/NL optical telescopes of the 90% of the gravitating mass in the Uni- facilities on the ground and in space ING at La Palma, the UK/CND/NL sub- verse but leaves no trace in the form of that cover the entire electromagnetic millimeter JCMT on Mauna Kea, and to electromagnetic radiation, the forma- spectrum, and (2) the ability to attract the fully Dutch-owned WSRT and the tion of the elements and, ultimately, and keep the most brilliant resear- multilateral EVN-JIVE facility. Togeth- the origin of the Earth and of life. Fur- chers, by supporting them with suffi- er, these facilities deliver an outstand- thermore, the Universe provides a cient human resources and computing ing scientific program as judged by unique laboratory for investigating facilities. international review committees. Par- and testing the laws of chemistry and ticipation in these facilities will be sup- physics under conditions far more Computational astrophysics ported as long as they continue to extreme than can be reached in labo- The ongoing increase in computing deliver the highest quality science. ratories on Earth. Astrophysicists power allows the computation of study phenomena involving enor- astrophysical problems of increasing Several revolutionary new observato- mous scales of length and mass (the complexity. The physics required to ries will become available in the next Universe as a whole), huge densities tackle these problems usually involves decade. On the ground, new tech- (e.g., neutron stars, black holes), the combination of different fields of niques are being developed that will extreme vacua (interstellar and inter- expertise, and a variety of computa- routinely correct for the blurring galactic media), immense energies tional methods. Mastering these meth- motions of the atmosphere so that (explosive phenomena such as super- ods, and writing the computer pro- objects can be imaged at ever increas- novae and quasars), and intense fluxes grams to apply them, requires a ing resolution from the ground. This of particles and radiation (neutrinos, long-term investment, both in the also opens the way to the construction gamma-ray bursts). computers themselves and in man- of optical telescopes with diameters power needed to manage these pro- between 30 and 100m. At longer wave- Research focus grams. A number of collaborations in lengths, a global collaboration be- Throughout much of the 20th century, this field are already in place, which tween Europe (ESO), the USA and the Netherlands has held a strong often transcend the boundaries of Japan aims to construct the very large international position in astronomy astrophysics, involving scientists from millimeter interferometer ALMA. New and astrophysics, particularly in the related disciplines in physics and facilities at much longer wavelengths fields of radio astronomy, the interstel- applied mathematics. The various ap- (cm to meters) such as LOFAR and SKA lar medium, structure and dynamics of plications often require different pie- are being planned. In space, NASA, the Milky Way and other galaxies, stel- ces of highly specialized theory, and ESA and their Japanese and Russian lar and solar physics, and, more re- they profit mutually from an intense partners expect to launch a new gener- cently, plasma and high-energy astro- exchange of views and knowledge ation of space observatories. These physics. In order to maintain and between them. include SIRTF, Herschel Space Obser- strengthen this pre-eminent position vatory (formerly FIRST), NGST, and during the coming decade, the astro- Observatories and instruments GAIA. Finally, astronomical databases nomical community in the Nether- Astronomy differs from most other sci- all over the world are being connected lands has decided to concentrate on ences, in that it cannot make in situ so that they can be exploited in con- the following three research areas: measurements of the objects and phys- junction as a world-wide `virtual

EXECUTIVE SUMMARY 5 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

observatory’, available to anyone who grams at the universities carried out by postdoctoral positions as well as state- can access the internet. NOVA on the one hand, and the major of-the-art computational infrastruc- instrumental development and R&D ture. This general research support Technical Research and initiatives at the NWO institutes has been under pressure for the past Development ASTRON and SRON on the other hand, two decades, and significant invest- In the past decades, the Netherlands are fully complementary, well-coordi- ments in human resources and infra- had a significant role in planning of nated, and have sufficient critical structure are required to reverse this new international facilities because the mass. For this reason, astronomers in trend. NWO institutes ASTRON and SRON the Netherlands have chosen to make a offered key technologies and expertise few major investments in well-selected A first step in this direction was taken to strengthen the science potential and new initiatives rather than taking part in the ten-year NOVA program which exploitation of these new observato- in many projects in a ratio of gross started in 1999. It provides funding for ries. In-depth investments in four national product of the partners. overlap appointments for future areas of technical R&D are required to vacancies on the permanent university allow continuation of this active partic- Top priorities for new observing facili- staff, dedicated support staff for reduc- ipation also in the next generation of ties for the coming decade are tion and handling of large data observatories. streams, and graduate students and At SRON, the astronomy related tech- 1. Participation in ALMA through postdocs. Funding of this program nical research is focused on the next ESO beyond the first phase which ends in generation of detectors for X-rays, and 2. ESO VLT-VLTI instrumentation mid 2005 is critical. on possibilities for infrared interfer- 3. NGST mid-infrared camera/spec- ometry from space. ASTRON main- trograph tains its cutting edge expertise in long 4. LOFAR/SKA preparation wavelength radio astronomy correla- 5. JIVE real time VLBI tor design and phased-array technolo- gy, and has added a program in opti- The intent is to terminate participation cal/infrared instrumentation and R&D, in the JCMT when ALMA comes into which includes participation in first operation, and to substantially reduce generation ESO VLT and VLTI instru- support for the WSRT when the next mentation projects. generation radio facility starts opera- tions. Access to groundbased optical The time-scales for the development of telescopes in the northern hemisphere major next generation observing facil- remains a priority especially for fol- ities are long, typically 15-20 yr. The low-up work of new discoveries from four-pronged national R&D effort is in space observatories. For the ING the harmony with the strategy where each resources should be concentrated on NWO institute has two major thematic the 4m WHT to continue to equip this lines, so that at any time, each institute telescope with state-of-the-art instru- has one program in the development mentation. The ultimate goal for La phase and the other in the construction Palma is to establish a European col- phase. Continuation of this successfull laboration to guarantee access to the approach requires an increase of the next generation groundbased optical structural funding of both SRON and telescopes in the northern hemi- ASTRON in order to be able to com- sphere. pete effectively with other European institutes. In particular, the optical/IR Human resources and program at ASTRON needs strength- research funding ening to allow participation in the ESO A key objective for the coming decade VLT and VLTI second generation is to make sure that Dutch astronomy instrumentation programs, and - on can attract and keep the most brilliant longer time-scales - in the develop- researchers. To be able to compete in ment of the 100m telescope OWL. the global arena, access to world-class observing facilities and a vigorous A coordinated approach instrumentation program must be It is essential that the research and complemented by sufficient means to instrumentation development pro- support the top scientists with PhD and

6 EXECUTIVE SUMMARY ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010 Part I.Present situation and its time derivative: in which direction are we heading ?

1. Research Infrastructure ical research in the Netherlands, in the out in interuniversity networks, and The Netherlands has a strong interna- fields of space research and ground- which maximize the scientific exploita- tional position in astronomical re- based optical-infrared and millimeter tion of the available ground-based and search, particularly in the fields of astronomy, respectively. Dutch resear- space-based observatories. It also pro- radio astronomy, the interstellar medi- chers do have influence on the choices vides excellent training for future gen- um, structure and dynamics of the ESA and ESO make, but this influence erations of astronomers. Milky Way and other galaxies, stellar is rarely decisive. There is no equiva- and solar physics, and plasma and lent of ESO or ESA in radio astronomy, Discoveries with large international high-energy astrophysics. This promi- but ASTRON and JIVE (the Joint Insti- telescopes are often made by groups nent position is strongly linked to the tute for VLBI in Europe) in Dwingeloo which have built a novel auxiliary quality of the research education, to play a leading part in organizing Euro- instrument, such as a special purpose which traditionally much care is devot- pean radio astronomy. spectrograph or a new detector sys- ed. Many of the astronomy graduates tem. NOVA initiated Dutch involve- gain postdoctoral and staff positions at 1.1.1. NOVA and universities ment in several instrumentation pro- premier institutions abroad, or obtain Most of the astronomical research in grams for the ESO Very Large Te- good research positions outside of the Netherlands is carried out at the lescope (VLT), the VLT Interferometer astronomy. astronomical institutes of the universi- (VLTI) and ALMA, as well as in an ties of Amsterdam, Groningen, Leiden upgrade of the PUMA pulsar facility on 1.1. Structure and and Utrecht. In 1992, these institutes the WSRT and support of Laboratory organizations decided to collaborate in the Nether- Astrophysics. This strategic effort is At a national level, three organizations lands Research School for Astronomy carried out in cooperation with the have their own area of responsibility: (Nederlandse Onderzoekschool Voor instrumentation groups at ASTRON the research school NOVA, in which Astronomie, NOVA). and SRON, capitalizes on the Dutch the four university astronomical insti- investments in ESO, and provides an tutes of Amsterdam, Groningen, Lei- NOVA’s mission is to carry out frontline excellent complement to the planned den and Utrecht (and in the future also astronomical research in the Nether- ESA Herschel Space Observatory, the Nijmegen) collaborate, and the NWO lands, and to train young astronomers planned NASA-ESA Next Generation institutes ASTRON and SRON, respec- at the highest international level. Grad- Space Telescope, and the initiative for tively. uate astronomy education in the the Square Kilometer Array. NOVA Netherlands is concentrated in NOVA. astronomers are also involved in the The Netherlands Organization for Sci- construction of the Advanced Camera entific Research (NWO) is a semi-gov- In 1998, the Dutch government initiat- for the Hubble Space Telescope. A key ernmental organization that functions ed a research program, the so-called part of the NOVA instrumental effort as a national research council. It was `In-Depth Strategy’ to identify and is the development of a university set up by an act of parliament as an stimulate national focus areas of curriculum for technical astronomy, independent organization, and relies world-class scientific research. Six which includes hands-on experience for its funding almost entirely on the national research schools were select- with instrumentation, special-purpose Ministry of Education, Culture and Sci- ed by the NWO, from 34 applications computing, and data analysis. ence. The NWO institutes receive their covering all academic disciplines. baseline funding from the NWO Gen- NOVA was ranked highest among 1.1.2. ASTRON eral Board. Science policy within these, and received a grant of 21 mil- ASTRON, the Netherlands Foundation NWO is determined through its disci- lion Euro for the period 1999-2005 to for Research in Astronomy, is the tech- pline oriented research councils. As- carry out an innovative program on the nical arm of Dutch ground-based as- tronomy resides under the Council of overall scientific theme: The Life-Cycle tronomy. Its mission is to provide Physical Sciences (GBE, physics, ma- of Stars and Galaxies. This program front-line research facilities in support thematics, computer sciences and as- focuses on the formation and evolution of the community’s research pro- tronomy). The GBE also acts as granti- of galaxies, on the formation of stars grams, with particular emphasis on ng organization for NWO supported and planetary systems, and on the long-term research infrastructure. astronomical research in the Nether- high-energy phenomena which occur ASTRON strives to ensure that the lands. in the stellar populations and in galac- community has access to forefront tic nuclei. It combines three key areas ground-based observing facilities Intergovernmental organizations like of astrophysical research where Dutch across the electromagnetic spectrum. the European Space Agency (ESA) and astronomy has a strong international The present program consists of two the European Southern Observatory reputation. The program has technical, main activities: (1) operation and con- (ESO) determine, in broad outline, the observational, interpretative and theo- tinued enhancement of the Wester- long-term opportunities for astronom- retical components, which are carried bork Synthesis Radio Observatory

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 7 The Very Large Telescope on Cerro Paranal, Chile.The four 8.2 meter telescopes can be used separately,or as an interferometer with superior resolution. In that case the light from their mirrors is guided through tunnels to a common focus in the central buildin (courtesy ESO).

