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Home , Definition of planet, Pavel Kroupa, Photodissociation region, Taurus Molecular Cloud, Theta Tauri

THE FORMATION NEWSLETTER An electronic publication dedicated to early stellar/planetary evolution and molecular clouds No. 266 — 12 February 2015 Editor: Bo Reipurth ([email protected]) List of Contents

The Newsletter Interview ...... 3 My Favorite Object ...... 6 Editor: Bo Reipurth [email protected] Abstracts of Newly Accepted Papers ...... 12

Technical Editor: Eli Bressert Abstracts of Newly Accepted Major Reviews . 49 [email protected] New Jobs ...... 50 Technical Assistant: Hsi-Wei Yen Meetings ...... 52 [email protected] Summary of Upcoming Meetings ...... 58

Editorial Board

Joao Alves Alan Boss Jerome Bouvier Cover Picture Lee Hartmann Thomas Henning The cover shows an HST ACS image of the neb- Paul Ho ulous star LkHα 326, a young binary surrounded Jes Jorgensen by a bright reflection in the lower part of Charles J. Lada the image. Towards the top is the much fainter Thijs Kouwenhoven young star SSTc2d J033038.2+303212, which dis- Michael R. Meyer plays an edge-on disk and a tiny jet, oriented along Ralph Pudritz the ’chimney’ emanating from the star, apparently Luis Felipe Rodr´ıguez outlining an outflow lobe. Both are part of Ewine van Dishoeck a little aggregate of young low-mass stars, dubbed Hans Zinnecker ’Per 6’ in Rebull et al. (2007), and located in the small dark cloud Dobashi 4173 in the The Star Formation Newsletter is a vehicle for Perseus. North is approximately down and east ap- fast distribution of information of interest for as- proximately left. tronomers working on star and formation and molecular clouds. You can submit material Image credit ESA/NASA. for the following sections: Abstracts of recently accepted papers (only for papers sent to refereed journals), Abstracts of recently accepted major re- views (not standard conference contributions), Dis- sertation Abstracts (presenting abstracts of new Ph.D dissertations), Meetings (announcing meet- Submitting your abstracts ings broadly of interest to the star and planet for- mation and early community), New Latex macros for submitting abstracts Jobs (advertising jobs specifically aimed towards and dissertation abstracts (by e-mail to persons within the areas of the Newsletter), and [email protected]) are appended to Short Announcements (where you can inform or re- each Call for Abstracts. You can also quest information from the community). Addition- submit via the Newsletter web inter- ally, the Newsletter brings short overview articles face at http://www2.ifa.hawaii.edu/star- on objects of special interest, physical processes or formation/index.cfm theoretical results, the early solar system, as well as occasional interviews. Newsletter Archive www.ifa.hawaii.edu/users/reipurth/newsletter.htm