(WSRT) which is again one of the cal design of LOFAR (Low Frequency astronomy (high-energy), and (2) world’s most sensitive instruments of ARray) and of the international organ- infrared and sub-millimeter astrono- its kind after the completion of its ization of the Square Kilometer Array my (low-energy). These two areas are major upgrade program; and (2) devel- (SKA) project. prominent in ESA’s long-range plan opment of innovative instrumentation Horizon 2000 plus. in the radio and the optical-infrared 1.1.3. SRON - astronomy wavelength regions at its technical lab- activities The program for the coming decade oratory in Dwingeloo. In addition, SRON, the Space Research Organiza- includes diagnostics of high-energy ASTRON plays a central role in deter- tion of the Netherlands, is an expertise transients such as X- and gamma-ray mining the future of radio astronomy center of international repute for the bursts (BeppoSAX), X-ray spectro- internationally by hosting the Joint development and scientific exploita- scopy of nearly all known classes of Institute for VLBI in Europe (JIVE), by tion of instrumentation for space cosmic X-ray sources (Chandra and participating through ESO in the observatories for astrophysics and XMM-Newton, operations planned design and development program of earth observations. For astronomy, the until 2010), gamma-ray spectroscopy ALMA, by taking the lead in the techni- main focus is on (1) X- and gamma-ray (Compton GRO, Integral), high-reso-

8 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

lution spectroscopy of the cool uni- pate in future initiatives for space- IRAM, Keck, KPNO and VLA (see list of verse in the mid-IR wavebands (ISO), based interferometry (IRSI/Darwin). acronyms for further information). and ultra-high resolution spectro- scopy of very cold matter (Herschel 1.2. Existing observing In astronomy it is common practice Space Observatory, HSO, 2007-2012). facilities to offer colleagues worldwide access In nearly all these missions SRON has This section describes existing observ- to each others’ observing facilities Principal Investigator (PI) status for its ing facilities with a major Dutch finan- through open telescope time alloca- contribution to the scientific payload. cial contribution. Dutch astronomers tion procedures based on a proposal SRON is actively involved in European also frequently use the Hubble Space judged on scientific merit only. Use of preparatory instrument studies for a Telescope, the X-ray observatories each others’ facilities is in principle possible future 10 meter X-ray tele- RXTE, XMM-Newton and Chandra, free of charge. The overall quality of scope, XEUS, which will require in- the gamma-ray satellite BeppoSax, astronomical research has greatly orbit build-up with the aid of the Inter- and many of the world’s groundbased benefited from this open-minded ap- national Space Station. SRON has also telescopes, including AAT, ATNF, proach. begun to make investments to partici- BIMA, CFHT, CSO, CTIO, GMRT,

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 9 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

1.2.1. European Southern provided by the 8m telescopes, and lar resolution at a spectral resolution of Observatory (ESO) improve the imaging efficiency of the 200-300. MIDI is a collaboration of ESO is an intergovernmental organi- VLTI. By themselves they form an MPIA (Max Planck Institut für zation set up in 1962 to establish and interferometric array which can be Astronomie at Heidelberg, Germany), operate an astronomical observatory used independently. NOVA (universities of Amsterdam and in the Southern Hemisphere and to Leiden), ASTRON, ESO, and other promote and organize co-ordination in In collaboration with other partners, partners in France and Germany. astronomical research in Europe. The the Netherlands makes substantial Delivery to Paranal is also planned for Netherlands is one of the nine (soon contributions to the following VLT or Spring 2002. ten) members of ESO. Its annual con- VLTI instrumentation programs: tribution is 5.5 million Euro per year. In OmegaCam is the wide-field camera return, Dutch astronomers receive VISIR will provide high quality imag- for the VLT Survey Telescope (VST), a about 6.5% of the observing time on ing and spectroscopy with resolutions 2.6m telescope being built for ESO’s the ESO telescopes on La Silla and on up to 10,000 in the 10-20 micron atmos- Paranal Observatory, dedicated exclu- the VLT at Paranal, in Chile, and are pheric windows. Its capabilities are sively to optical imaging. The camera regular users of the Swedish-ESO complementary to SIRTF, and it will cover a field of one square degree Submm Telescope on La Silla. bridges the gap in time between ISO with very fine resolution (0.2 arcsec and HSO. The VISIR project is a uni- pixels). Its focal plane is tiled with a The VLT consists of an array of four 8m versity initiative organized through total of 32 CCD’s, each having 2048 x diameter optical telescopes equipped ASTRON in collaboration with the 4096 pixels. The instrument is desig- with eleven different instruments. The French Center for Atomic Research ned and built by a consortium of insti- four telescopes can be used individual- (CEA), Astrophysics Division at tutions in three countries, which in ly, or can be combined in a incoherent Saclay. Delivery to Paranal is planned turn coordinate the contributions of mode to provide the light gathering for Spring 2002. other institutes: for the Netherlands, capacity of a 16m equivalent diameter NOVA (PI, university of Groningen), telescope, or combined in a coherent MIDI is a prototype fringe detector and for Germany and Italy, respective- mode to provide the angular resolution system that will operate in the 10 ly the observatories of München (co- of a telescope with a larger than 100m micron window at the VLTI. This proj- PI) and of Padova (co-PI). ESO designs diameter. The latter mode is called the ect is a largely experimental effort to and builds the dewar containing the VLT Interferometer (VLTI). The VLTI develop the techniques of multi-tele- CCD detector array. NOVA designs includes a number of smaller movable scope synthesis imaging at near- and and provides the semi-automatic pipe- Auxiliary Telescopes. These enhance mid infrared wavelengths. MIDI will line software to reduce and analyze the the number of baselines over those provide up to 20 milli-arcsecond angu- large data volumes (20 Terabyte/year)

(left) MERLIN + VLA radio image of the central part of the nearby galaxy M82 showing some of the supernova remnants present. Inset are images of the youngest remnant observed in 1986 and 1997 by the EVN. The remnant shows clear expansion over the 11 years. (right) A highly detailed image, observed in November 1988, of the same remnant obtained from a 20-telescope global VLBI array showing for the first time the complex interaction of the ejected material with its surroundings (courtesy JIVE).

10 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

The Isaac Newton Group of Telescopes on La Palma, jointly operated by PPARC and NWO. First on the left is the 4.2 meter William Herschel Telescope, second the Dutch Open Telescope (courtesy ING). this instrument will produce. Delivery imagery. This project is a collaboration agility. These frontends, an enhanced to Paranal is planned in late 2003. of the Max-Planck-Institut für correlator, a broad-band (6 x 20 MHz) Extraterrestrische Physik (Garching, IF system, and a newly designed ‘tied- SINFONI is an instrument that com- Germany), NOVA (University of Lei- array adding unit’ have transformed bines the advantages of integral field den and technical development at the WSRT into a state-of-the-art instru- spectroscopy in the near-infrared with ASTRON) and ESO. Delivery to ment. As a 94-m equivalent single-dish adaptive optics. Both integral field Paranal is planned in 2004. instrument, the WSRT is one of the spectroscopy and adaptive optics are most sensitive radio telescopes in the major growth areas; the combination 1.2.2. Westerbork Synthesis world for continuum and spectral line of these two techniques is even more Radio Telescope (WSRT) studies. The WSRT also serves as one powerful. In the background-limited The WSRT is currently the only major of the backbones of the European VLBI near-infrared regime, adaptive optics observational facility in astronomy Network. gives a strong sensitivity increase for located in the Netherlands. During the small sources. SINFONI will outper- 1990’s a thorough upgrade of the 30- The Pulsar Machine (PuMa) has be- form HST by providing higher resolu- year old telescope was carried out. come a workhorse for pulsar studies at tion in the near- infrared, reaching New low-temperature multi-frequen- WSRT. This state-of-the-art backend, fainter magnitudes in K-band, and cy front-end systems provide a greatly built and designed at the Universities delivering fully spectrally multiplexed enhanced frequency coverage and of Utrecht and Amsterdam, and fur-

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A giant group of sunspots, observed with the Dutch Open Telescope on 2 April 2001. Later on this day,the group caused the eruption of the biggest solar flare in 25 years.The picture has a resolution of 0 ”. 2 (150 km) and is a mosaic of 10 images at a wavelength of 430.5 nm (courtesy DOT). ther upgraded with NOVA-funding, is tions made by this network of radio tel- logical development of VLBI in uniquely equipped to use the capabili- escopes generates images of cosmic Europe. Main elements of the program ties of the WSRT systems for pulsar radio sources with a detail which are: (1) to process EVN observations searches and timing studies. It has pio- would otherwise only be achievable by using the MkIV data processor, which neered interactive remote operations a hypothetical single telescope of can handle data from 16 radio tele- of the facility and observing is regular- (inter)continental dimensions. In the scopes simultaneously and is the most ly carried out from a university. radio wavelength domain the electri- advanced of its type in the world, (2) cal fields of the cosmic radiation can be develop the processor’s capabilities for With proper maintenance of the oper- measured directly, as opposed to other continuum, spectral line and pulsar ational and observing systems, the wavelengths where only the energies research, (3) support the operations of WSRT can continue its productive sci- are measured. This allows for the sig- the EVN and its individual users, entific lifetime for another 10 years. nals of individual telescopes to be including rapid analysis of data quality stored on magnetic tapes in order to be at the EVN telescopes, and (4) initiate 1.2.3. European VLBI Network interferometrically combined at a later front-line astronomical research using and Joint Institute for date at a central facility. The impor- the technical facilities. JIVE also coor- VLBI in Europe (JIVE) tance of this Very Long Baseline Inter- dinates the EVN’s role in space VLBI The European VLBI Network (EVN) is ferometry (VLBI) to astronomy and observations with HALCA. a consortium of 14 institutes who, astrophysics lies in the extremely high between them, control 16 radio tele- angular resolving power achieved 1.2.4. Isaac Newton Group scopes in Finland, France, Germany, which is unequalled by measurements (ING) on La Palma Italy, the Netherlands, Spain, Sweden, in any other part of the electromagnet- The Dutch participation in ING is the UK, Poland, Ukraine and China. ic spectrum. organized through a bilateral partner- Together, these individual centers ship between the United Kingdom and form a distributed large-scale facility, a JIVE is the central institute of EVN, and the Netherlands national research continent-wide radio telescope. The is located in Dwingeloo. Its mission is councils with a 20% NL share. The ING combination of simultaneous observa- to support the scientific and techno- comprises three optical telescopes, the

12 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

4.2m William Herschel Telescope by Spain. With the construction of the plement the increased sensitivity and (WHT), the 2.5m Isaac Newton Tele- 10 m Gran Telescopio Canarias (GTC, resolution of future large millimeter scope (INT) and the 1m Jacobus completion around 2005), this arsenal interferometers (e.g. ALMA). Howev- Kapteyn Telescope (JKT), located on of national observatories has the er, the Dutch astronomical community the Roque de los Muchachos on La potential of becoming an integrated will shift their interest towards ALMA, Palma. The ING offers astronomers in European Northern Observatory. The and their involvement in JCMT will the Netherlands guaranteed access to Dutch astronomical community aims diminish when ALMA becomes scien- optical telescopes in the northern to help establish a European collabora- tifically productive. hemisphere at an outstanding observ- tion on La Palma to guarantee access to ing site, complementing the ESO tele- the next generation groundbased opti- 1.2.6. Dutch Open Telescope scopes covering the southern skies. cal telescopes in the northern hemi- (DOT) sphere. For the intermediate term, the Solar astrophysics is currently experi- The WHT is one of the two scientifical- ING should focus its efforts and encing a renaissance, in which many of ly most productive ground-based opti- resources on the WHT, and the Dutch the unsolved questions of the past thir- cal/IR telescopes in the world. It has a support for the ING has to be main- ty years are being answered. The well-balanced set of workhorse instru- tained at its present level. Netherlands has historically enjoyed a ments which cover a variety of obser- worldwide reputation in the field. Both vational possibilities for imaging and 1.2.5. James Clerk Maxwell theoretical and observational research spectroscopy at optical and near- Telescope (JCMT) on are continuing at a modest level. infrared wavelengths. It also provides Hawaii an excellent platform for deployment The 15-m diameter James Clerk Max- Observational solar physics in the of fast-track private instruments to well Telescope (JCMT) is the world’s Netherlands presently concentrates tackle specific scientific problems. largest radio telescope capable of on the Dutch Open Telescope (DOT) on Dutch astronomers have particular working at submillimeter wave- La Palma, conceived and developed at interest in integral-field spectroscopy lengths. The large size and high accu- the University of Utrecht. It has suc- (presently SAURON and in the future racy of its dish, and the quality of the cessfully demonstrated the open tele- OASIS) and in the Planetary Nebulae Mauna Kea site, are prime advantages scope concept, now being studied for Spectrograph for studying the kine- of the JCMT. Heterodyne instruments the proposed next-generation national matics and stellar populations in galax- allow study of molecular line emission solar facility in the US, and the feasibil- ies. which provide physical diagnostics ity of consistent long-sequence speck- of interstellar and circumstellar gas. le restoration of solar scenes over a The future role of the WHT will be Continuum instruments allow study of wide field. The DOT is currently being focused on (1) exploitation of adaptive interstellar dust. Polarimeters are used equipped with a five-camera multi- optics, in particular at visible and near- in conjunction with both heterodyne wavelength imaging system that infrared wavelengths, in order to pro- and continuum instruments to deter- combines synchronous speckle recon- vide imaging and spectroscopy at mine magnetic field strengths and struction with tomographic diagnos- increased spatial resolution, and (2) alignments. tics to provide simultaneous long- multi-object spectroscopy over a wide duration image sequences of the field. Both areas provide important sci- The JCMT routinely produces out- magnetic field topology in the deep ence capabilities competitive with, and standing science in a wide range of solar photosphere, the middle chro- complementary to those at larger tele- research areas, and will continue to do mosphere and the high chromos- scopes. In this way the WHT optimally so for several more years to come. phere. The science that becomes feasi- exploits the excellent properties of the SCUBA has revolutionized (sub)mil- ble with this high-resolution field La Palma observatory site and the limeter astronomy over the last few mapping addresses the structure and quality of the telescope and its infra- years, while upcoming array hetero- dynamics of magnetic fields through- structure, whilst offering a long-term dyne line receivers, and the planned out the solar atmosphere, a key area of development path that provides interferometric link between the solar physics. The niche is unique in important instrumentation capability JCMT and the Smithsonian Submil- Europe, complementary to Big Bear to the astronomical community. limeter Array (SMA) will be mid-term Solar Observatory (9 hours away), priority goals to maintain a world- complementary to the adaptive optics The Roque de los Muchachos is the leading position. Further improve- efforts at other leading solar tele- only quality site for astronomical ments of the surface (to enable the tele- scopes (which will concentrate on observations in Europe, and also hosts scope to work better at higher high-resolution spectropolarimetry the DOT (see 1.2.6) and telescopes of frequencies) and even larger array over a single isoplanatic patch), and Belgium, Italy, and the Nordic Coun- instruments may enable the JCMT to complementary to the solar telescopes tries, with common services provided become a survey instrument to com- in space which map the coronal field

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 13 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

Table 1: Astronomers in the Netherlands topology in EUV lines. Continuation of the DOT will keep solar physics in the The number of filled research positions in astronomy and related technical R&D Netherlands at the frontier of solar and construction programs funded by the universities, by NWO or through other research, with a new and invigorating resources, respectively. Positions at JIVE are excluded because of the multi- emphasis on unparalleled high-reso- national nature of that organization. The NWO funded astronomy positions lution observations. include 11.9 fte permanent staff and 9.5 fte postdocs and 7 fte PhD students at ASTRON/SRON, and 6.3 fte postdocs and 17.8 PhD positions at the universities 1.3. Human resources funded through the grant program of NWO/GBE (May 2001). The astronomical community in the Netherlands consists of over 180 Staff / funding resource Univ NWO Other Total researchers, 160 of which work at the university institutes, and another 20 Astronomers are based at the NWO institutes Permanent staff 50.1 12.4 1.0 63.5 ASTRON and SRON. The university Postdocs 10.0 15.8 11.0 36.8 groups together comprise 50 perma- PhD students 45.8 24.8 9.3 79.8 nent scientific staff members, about 30 Subtotal astronomers 105.9 53.0 21.3 180.1 postdocs, and about 80 graduate stu- dents. In addition, ASTRON, SRON Technical research staff 10.7 29.4 0.8 40.9 and the university institutes together have about 40 academic trained Total 116.6 82.4 22.1 221.0 researchers working on technical R&D projects, and on construction of instru- mentation and related software pack- Table 2:Annual astronomy budget in the Netherlands ages. More details are given in Table 1.

Expenditure in astronomical research in the Netherlands for the year 2000 as 1.4. Financial resources shown according funding resources. JIVE is excluded because of the multi- The Netherlands spends 50 MDper year national nature of that organization. The Dutch contributions to JIVE are includ- on astronomical research, or about 3 D ed in the figures of the GBE and ASTRON. per year per citizen. Details are pre- sented in Table 2. About 98% of the Annual budget for year 2000 funding comes from the national gov- ernment, 1% from EU programs, and Universities in Mfl in Mc the remaining part from various University departments 13.0 5.9 resources (private funds, commercial NOVA program (research+instrumentation) 5.2 2.4 companies, and donations from Subtotal universities 18.2 8.3 abroad). The Ministry of Education, Science and Culture provides up to NWO general program 95% of the resources through three dif- ASTRON basic funding 12.1 5.5 ferent budget lines. These are ‘interna- SRON astronomy basic funding 12.5 5.7 tional collaborations’ (22.4 MD per Other 2.1 0.9 year), the national funding agency Subtotal NWO general program 26.7 12.1 NWO (16.8 MD per year), and through the funding of the university groups NWO physical sciences 10.3 4.7 (8.3 MD per year). In addition, the Min- istry of Economic Affairs also con- Government tributes to the Netherlands’ annual ESO 12.0 5.5 subscription to ESA, and on a case by ESA astrophysical program 37.2 16.9 case basis also to some technology Subtotal government 49.2 22.4 developments programs at ASTRON and SRON. Since the allocations of the External funding 5.3 2.4 Ministry of Economic Affairs are justi- fied on economy stimulating merits Total NL astronomy 109.7 49.9 only, these resources are not included in the astronomy budget as shown in Table 2.

14 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

2. Present Research research area are the VLT, medium- ments such as SAURON, OASIS, the sized optical telescopes equipped with Planetary Nebula Spectrograph on the 2.1. Formation and evolution of special purpose instrumentation WHT, and the EVN and WSRT in the galaxies: from high redshift (WHT and VST), the HST, the X-ray radio domain. to the present observatories Chandra and XMM- The study of the high-redshift Uni- Newton, the EVN-JIVE, WSRT, and, in 2.1.3. Mass distributions verse poses some of the most fascinat- the longer term, ALMA and the NGST. Galaxies and clusters of galaxies are ing and fundamental problems in The research currently concentrates dominated by extended dark matter, modern astrophysics. The extremely on three areas. and their mass distributions are there- smooth microwave background re- fore very difficult to measure. Several veals that the Big Bang was remark- 2.1.1. High redshift galaxies techniques are being used: the tradi- ably uniform. Recent technological Radio observations have turned up tional measurement of rotation curves developments have made it possible to objects at high redshifts (e.g. the West- of cold neutral hydrogen gas (21 cm observe galaxies and quasars out to erbork Northern Sky Survey). Efficient line, WSRT), stellar dynamical model- redshifts beyond 6, corresponding to a techniques in mm and optical wave- ing of spectroscopic data, X-ray meas- time when the Universe was less than lengths now exist for identifying the urements of hot gas, microlensing in 5 % of its present age. This shows that most distant galaxies. Much work still nearby objects, and weak lensing by they must have formed in less than a needs to be done to determine the galaxy clusters. It is now possible to billion years. Instead of drawing con- detailed properties of galaxies at red- extend mass determinations for nor- clusions about how galaxies are shift around 1, and comparing the mal galaxies out to substantial red- formed and evolve from a combination properties of these distant galaxies to shifts, which also provides informa- of theoretical modeling and observa- present-day (nearby) galaxies. The tion on cosmological parameters. tions of their present-day structure in goal of such studies is to map in detail the nearby Universe, it is now possible the history of star formation in the uni- 2.2. Birth and death of stars: the to observe distant galaxies directly, verse, and its relation to the assembly life-cycle of gas and dust when they were still young. In this way of whole galaxies. Key instrumentation New stars and planets continue to be we can measure, rather than predict, includes multi-object spectrographs born deep inside molecular clouds in their evolution over most of the age of capable of observing many objects galaxies. What are the physical the Universe. simultaneously, sensitive wide-field processes that lead to these new solar cameras enabling efficient searches systems, and how do they evolve? The formation process appears to have for rare objects, and sensitive VLBI What is the role and origin of magnetic started with the formation of dark mat- observations to help distinguish star- fields, and how do they affect the accre- ter halos. Inside these halos gas then bursts from active nuclei in these dis- tion processes? How is the chemical cooled and star formation took place, tant objects. composition of the gas and dust involv- followed by the chemical enrichment ing the major biogenic elements modi- of the initially pristine gas. When and 2.1.2. Nearby galaxies fied during the collapse from the cold, how did the first structures appear that Study of the structure of nearby galax- tenuous interstellar medium to the evolved into galaxies? When and how ies provides a vital reference point for dense protoplanetary material? Dur- did galaxies first form stars? How is the the higher-redshift work. Integral- ing the late stages of their life, stars mass distributed in galaxies? What field spectroscopy of the integrated have a strong wind. The heaviest stars causes the different galactic mor- stellar light is used to study the kine- explode as a supernova. Both stellar phologies? When and how did galax- matics of stars and gas and the line- winds and supernova transport mate- ies develop active nuclei? What is the strength distributions of the stellar rial enriched with nuclei formed by relation between star formation and populations in nearby galaxies. Similar nuclear fusion within the stars into the nuclear activity, and how did it evolve studies of the resolved stellar popula- interstellar medium. How does this during the history of the Universe? tions are possible for the Milky Way material change the chemical evolu- When and how did the first heavy ele- and its nearest satellites and neigh- tion of a galaxy and of the newly ments, molecules and dust form? bors. The aim is to determine the intrin- formed stars? What drives the mass sic dynamical structure, the history of loss, and how does it influence stellar The strong Dutch expertise in studies metal enrichment, the influence of the evolution? of galaxies on the one hand, and on environment on the star formation his- stellar evolution on the other, provides tory in galaxies, the role of dark matter Research activities in the Netherlands an excellent opportunity for collabora- and a massive central black hole in in this field are aimed at making opti- tive progress in understanding the link shaping galaxies, and the nature of mal use of existing observational facil- between stellar and galactic evolution. activity in nuclei. This research relies ities such as the ISO data base, the VLT The most important facilities for this heavily on special-purpose instru- and the JCMT, as well as new instru-

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 15 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

mentation which comes online in the next few years, including VISIR on the VLT, the JCMT/SMA connection, SOFIA, SIRTF and MIDI on VLTI, and, in the longer term ALMA, HERSCHEL and NGST. Present research uses a unique combination of expertise in dif- ferent disciplines, ranging from obser- vations to astrophysical models, in- depth studies of basic physical and chemical processes, radiative transfer and laboratory astrophysics. The pres- ent research activities are focused on the three following themes:

2.2.1. The earliest stages of star formation Molecular clouds are the primary sites of star formation. Because of (self)gravity, (parts of) clouds can col- Dutch astronomers in an international team used a ‘gravitational lens’ to find this lapse, leading to the formation of pro- extremely distant ‘baby’-galaxy at more than 13 billion light years.The image tostars in the center. During the initial (insert) was magnified and split in two by the gravity of the foreground galaxy stages of star formation, the radiation cluster Abell 2218 (courtesy NASA/HST/Kuijken). from the protostars is extinguished by hundreds to thousands of magnitudes and the full energy escapes at infrared the primitive solar nebula have been uum and lines, will be developed to to mm wavelengths. Existing ISO formed around a large fraction of pre- probe the phase of high mass loss dur- data, especially the spectra taken with main sequence stars, but little is known ing the death struggle of stars. Future the Dutch/German instrument SWS, about their evolution. In particular, high angular resolution instruments at combined with new space infrared their development into the much less infrared, millimeter and centimeter experiments and ground-based sub- massive ‘debris’ dust disks surround- wavelengths will be used to reveal the millimeter data, will be exploited to ing main-sequence stars is poorly onset of dust formation and the study the interaction of the radiation understood. Comprehensive pro- physics of the stellar winds. Systemat- and outflow from the young star with grams using mid-infrared data from ic studies using the unique ISO data- its surroundings, and to probe the VISIR/VLT, SIRTF and/or SOFIA com- base and complementary ground- evolution of the molecular composi- bined with higher angular resolution based observations will provide new tion of the gas. Comparison with labo- JCMT/SMA and VLTI data, will be used insight into the underlying stellar pop- ratory data will provide identifica- to study the properties of the dust and ulation and their distribution. tions of the observed features, as well the gas-to-dust ratio during the plane- as insight into the basic chemical tary formation period of 1-100 Myr. 2.3. Final stages of stellar processes occurring in the laboratory Comparison has already been made evolution: physics of interstellar space. High-angular with the physical and chemical proper- of neutron stars and resolution data such as provided by ties of primitive bodies in our own solar black holes the SMA/JCMT connection will be system such as Kuiper-Belt objects and Neutron stars and black holes – com- used to study the formation and comets. These studies also serve as a pact objects – are of fundamental growth of disks around low- and high- first step into the new discipline of physical importance. Their observable mass stars. New insight into the most astrobiology, in which the building properties depend directly on uncer- massive young stars in the Galaxy will blocks for life and the possibilities for tain aspects of space-time and matter be obtained through groundbased life elsewhere in the universe are and therefore they can be used to learn infrared observations. investigated. about these most basic constituents of the physical world. Neutron star mat- 2.2.2. Evolution of 2.2.3. Late stages of stellar ter is the densest known. By measuring circumstellar disks and evolution the mass, radius or spin of a neutron formation of planets Theoretical models of the physical and star one probes unanswered questions Circumstellar disks, consisting of gas chemical structure of stellar winds, as concerning the nature of matter. The and small dust particles, comparable to well as the radiative transfer in contin- very strong gravity of a black hole

16 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

The Short Wavelength Spectrometer on the ISO-satellite, built by SRON, has provided a unique view of the molecular universe.The planetary nebula shows strong jets emanating from the central star ( not visible).The 13-16 micron spectrum reveals acetylene (C2H2) in the ejected gas; the insert around 14.9 micron provides the first evidence for benzene in space. (courtesy NASA/HST/Tielens).

severely warps nearby space-time, The first detection allowing to look for exotic strong-field of emission by general-relativistic effects such as HD (deuterated unstable orbits, rapid frame dragging molecular and event horizons (black holes). Com- hydrogen) outside pact objects exhibit themselves in vari- the solar system ous ways. The hot relativistic flows in provides impor- X-ray binary systems diagnose how tant data on matter moves in strong-field gravity. deuterium in Gamma-ray bursts are observable space. Deuterium across the Universe, thus providing a was only created unique cosmological probe. Radio pul- during the Big sars are a relativist’s dream: point Bang and is masses equipped with nature’s best destroyed in stars, clocks, probing any motion or space- so its abundance time disturbance with exquisite preci- is a measure of sion. The energetic processes associat- galactic chemical ed with compact objects are the subject evolution of intense theoretical scrutiny – the (courtesy ultra-energetic cosmic ray particles Van Dishoeck) that occasionally strike our atmos- phere must originate there. ing fundamental physical information. identifications of gamma-ray bursts The research program in the Nether- Recent successes include the discov- (using BeppoSAX and optical observa- lands is focused on the astrophysics, ery (with RXTE) of ultrafast oscillations tories), establishing gamma-ray bursts formation, and evolution of neutron in neutron stars, probing deeper than as the most powerful sources of radia- stars, black holes, and their host sys- ever before into these objects’ gravita- tion in the Universe, and the 20-year tems. This research is aimed at extract- tional well, the first optical and X-ray anticipated discovery of the first accret-

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 17 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

ing millisecond pulsar. A host of new observational opportunities has just become available to study these objects across the electromagnetic spectrum, and several more will be added over the next years. All areas highlighted below benefit from the giant optical telescopes now becoming readily available. The rapid improve- ment of numerical capabilities is rapid- ly opening up many previously intractable theoretical problems to direct investigation. The following summarizes the foci of research in the Netherlands in these areas.

2.3.1. X-ray binaries Some of the most energetic gas flows in the Universe occur close to a compact object. Strong gravity pulls gas from an accompanying star. By observing the radiation from the gas close to the compact object, i.e. deep down the potential well, fundamental informa- tion on the compact objects is obtained. X-ray and gamma ray spec- tra and, for stellar mass objects, sub- millisecond time-variability are the best observational diagnostics avail- able. Astronomers in the Netherlands have been very successful in exploiting timing and broad-band spectroscopic diagnostics; enormous new opportu- The Crab nebula, the remains of a supernova explosion seen on earth in nities have been opened up to us July 1054 AD (courtesy ESO/VLT). recently with the launch of the high- throughput high-resolution X-ray spectrographs on Chandra and XMM- 2.3.2. Gamma ray bursts gamma-ray bursts, in principle Newton, missions dimensioned to last The formation of neutron stars and observable out to redshifts z of 20, are a decade. In 2002, the launch of Integral black holes is the outcome of the last potentially a unique probe of the high- will provide similar breakthroughs in stage in the evolution of massive stars. z universe. With the recent launch of gamma rays. Often part of the energy Their birth is believed to be often asso- HETE gamma ray burst astronomy has associated with the accretion process ciated with explosive events such as entered a new era, where prompt is converted into near-light-speed col- supernovae, or possibly hypernovae. localization allows immediate follow limated outflows (jets). Such flows are Hypernova are now believed to be the up observations of radio, optical and seen near some accreting stars in our source of most gamma-ray bursts: the high-energy afterglows. Integral galaxy, leading to the phenomenon of most powerful explosions after the big (2002), SWIFT (2003) and GLAST (2005) ‘micro-quasars’, which may contain bang, where the equivalent of one will provide a continuous increase of information about the physical solar mass is converted into energy. our observational high-energy capa- processes in the much more powerful Other gamma-ray bursts may be bilities. The Netherlands play a leading (and distant) quasars. The new sensi- caused by the merger, and hence role in optical follow-up studies with tive receivers in the world’s biggest destruction, of two compact objects. In ESO’s Very Large Telescope. radio telescopes (VLA, WSRT) have both scenarios the central engine may just opened up this physics for scrutiny be a super massive torus around a 2.3.3. Radio pulsars in not just the brightest, but the major- forming black hole which produces a Evolutionary links between X-ray ity of the X-ray binaries. hyper-relativistic particle jet. Because binaries and radio pulsars help us they are so very luminous and distant, understand the evolution of the mag-

18 PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

(i) (ii)

0 Time (s)100 0 Time (µs)40

The center of the Crab nebula contains a pulsar,which rotates once every 33 milliseconds. It is one of only two known pulsars emitting Giant Pulses, which can be hundreds of thousands of times stronger than normal pulses. Panel (i): 100 seconds of observation of the Crab pulsar.Large spikes are Giant Pulses (normal pulses are too weak to be seen individually) Panel (ii):A single Giant Pulse. It last only 30 microseconds, while normal ones last 5 milliseconds (courtesy PuMa/WSRT). netic field of neutron stars, and thereby Chandra and XMM-Newton, which the physics of their superconducting can map the distribution of chemical interiors. The PuMa pulsar equipment elements in some nearby supernova installed at the WSRT allows very remnants. This provides information detailed observations of the radio puls- about how the supernova explosion es generated in pulsar magnetos- ejects stellar material into the interstel- pheres, with a very high time-resolu- lar gas. Processes powered by the rota- tion in a large number of frequency tional energy of a rapidly spinning pul- bands. Observations of the detailed sar, result in relativistic winds. The large pulse profile at different frequencies resolving power of Chandra allows us yield important clues about the physi- to see the X-ray nebulae resulting from cal processes responsible for the gen- these winds around some nearby pul- eration of the pulsar emission, and its sars. The production of energetic parti- location in the pulsar magnetosphere. cles, both leptons and hadrons, seems a The observation of pulsar arrival times common process near compact objects. allows us to monitor the rotation rate of Jets and supernova remnants produce the pulsar or, for binary pulsars, the relativistic electrons which make them change in pulsar orbits due to emission powerful radio sources by the synchro- of gravitational radiation, while the tron mechanism. Supernova remnants propagation of their radio pulses maps are believed to be the source of galactic out otherwise undetectable compo- cosmic ray nuclei, while the remnants nents of the non-luminous matter in of gamma-ray bursts may produce the our Galaxy. highest energy particles known to man: the ultra-high-energy cosmic rays. A 2.3.4. Particles and shocks number of the competing production A study of the association of pulsars models exist at the highest energies, with supernova remnants yields infor- and observations with near-future mation about the physics of the explo- instrumentation of gamma-rays (Inte- sion in which both the remnant and the gral) and neutrinos (ANTARES) can pulsar were born. Additional informa- potentially distinguish different pro- tion is now becoming available from duction mechanisms.

PART I. PRESENT SITUATION AND ITS TIME DERIVATIVE: IN WICH DIRECTION ARE WE HEADING? 19 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

The barred galaxy NGC 1365 (courtesy VLT/ESO)

20 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010 Part II.Extrapolation to the future

3. Strategic considerations research environment that attracts the IRSI/Darwin are under study for Over the past 50 years the pace of best scientists, are crucial. launch around 2015. The same time astronomical research has been frame may see the launch of LISA, a increasing at a remarkable rate, 3.1. International focus, and gravitational wave experiment devel- caused by rapid technological devel- its national derivative oped jointly between ESA and NASA. opments and by a growing number of New observational facilities are organ- Dutch scientists also participate in astronomers. The public interest in the ized through international collabora- some of ESA’s Solar system missions, Universe and all that it contains has tions in order to remain affordable. including Mars Express, Cassini Huy- increased even faster. The most Within Europe, organizations like ESA gens, and the Rosetta Cornerstone important of the technical develop- and ESO lead the way and take the mission. ments are: (i) the widening of the most important decisions on the future accessible electromagnetic window of astronomy. It is good strategy for the ESO will add the 4m wide-field tele- through the development of tele- Netherlands to be actively involved in scope VISTA to its arsenal in 2005, and scopes and detectors at radio, the choices made supra-nationally. coordinates European participation in infrared, UV, X-ray and gamma-ray This can be achieved by active partici- the construction of the giant millimeter wavelengths, (ii) better sites for all pation in the international science interferometer ALMA, which will be observatories, with space as the ulti- working groups, advisory committees, completed by 2010. ESO has recently mate platform, (iii) continuing and councils that prepare or take these initiated the planning for second gen- improvements in detector technology, decisions. This requires a continuation eration instruments for the VLT and not only in sensitivity, but also in size, of the pro-active role from the Dutch VLTI. While elsewhere in the world, reliability, linearity and dynamic astronomical community, as well as notably in the USA, detailed designs range, and (iv) the availability of ever support from the national funding are being developed for 30m class opti- more powerful computers for agency NWO for long-term strategic cal telescopes, ESO has decided to improved telescope control, data development programs (15-20 years) develop detailed plans for a ground- acquisition and reduction, and for and for financial and organisatorial based 70-100m class optical telescope developing increasingly sophisticated stability of the research institutes. (OWL, OverWhelmingly Large Tele- physical models of what is observed. scope), which would be able to obtain ESA’s science program foresees the spectroscopic measurements on even All this has provided a view of the Uni- launch of a number of astronomical the faintest objects detected by NGST. verse that is deeper and more complex. observatories in the coming decade. The idea of a 100m class telescope orig- Astronomers often simultaneously University researchers participate in inated in 1997, when it was assessed study an object at different wave- the development of these missions. that true progress in science perform- lengths. This problem-oriented multi- The X- and Gamma-ray mission Inte- ance after HST and the 8-10m class spectral approach is essential for gral will be launched in 2002, and the Keck and VLT generations would understanding the objects and physi- far-infrared/submm telescope Her- require an order of magnitude cal processes observed. The discovery schel Space Observatory (HSO, Cor- increase in aperture size. OWL could that gamma-ray bursts are produced nerstone 4, formerly called FIRST) will operate at full resolution and in core collapses of massive stars, pre- be launched in 2007 together with the unequalled collecting power by 2015. sumably leading to black hole forma- cosmic background radiation mission tion, that happened early in the history Planck. Both Integral and HSO have Early on, ESO and ESA provided all the of the Universe is an outstanding Dutch mission scientists, and the HIFI infrastructure required for new and example of this multi-spectral ap- instrument on HSO has a Dutch PI. The outstanding research with their facili- proach. NGST, a 6.5m successor to the HST for ties. In the past two decades, however, the 2-25 micron wavelength region, is both organizations have begun to rely It is impossible to predict which tech- being developed jointly with NASA on the development and construction nological and/or computational devel- and the Canadian Space Agency and of back-end instrumentation opments will lead to the most fruitful will be launched in 2009. The next ESA (receivers, detectors, spectrographs) scientific discoveries. Most likely, as Cornerstone mission for astronomy is by their member countries. There is a has been the case in the past, the most GAIA, which will be launched before financial aspect to this policy, but it also important breakthrough will be 2012, and will provide distances and opens the doors for new concepts and unforeseen. Although unique obser- motions of over a billion stars in the new technology. For example, much of vational facilities and expertise are a Milky Way and beyond with accuracies the success of ISO is due to the SWS prerequisite for many research pro- more than a factor 100 improved over spectrograph built by SRON. The grams, follow-up observations at other Hipparcos. The next generation X-ray Dutch astronomical community wavelengths, interpretative and theo- telescope XEUS, as well as a mission to should be prepared to exploit the retical work, and a stimulating study extrasolar planets called advantages of this policy: an early and

PART II. EXTRAPOLATION TO THE FUTURE 21 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

better awareness of what measure- A technological step towards SKA that MIDI for interferometry at the VLTI, ments will soon be made possible and is being planned by ASTRON, with the latter project in collaboration with what questions can now be answered. MIT and the US Naval Research Labo- NOVA). University astronomers par- We emphasize this national task (and ratory is LOFAR. This array will open ticipate actively in the development opportunity!) to prevent the thought the largely unexplored electromagnet- teams. that the annual contribution to ESO ic window on the Universe at wave- and ESA is the complete entry ticket for lengths of order 10 meters. It is 3.2.1.1. SKA and LOFAR the Dutch scientific community to the planned to start operations in 2006- SKA is a distant, but well identified cor- international observatories. An active 2008. nerstone of ASTRON. As part of an role in the development and construc- international collaboration, ASTRON tion of new instruments has significant 3.2. Strategic technical is focusing on the technical design for rewards: it allows the builders to do the research and development SKA at frequencies below 1.5 GHz; this most successful research. Further- The time needed to develop a funda- includes the 21cm hydrogen line as it more, major contributions to a few mentally new observing technology is becomes redshifted over the history of well-selected instruments strengthen typically 15-20 yr. It is crucial that both the Universe. At radio wavelengths, the Dutch role in the international deci- ASTRON and SRON remain active in unlike in other wavebands, primary sion making process. Funding for two technology areas each, so that at detection of signals may take place in instrument development (including any time each institute has one pro- the aperture plane rather than in the fundamental research on improve- gram in the development phase and focal plane of the telescope. Complete ments in detectors) at NOVA, ASTRON the other in the construction phase. In control of the wave front in the pro- and SRON (in collaboration with for- the early R&D phases ASTRON and cessing electronics of such an array eign partners) must have high priority SRON require strategic collaborations antenna is possible and the telescope because it strengthens the national with technical universities, and inter- can “look” in many directions simulta- participation in international organi- national partnerships. In the construc- neously. SKA can thus simultaneously zations. This funding is complementa- tion phase ASTRON or SRON demand carry out several major research pro- ry to the direct contributions to ESO active participation of university grams and at the same time serve many and ESA. astronomers. In-depth investment in individual users. In addition, exceed- human resources and long-term com- ingly clean measurement beams can Unlike the situation for other wave- mitments of key-individuals are essen- be constructed and unwanted interfer- lengths, radio astronomy does not tial for success. This requires an ing signals can be suppressed. Once enjoy the existence of a large interna- increase of the structural funding of the technology has become mature, tional organization to promote its both institutes. In particular, the opti- SKA will revolutionize radio astrono- future. Among the nations active in cal/IR program at ASTRON needs my. The challenges for SKA R&D are to radio astronomy, the Netherlands has strengthening to allow participation in develop very-wide-band and very- historically played a pioneering and the ESO VLT and VLTI second genera- low-noise phased arrays at low cost leading role. ASTRON’s plan of long tion instrumentation programs, and - per square meter (cheaper than wall- term facilities has been predicated on on longer time-scales - in the develop- to-wall carpet). maintaining this leading role. Current- ment of the 100m telescope OWL. ly the WSRT is as sensitive in its main The required photonics devices and modes as any comparable radio tele- Table 3 summarizes the strategic tech- systems capable of transmitting and scope in the world. The initiative of last nical R&D areas, as well as the level of rapidly switching many tera-bits of decade to host JIVE and take an active required additional funding for the data per second are far beyond what is role in organizing the European VLBI period 2001-2010. commercially available today. The pro- Network have established ASTRON as jected needs of the ICT industry are an important facilitator on the Euro- 3.2.1. At ASTRON very similar, and the development pean science scene. ASTRON’s long-term program builds activities for SKA are expected to be of on existing expertise and facilities in substantial interest for industry. The The next important step in radio astron- radio astronomy and develops new design of optimized detection circuitry omy will be ALMA, and thereafter the instrumentation also in support of uni- that includes the antenna element as Square Kilometer Array. SKA will be an versity research in optical/IR astrono- part of the circuit is a formidable com- essential complement to ALMA, OWL my. Instrumentation is developed for a putational challenge that requires and NGST. European participation in wide range of applications and tele- development of new algorithms and SKA is foreseen to be financed through scopes. Recent major projects con- strategies. ASTRON aims to provide a the EU beginning with the Seventh cerned apparatus for radio telescopes series of demonstrator antennas for Framework Program from 2008 and (WSRT, EVN and JIVE) and for infrared system engineering development and could be completed by 2012. instruments (VISIR for the VLT and for use as testbeds on which the new

22 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

Table 3:Strategic technical R&D for astronomical instrumentation in 2001-2010 adaptive beam control including inter- ference suppression, and integration Planned technical R&D at ASTRON and SRON for future astronomical instru- into the world wide internet. The proj- mentation in MD. Figures are the requirements summed over the period 2001- ect is expected to have strong synergy 2010, unless stated otherwise. with the national and international Data-GRID developments. In addition, Total New funding Remarks LOFAR will serve communities outside the usual astronomical institutes and ASTRON thereby promote inter-disciplinary Phased array antenna SKA 10 2.5 a, b cross-fertilization. Optical/Infrared instrumentation 4 2.5 a, c 3.2.1.2. Optical/IR SRON instrumentation Detector development for X-rays pm pm a, d ASTRON also develops innovative Optical/infrared space interferometry 4 3.5 a, e, f auxiliary instrumentation in the opti- cal-IR wavelength range. The focus on Total 18 8.5 optical-IR complements SRON’s investment in far-IR/sub-mm tech- Remarks nologies. This part of ASTRON’s tech- a. Investments on top of regular institute budget. nical development program is current- b. R&D program for 2001-2005 following successful pilot study in 1997-2000. Requirement is 2 MD per ly financed from a diversity of sources, year of which ASTRON + its industrial partners can provide 1.5 MD per year. NWO-GBE is asked to including the competitive grants pro- provide 0.45 MD per year for at least 2001-2005. The technology demonstrator is incorporated in the grams of NWO, the NOVA instrumen- LOFAR program. tation fund, and the ESO instrumenta- c. R&D program for 2002-2010 focused on optical interferometry and adaptive optics with applications tion program. It is particularly towards OWL. From 2007 onwards this program might be funded through reduction of the Dutch vulnerable to unexpected short term contributions to the ING and/or JCMT. fluctuations in funding, and requires d. Major funding through SRON and ESA’s technology program. Seed funding (0.45 MD) for the period substantial structural institutional 2000-2004 is already available through an NWO-GBE grant approved in 2000. funding. e. Required matching funds for the R&D program to demonstrate imaging opportunities for the IRSI/Darwin mission. Collaboration between SRON, NEVEC and TUD. For centuries, optical images obtained f. ESA may fund participation in SMART2, a technology demonstration mission planned as precursor from the ground have suffered from for IRSI/Darwin in 2006-2007. blurring by “seeing” resulting from atmospheric turbulence. The availabil- ity of fast computers has made it possi- theoretical insights can be tried out in protection of the best possible sites in ble to correct for seeing by means of a practice. Individual investigations are the world. deformable mirror controlled by a being carried out to discover design wavefront sensor. There is now a very approaches and computational strate- The LOFAR project combines innova- rapid development in these Adaptive gies, which if successful will make new tive technologies with strong industri- Optics (AO) capabilities, not only kinds of antenna systems possible. It is al participation to yield two orders of because of astronomical interests, but essential that fundamental R&D will be magnitude improvement in sensitivity also for commercial applications (e.g., continued for at least several more and in a similar improvement in angu- eye surgery). All major astronomical years. Spin-off to the commercial and lar resolution over any existing or pre- observatories are expected to have other sectors seems certain. vious telescope in the 10m wavelength facility AO systems (accompanied by range. Apart from its scientific value, laser guide stars) in the near future. The development program for SKA is which will include innovative studies This will, finally, allow near-diffrac- currently organized by a world-wide ranging from cosmology to climate tion-limited imaging in groundbased consortium of institutions. ASTRON research, LOFAR will be a forerunner astronomy. AO is essential for the next coordinates the SKA activities and the or prototype for SKA, although it will generation of extremely large tele- EU financing in Europe and partici- operate at lower frequencies and scopes, including OWL. Such tele- pates in coordinating global activities. therefore does not require low noise scopes with AO will be able to achieve Special attention is being given to optimization. It will be the first radio diffraction-limited imaging (without industrial spin-off and, through the telescope that employs aperture plane the need for laser guide stars) over all OECD and International Telecommu- detection and will thus provide multi- of the accessible sky. nications Union, to the selection and ple, independently pointed beams,

PART II. EXTRAPOLATION TO THE FUTURE 23 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

The Thousand 3.2.2.1. High energy Element Array astrophysics (X-rays) (THEA) tile. SRON is involved in technical R&D This world first studies for the next generation X-ray wide-band array detectors for ESA’s cornerstone mis- antenna is the sion XEUS. The present program is result of an strongly oriented towards optimiza- international R&D tion of single pixel micro-calorimeter program spon- performance. Recently a major mile- sored by NWO for stone was reached with respect to the the Square intrinsic physical performance of a Kilometer Array spectroscopy cell; a world record ener- (SKA). gy resolution of 3.9 eV for 5.9 keV X- Insert shows the rays is achieved, quite close to the the- test location in oretical limit. A major technical Dwingeloo where challenge is to build the single pixel 16 THEA tiles into an array device. With recent (2000) comprise a small funding through the NWO/GBE radio telescope grants program SRON has started the of a new genera- research and development of a 5x5 tion (courtesy pixel prototype imaging array of ASTRON). micro-calorimeters in close collabora- tion with the MESA+ institute at Twente University and a group in Fin- ESO’s design for OWL includes seg- expertise, combined with the expertise land. The collaboration with MESA+ is mented primary and secondary mir- resulting from the SINFONI program to develop Si-micro-machining pro- rors, integrated active optics and in NOVA (which includes significant cesses, required to produce the imag- multi-conjugate adaptive optics capa- research and system development in ing sensor array, while the collabora- bilities. The concept owes much of its AO) will likely provide the nucleus of tion with the Finnish group is to design design characteristics to features of AO expertise in the Netherlands. A and fabricate the cold, SQUID-based, existing telescopes, namely the joint effort between NOVA, TPD and read-out electronics. The level of effort Hobby-Eberly for optical design and ASTRON, if properly supported and within this collaboration is at present fabrication, the Keck for optical seg- coordinated, will help to return the approximately 12 fte and 150 kD/yr. mentation, and the VLT for system Netherlands to the forefront of astro- Additional funding in the order of 2 MD aspects and active optics control. The nomical instrumentation, will for this R&D program is expected to only critical area is multi-conjugate strengthen the expertise on astronom- become available through ESA’s adaptive optics, but its principles have ical instrumentation at the university research contracts for XEUS. recently been confirmed experimen- institutes, will allow participation in a tally. major next generation VLT AO instru- 3.2.2.2. Low energy ment, and will be a stepping stone in astrophysics The development of AO in the Nether- the development towards OWL. SRON’s goal is to participate in the lands has lagged behind the rest of the DARWIN mission at a significant level astronomical world. Given its impor- 3.2.2. At SRON with an emphasis on astrophysical tance, it is crucial that this situation is The medium-term program of SRON is imaging. In the time-frame 2001-2004, reversed as soon as possible. Two ini- basically governed by the choices a number of studies will be started tiatives have been taken recently: (1) made more than a decade ago. SRON’s related to (i) concepts for imaging large NWO-GBE approval for funding for technical R&D program is focused on fields, (ii) concepts for co-phasing the the AO assisted integral field spectro- development of new types of detectors whole interferometric array, (iii) end to graph OASIS on the WHT; (2) Found- for the high-energy radiation (X-rays) end modeling of the entire system, ing of an expertise center for adaptive and for the low-energy radiation (IR, (iv) design of a fringe detector for the optics in Delft by TNO-TPD, in coordi- submillimeter wavelengths). Both feasibility mission for Darwin called nation with NOVA. TPD is also devel- astrophysics and earth studies from SMART2. These studies will be carried oping a test adaptive optics system space will benefit from these develop- out in close collaboration with Leiden based on a state-of-the-art pyramid ments. These R&D programs are in Observatory, Delft University, TNO/ wavefront sensor. This development is close collaboration with technical uni- TPD, ESA and ESO. During the years extremely welcome, and the resulting versities. 2004-2006, SRON plans to be involved

24 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

in building a fringe detector for SMART2. Directly thereafter, signifi- cant work will be started on the actual design and implementation of SRON’s part of DARWIN. Attractive possibili- ties include the beam-combiner and a cryogenic instrument.

3.3. Coordinated approach in major new investments One of the strengths of Dutch astrono- my is the national coordination of the research, technical R&D, and instru- mentation programs between the uni- versities (NOVA) and the NWO insti- tutes ASTRON and SRON. All programs are complementary and each has sufficient critical mass in The Reflection Grating Spectrometer, order to make significant international built by SRON, is an integral part of the impact. large European X-ray satellite XMM- Newton. It analyses the X-rays coming The strategy is to terminate funding of from neutron stars, black holes and an existing observing facility when a other violent cosmic phenomena new one covering the same wave- (courtesy SRON). length interval comes into operation. Access to groundbased telescopes in lands in the coming decade. In addition regions that are obscured by up to 100 the northern and southern hemi- ASTRON searches for major addition- magnitudes of visual extinction. Its high sphere will remain a high priority al financial resources (~ 70 MD) outside angular resolution (0.01 arcsec to 1 arc- because of the need of follow-up work of NWO to realize LOFAR in the north- sec) in combination with its high sensi- of new discoveries from space obser- ern part of the Netherlands. tivity will allow applications in many vatories. other branches of astronomy as well. The present NOVA program (till mid Major new astronomical observing 2005) and its 2nd phase (2005–2010) ALMA will be an observatory of the facilities are international projects allows Dutch astronomy to make US, Europe and Japan. The required with time-scales of order 15-20 years. major contributions to ESO’s instru- financial contributions from the Ne- The investments must be accompa- mentation for the VLT and VLTI, as well therlands have to be made available nied by relatively modest national as to the R&D phase of ALMA. Contin- through the ESO subscription. The investments in computer-infrastruc- uation of the NOVA funding in its 2nd Netherlands will likely contribute to ture, database access, and software phase is essential to realize an impor- the following work packages for the developments in order to optimize the tant fraction of the new funding listed ALMA construction phase: (1) receiver scientific return of the investments in Table 4. cartridge of the 600-720 GHz frequen- and, at a level of 5% of these invest- cy band; (2) the future correlator. It ments, financial support for theoretical 3.3.1. Participation in ALMA would be natural to terminate the studies and model simulations. through ESO involvement in the JCMT when ALMA ALMA will push forward our under- starts its scientific operations. The Netherlands is amongst the small- standing in at least two of the three er member countries of ESO and ESA. research foci of NOVA. It will allow 3.3.2. ESO VLT-VLTI Rather than participating in many study of the formation and origin of instrumentation projects at the percentage of its gross high-redshift galaxies, of obscured Dutch astronomers receive about 6% national product, a major investment active galactic nuclei, of the disks of the observing time on the ESO tele- in well-selected new initiatives is pre- around young stars that can potentially scopes on La Silla, Chili, and the VLT ferred. Table 4 summarizes the priori- form planets, and of the envelopes of and VLT Interferometer at Paranal, ties. The major investments listed in old stars where the interstellar dust is Chili. ASTRON together with universi- the table amount to about 15% of the formed. In contrast to the most power- ty astronomers participated from an planned government spending on ful optical/near-IR telescopes such as early stage in the VLT instrumentation astronomical research in theNether- the HST or the VLT, ALMA can probe program and has worked with interna-

PART II. EXTRAPOLATION TO THE FUTURE 25 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

Table 4: Major investments in astronomy 2001 - 2010 NL share for funding in MD

Instrument Total New funding Remarks

1 ALMA participation through ESO 20 2 see table 4a Remarks 2 ESO VLT-VLTI instrumentation 12 6 see table 4b a. NL share: funding through NWO-G? 3 NGST mid-IR camera/spectrograph 7 7 a b. Financial contribution from NL astronomy 4 LOFAR / SKA preparation 7 7 b, c budget; ad hoc investments. 5 JIVE real time VLBI 9 3 d c. Total investment or order 70 MD with expected New initiatives 10 10 see table 4c major contributions from ICES, ICES-KIS, and international partners. Total 65 35 d. 30% NL share: funding through NWO-M?

Table 4a: specification ALMA participation 2001-2010 NL share in MD

Total New funding Remarks

NL contribution to construction costs 15.0 Through ESO subscription R&D for 650 GHz mixer 2.0 NOVA phase 1 R&D for Advanced Correlator 1.4 NWO-GBE+ ASTRON R&D for 2nd generation instrumentation 2.0 2.0 NOVA phase 2

Total 20.4 2.0

Table 4b: specification ESO VLT-VLTI instrumentation investments 2001-2010 NL share in MD

Total New funding Remarks

VLTI: MIDI 0.9 NOVA phase 1 + ASTRON VLTI: NEVEC 1.4 NOVA phase 1 VLT: VISIR 2.7 ASTRON VLT: OmegaCam for VLT Survey Telescope 1.8 NOVA phase 1 SINFONI 1.1 NOVA phase 1 2nd generation instrumentation 4.5 4.5 NOVA phase 2

Total 12.4 4.5

Table 4c: new initiatives instrumentation 2001-2010 NL share in MD

Total New funding Remarks

GAIA pm pm a Virtual observatory 2.5 2.5 b, c DOT pm pm d Next generation pulsar instrumentation 2.0 2.0 e ANTARES pm pm f New initiatives 5.5 5.5 g

Total 10.0 10.0

Remarks to table 4c c. NL participation in European program with major funding through EU. a. Fully funded through ESA. Possible NL participation through contracts d. Funding through NOVA, Universities, and grants line of NWO-GBE. with ESA. Link with wide-field imaging (OmegaCam; VISTA) and virtual e. Funding through NWO-GBE grants line, and/or NOVA phase 2. observatory. f. Funded physics program to demonstrate astrophysical applications. b. ICT infrastructure to explore giant databases produced by facilities like g. Reservation for 1-2 projects as follow-up of new discoveries/develop- OmegaCam, Vista, GAIA, and LOFAR. ments in 2006-2010.

26 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

Artist impression of ALMA,an array of 64 telescopes for (sub)-millimeter radiation. It will be jointly built by Europe, North America and Japan in the Chilean Atacama desert at 5000 meters altitude.The huge collecting area and interferometric capabilities will allow scientists to probe much deeper into the early universe (courtesy ESO).

tional partners to produce the VISIR stars in the universe, to trace the gene- for the Herschel Space Observatory. imager and spectrometer. When the sis and evolution of galaxies from their Within ASTRON, infrared instrumen- first phase of the NOVA program was formation to the present, and to deter- tation (VISIR, MIDI) has been devel- funded, Dutch astronomy became a mine the nature of luminous galactic oped for groundbased telescopes. The significant partner in the construction nuclei. NGST is expected to revolution- mid-IR spectrograph on NSGT pro- of several first generation VLT and ize our view of star- and planet-forma- vides a new excellent opportunity for VLTI instrumentations. While ESO’s tion in the galaxy. Dutch astronomers to continue and reward of the manpower contribu- extend a rich tradition in building tions through the allocation of guaran- As for the HST, ESA will participate in infrared instrumentation, in particular teed observing time is a well-appreci- NGST at the 15% level. The negotia- in spectroscopy. TPD/Delft is also very ated driver, the main argument to tions between NASA and ESA have interested to use its expertise and to invest further in the second generation been very favorable to Europe. Among participate in a Dutch hardware contri- VLT and VLTI instrumentation is to be other things, ESA will be responsible butions to NGST. The European contri- in the best position to exploit these for about half of the core instrument bution to the mid-IR instrument can be giant telescopes for scientific break- payload. The near infrared multi- split in 5 modules. Each of these is about throughs. object spectrograph will be funded by equal in size and effort. The cost of one ESA directly. Also, through special of these modules is estimated at 7 MD. The NOVA phase 2 instrumentation contributions from its member states, program will also be centered on ESO. ESA will take the responsibility for half There is considerable time pressure. It is expected to include wide-field of the mid-infrared instrument as well. Originally, the European contribution capabilities, the next step in the devel- to the mid-IR instrument was also opment of VLTI, and participation in a Dutch astronomers are particularly included in the ESA funding. However, second generation VLT instrument interested in the mid-infrared spectro- the total costs of the European contri- that builds on the expertise developed scopic capability of NGST which offers bution precluded this and, partly driv- in phase 1. the opportunity to study the chemical en by the UK commitment to a mid- lifecycle of dust from stellar outflows to infrared instrument, this effort was 3.3.3. Participation in the regions of star formation through the relegated to the membership coun- mid-infrared imaging characteristic fundamental vibrational tries. Active participation of the spectrograph of the NGST modes in the mid-infrared. Over the Netherlands in the design and con- NGST is a 6.5m infrared optimized last two decades, SRON has been struction of this instrument will safe- space telescope with at least an order involved in the IRAS/LRS and the guard the spectroscopic capabilities. of magnitude improvement in sensi- ISO/SWS spectrometers. Presently, In addition it will buy guaranteed tivity compared with the HST. It is SRON is the PI-institute for HIFI - the observing time proportional to the designed to detect light from the first submillimeter heterodyne instrument investments made.

PART II. EXTRAPOLATION TO THE FUTURE 27 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

3.3.4. LOFAR and SKA strategies allow deep imaging to history of the Milky Way, including the preparation almost as deep as connected element role of unseen matter. GAIA will con- SKA is planned to be two orders of interferometers like the WSRT. The tribute also to the detailed understand- magnitude more sensitive than exist- future of VLBI lies in higher sensitivity. ing of stellar interiors, will discover ing instruments, and will be able to The EVN is well placed in the short tens of thousands of planets around observe proto-galaxies so distant that term to achieve this with its present other stars, as well as many minor bod- they are still at the time before the main collecting area of the telescopes, and ies in the Solar system, and will provide epoch of galaxy formation. It will pro- its present recording rate of 1 Gbit/s the means for very accurate tests of vide new insights in the process of per station. Taking the wider band- General Relativity. galaxy building and galaxy evolution width recording available in Europe and will observe the development of into account, this means that the sensi- Participation in GAIA is attractive, as large-scale cosmic structure. SKA will tivity of the EVN will be 5 times that of the ESA budget covers the costs of uniquely be able to observe the effects the VLBA. The recent detection of both satellite and payload. SRON has of magnetic fields during star forma- three faint compact radio sources in interest in aspects of focal plane tion and in galaxy evolution. It will have the Hubble Deep Field with the EVN assembly, which builds on expertise enough instantaneous sensitivity to has demonstrated the promise of developed for XMM-Newton. Involve- measure rapidly scintillating radio extremely sensitive VLBI observa- ment in the (massive) data reduction sources, thereby providing an other tions. A further factor of five increase in effort would capitalize on the leading way of observing galaxies at micro- sensitivity is possible with current role taken by Dutch university groups arcsecond angular resolution. Fur- equipment, making detection of 30 in the analysis of large-scale imaging thermore, SKA will lead to the discov- microJansky sources relatively surveys such as DENIS, EIS, and in ery of tens of thousands of new pulsars straightforward. particular the OmegaCam project. in our Galaxy and in the local group galaxies, and will revolutionize our Even higher sensitivity to reach micro- 3.3.7. Promises in theory knowledge of neutron stars and black Jansky levels in continuum observa- One can distinguish between applied hole binaries. tions will be essential to keep pace with theoretical research that is closely con- developments in other regions of the nected to the interpretation of data, Scientifically, LOFAR is designed to be electromagnetic spectrum. This can and fundamental research that studies able to detect for the first time the sig- only be done by widening the band- basic physical processes operating in nature of the formation of the very first width of the data transported to the astronomical objects, or the methods stars and galaxies immediately after correlator using optical fibre links used in simulations. Dutch astronomy the Big Bang (the so-called epoch of re- and/or portable hard disks from the has a proven track record in the com- ionization). It will be unparalleled for telescopes to the correlator. The strate- putational astrophysics areas des- research in a wide spectrum of topics, gy is to develop both these possibilities cribed below. including solar and planetary physics, in conjunction with partners in the studies of starburst and active galaxies, USA at the Haystack Observatory, with The increase in computing power and atmospheric and ionospheric the EVN taking the lead in the fibre (both in CPU and in memory) allows research. developments, and Haystack taking more and more complex systems to be the lead in hard disk developments. studied such as (magneto) hydrody- The technologies required for these namics in more than one dimension astronomical instruments have paral- 3.3.6. GAIA and with radiative transfer, allowing lel developments in the commercial GAIA is ESA’s Cornerstone 6 Mission, for energy and momentum exchange ICT sector. Unlike the case with most foreseen to be launched around 2011. between radiation and fluid, and advanced scientific instrumentation, By scanning the entire sky about 100 involving non-linear particle-wave the commercial market is pushing sev- times to magnitude 20, it will deter- processes; realistic calculations are eral of the relevant technologies and mine distances and proper motions for now possible for flows with velocities there can in principle be close and about 1 billion objects in the Milky Way that reach the speed of light. fruitful collaboration with industry, and beyond, with a factor of 100 The gravitational interaction of large including substantial contributions by improvement in accuracy over the numbers of stars in clusters is industry. Hipparcos mission. It will also measure described by N-body dynamics, a field radial velocities and accurate photom- that is revolutionized by very efficient 3.3.5. Real time VLBI at JIVE etry. As a result, it will provide the special-purpose computers that make The techniques of VLBI have advanced three-dimensional motions of the stars it possible, e.g., to study the evolution dramatically in recent years. Wide field in the Galaxy, as well as their age and of globular star clusters and dense imaging at milli-arcsec resolution is metallicity distribution. This will allow galactic bulges surrounding one or readily possible and new calibration reconstruction of the entire formation more massive black holes. Effects of

28 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

Artist impression tion about the generation of the elec- of the Next tromagnetic radiation emitted by these Generation Space rapidly rotating neutron stars. Telescope, the successor to the The physics required to tackle all these Hubble Space problems is complex. It usually Telescope.To be involves the combination of different launched in 2009, fields of expertise, and a variety of com- it will have an putational methods. To master these 6.5-meter methods requires a long-term invest- primary mirror ment, especially in manpower. There and a large are many collaborations that often screen to block transcend the boundaries of astro- heat and light physics, involving scientists from plas- from the sun ma physics, oceanography and (courtesy applied mathematics. NOVA has Lockeed Martin). established a structure with the required size, diversity, and stability to keep Dutch theoretical astrophysics at the forefront of international research. However, additional investments in manpower and equipment are needed in the coming decade in order to keep up with increased activity in this excit- ing field abroad.

3.4. Coordinated approach in human resources Since many of the observing facilities are operated through international stellar evolution and of stellar mass agrees with many recent observations. organizations, astronomers have loss are now included in hybrid codes. Nevertheless, important details access to state-of-the-art telescopes Further development of such codes remain obscure such as the loss of independent of the location of their will be a research focus. angular momentum of proto-stellar research institute. Countries which clouds, the changes of the molecular are world-leading in astrophysical Numerical models for the structure of composition of the gas and the interac- research are - in principle - able to offer individual galaxies now predict accu- tion between gas and dust particles. their research institutes the latest- rately the stellar orbits and may be Similar problems are encountered in technology ICT infrastructure. Top- extended to calculate the effects of age starburst galaxies where the star for- researchers have a lot of freedom to and metallicity of the stellar popula- mation rate is exceptionally large and choose their home institute. Availabili- tions, something which to date has triggered by a rapid succession of ty of a stimulating research environ- been possible only for our own Galaxy. supernovae. ment, sufficient positions for junior Models for the interaction between permanent staff, postdocs and PhD systems now contain enough particles The acceleration of cosmic rays can students, and sufficient administrative to prevent numerical artefacts caused now be studied in detail in computer support staff are among the most by the discretisation of the mass distri- simulations that describe how particles important criteria on which they bution. In simulations of the large- propagate in the magnetic field in our choose to work in the Netherlands or scale structure of the early universe, own Galaxy or between galaxies. These elsewhere. In the coming decade the increased computational power models, often including Monte Carlo attracting and keeping world-leading will soon allow a meaningful compari- simulations, allow a comparison with scientists will be crucial for the Nether- son between the simulation and the the distribution observed at Earth. lands to maintain its forefront position observed distribution of luminous in astronomical research in a global matter in galaxies and clusters. Numerical simulations of radiative context. Because of its position strong plasmas in pulsar magnetospheres, position, Dutch astronomy is at pres- How stars form is a largely unsolved involving non-linear particle-wave ent able to attract sufficient numbers of problem. A global scenario exists that processes, yield important informa- the most promising young students. In

PART II. EXTRAPOLATION TO THE FUTURE 29 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

order to offer them an perspective suf- Table 5: Required development of research staff ficient position for PhD students and postdocs are required. It is therefore Number of research positions for astronomy in units of full time equivalents. The recommended - as shown in Table 5 - to present NOVA program will strengthen the university research in an environ- make major investments in human ment where the general trend is that the numbers of research positions in physi- resources in order to secure that out- cal sciences are declining. It is recommended to at least double the number of standing researchers will stay in the research positions for astronomy within the open competition grants program of Netherlands. NWO-GBE.

Funding resource Present Aim

Universities Permanent staff 50 52 Postdocs, PhD’s 56 70

NWO institutes Permanent staff 12 12 Postdocs, PhD’s 17 20

NWO GBE Postdocs, PhD’s 24 55

Other Permanent staff 1 1 Postdocs, PhD’s 20 25

Total 180 235

4. Concluding remarks

Astronomy in the Netherlands has cho- resources and access to state-of-the-art - Focus on technical R&D in four com- sen to focus its efforts in the coming observing and computing facilities. plementary areas, namely phased- decade on three related research areas array antennes for radio wavelengths which together constitute the overall Much of this ambition can be realised and optical/IR instrumentation for theme of the NOVA research strategy: within the present funding level for the VLT/VLTI at ASTRON, and X-ray The Life-Cycle of Stars and Galaxies. astronomy. About 40 MD of new detectors and IR interferometry for Maintaining world-ranking quality of resources are required in the period the next generation ESA space obser- research in this area requires contin- 2001-2010 (of order 8% of the existing vatories at SRON. ued access to state-of-the-art observ- budget). The coordinated approach ing facilities on the ground and in includes - New investments in a few well-cho- space, pro-active participation in deci- sen international projects, including sion making processes in ESO and - Continuation of the NOVA program ALMA, 2nd generation ESO ESA, and long term strategies of the in the period 2005--2010. VLT/VLTI instrumentation, mid-IR national institutes based on astronomi- spectroscopy on NGST, LOFAR and cal goals, a strong educational pro- - Expansion of the number of tempo- SKA preparation, and real-time VLBI gram, and the ability to attract and keep rary research positions supported by at JIVE. the most brilliant researchers by sup- the NWO Council for Physical porting them with sufficient human Sciences.

30 PART II. EXTRAPOLATION TO THE FUTURE ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010 Appendix: List of abbreviations

AAT Anglo Australian Telescope ING Isaac Newton Group (of the Roque de ALMA Atacama Large Millimeter Array los Muchachos Observatory on La ANTARES Astronomy with a Neutrino Telescope Palma) and Abyss environmental RESearch INT Isaac Newton Telescope AO Adaptive Optics Integral International Gamma-RAy Laboratory ASTRON Stichting Astronomisch Onderzoek in IRAM Institut de Radio Astronomie Nederland (Netherlands Foundation Millimetrique for Research in Astronomy) IRSI/Darwin Infrared Space Interferometer ATNF Australia Telescope National Facility ISO Infrared Space Observatory BeppoSAX Satellite per Astronomia in Raggi X JCMT James Clerk Maxwell Telescope BIMA Berkeley-Illinois-Maryland Associa- (on Mauna Kea, Hawaii) tion: array millimeter telescope JIVE Joint Institute for VLBI in Europe CCD Charge-Coupled Device JKT Jacobus Kapteyn Telescope CDN Canada Keck 10 meter Optical and Infrared CEA Center for Atomic Research in France Telescope on Hawaii CFHT Canada France Hawaii Telescope (on KPNO Kitt Peak National Observatory Mauna Kea, Hawaii) LISA Laser Interferometer Space Antenna Chandra X-ray Observatory (NASA) LOFAR Low Frequency Array CSO Caltech Submillimeter Observatory MIDI Mid-Infrared Interferometry (on Mauna Kea, Hawaii) Instrument for ESO’s VLTI CTIO Cerro Tololo Inter-American MkIV Mark IV Observatory in Chile MPIA Max Planck Institut für Astronomie GRID Global Resource Information Database (Heidelberg) DIMES Delft Institute of Microelectronics and NASA National Aeronautical and Space Submicron Technology Administration DOT Dutch Open Telescope NCA Nederlands Comité Astronomie ESA European Space Agency (Netherlands Committee for ESO European Southern Observatory Astronomy) EU European Union NEVEC NOVA-ESO VLTI Expertise Center EUV Extreme Ultra Violet NGST Next Generation Space Telescope EVN European VLBI Network NL the Netherlands FIRST Far InfraRed Submm Telescope (ESA NOVA Nederlandse Onderzoekschool Voor Cornerstone 4) now called HSO de Astronomie (Netherlands Research GAIA ESA’s Cornerstone 6 mission: School for Astronomy) Observatory for accurate positional NRL Naval Research laboratory and radial velocity measurements NWO Nederlandse organisatie voor GBE GebiedsBestuur Exacte wetenschap- Wetenschappelijk Onderzoek pen (NWO, Council for Physical OASIS Integral Field Spectrograph (for WHT) Sciences) OECD OESO - Organisatie voor Economische GMRT Giant Meter Radio Telescope (in India) Samenwerking en Ontwikkeling GTC Gran Telescopio Canarias OmegaCam Wide-field camera for the VST GRO Compton Gamma Ray Observatory OWL Over-Whelmingly Large optical HALCA Highly Advanced Laboratory for telescope Communications and Astronomy PI Principle Investigator HIFI Heterodyne Instrument for the PPARC Particle Physics and Astronomy Far-Infrared Research Council (United Kingdom) HIPPARCOS ESA’s astrometric satellite PUMA PUlsar MAchine (for the WSRT) HSO Herschel Space Observatory R&D Research and Development HST Hubble Space Telescope RXTE Rossi X-ray Timing Explorer ICES-KIS Interdepartementale Commissie SAURON Spectrographic Areal Unit for Economische Structuurversterking- Research on Optical Nebulae Kennis InfraStructuur (OC&W) SCUBA Submillimeter Common User Bolome- ICT Information and Communication ter Array Technology SINFONI Single Faint Object Near-infrared IF Intermediate Frequency Investigation

APPENDIX 31 ASTRONOMY IN THE NETHERLANDS strategy for 2001 - 2010

SIRTF Space Infrared Telescope Facility SKA Square Kilometer Array SMA Smithsonian Submillimeter Array SMART Small Missions for Advanced Research and Technology SOFIA NASA Airborn Observatory SRON Stichting Ruimte-Onderzoek Neder- land (Space Research Organization in the Netherlands) SRON-Astro Astronomy activities at SRON STW Stichting Technische Wetenschappen SWS Short Wavelength Spectrometer on ISO TNO Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderwijs TUD Technische Universiteit Delft UK United Kingdom USA United States of America UV Ultra Violet VISIR VLT Imager and Spectrometer for the mid-Infrared VISTA Visible and Infrared Survey Telescope VLA Very Large Array VLBA Very Large Baseline Array (US-VLBI network) VLBI Very Large Baseline Interferometry VLT Very Large Telescope (ESO) VLTI Very Large Telescope Interferometer (ESO) VST VLT Survey Telescope WHT William Herschel Telescope (part of ING) WSRT Westerbork Synthesis Radio Telescope XEUS X-ray Evolving Universe Spectroscopy Mission XMM-Newton X-ray Multi-mirror spectroscopy Mission

32 APPENDIX