2 large projects or, for that matter, any project that did not involve the discovery of a new molecular species. To rem- Charlie Lada edy this, an informal consortium of Bell Labs, Harvard, in conversation with Bo Reipurth Columbia and Texas got together to build a millimeter- wave observatory (MWO) using an existing NASA dish at the McDonald Observatory. The members evenly split the observing time. The Harvard group was primarily in- terested in discovering new molecular species while I was solely interested in astronomical mapping and surveying. The was not optimized for molecular searches and that line of work turned out not to be that productive. But the MWO was a terrific survey telescope for mm-wave lines. As a consequence between 1973 and 1978 I was able to use most of the Harvard time to map molecular clouds. Two to three times a I traveled to McDonald for two-week long runs, observing around the clock. It was exhausting but it paid high dividends! It was the most exciting time of my career. Imagine, no observing propos- Q: Your PhD thesis in 1975 dealt with some of the first als, no TACs to deal with, just show up at the telescope, observations of molecular clouds. What was at that time exploit hot new technology and do interesting new science. the context for your thesis research? Q: Nearly 40 yrs ago at IAU Symp 75 in Geneva you and A: When I started on my thesis work in 1973, Bruce Elmegreen presented your model of sequential star were just beginning to be detected in emission in inter- formation. What was the genesis of this influential idea? stellar space. Most of the effort in those days was toward A: I was very influenced by the Annual Reviews article of discovering new molecular species. Not much was known Adriaan Blaauw on OB associations. In my thesis work about individual clouds themselves. The paradigm then on M17 and M8, I noticed that there was possibly a natu- was that molecular clouds were impurities within or, at ral extension of Blaauw’s age sequence of association sub- most, exotic appendages to HII regions. Since HII regions groups into molecular clouds. Shortly after I started my were acknowledged signposts of star formation, I guessed postdoc at the CfA I met with George Field and asked if that molecules might be important for star formation. I he or someone in his group would be interested in work- got the idea to try to determine the actual physical connec- ing with me to develop a theoretical framework for this tion between molecular and ionized gas within HII regions. idea. He sent me to Bruce Elmegreen, a recently arrived I think that one of the contributions of my thesis work was Junior Fellow at Harvard. I remember going to Bruce’s to reverse the existing paradigm by providing some of the office and outlining the observations that suggested trig- first evidence that molecular clouds were truly enormous, gering of star formation in M17, M8 and Orion and its rivaling OB associations in size and that HII regions were possible connection to Blaauw’s subgroups. I walked out in fact mere appendages to molecular clouds! Also the re- of Bruce’s office in a daze. Within two hours, sitting in sults of my thesis suggested that the diverse and seemingly front of me, he flushed out the bones of a complete the- unrelated signposts of star formation, such as OB and T oretical framework! Of course it took a few months to associations, HII regions, masers, HH objects, IR proto- put the flesh on those bones, but by the time of the first stars, etc., had one fundamental thing in common, they IAU Symposium on star formation in 1976 we had pretty all were physically associated with cold, massive, molec- much completed the work. I marshaled the observational ular clouds. This insight then led me to the notion that evidence, Bruce worked out the theoretical details–it was a these apparently disparate phenomena might actually be very effective and complementary scientific collaboration! manifestations of different evolutionary stages in a regular The symposium was exciting, as many of the giants of the star formation process operating within molecular gas. field such as Bok, Spitzer, Herbig and Larson were in at- Q: How did you get involved with millimeter-wave obser- tendance. And the most amazing part was that Blaauw vations that at the time were so very new ? was also there and was most encouraging about our work. A: I was very lucky to be in the right place at the right Q: Almost 30 yrs ago, at the IAU Symposium 115 in time. In the mid seventies there were only two Tokyo, you introduced the Class system for young stel- in the world that could observe CO: the NRAO 36-ft on lar objects, which has now become a fixture in our view of Kitt Peak and the 16-ft at McDonald Observatory. It was early . How did that originate? essentially impossible to get sufficient time at NRAO for A: That came about when I was in Arizona. My first grad-

3 uate student, Bruce Wilking, had just completed his thesis quent highly cited ARAA review on molecular outflows. work on the cluster embedded in the ρ Ophiuchi What are your reminiscences from those early efforts? cloud. He discovered many new and deeply embedded A: This story began for me at the MWO in the fall of members of the cluster. At the time the physical natures 1978 when Paul Harvey and I discovered extremely high of such infrared sources were unclear. Were they reddened velocity wings in the CO line toward the luminous infrared young OB stars, or some kind of mysterious young objects source AFGL 490. At that time only the famous Orion KL of unknown physical nature? We decided that to best source was known to exhibit such high velocity CO. Its address this question we needed to extend Bruce’s obser- origin was somewhat of a mystery with much speculation vations to longer wavelengths and obtain more complete about an embedded supernova as a possible cause. Unlike SEDs. We obtained 10µm observations of a large sample Orion, the high velocity gas in AFGL 490 appeared to be of these sources using the IRTF on Mauna Kea. When I partially resolved with the Texas antenna. Realizing that constructed their SEDs I noticed that they could be clas- resolved observations would provide critical constraints on sified by shape into three distinct groupings in what ap- the energetics and dynamics of the high velocity gas, we peared to be a progressive sequence of increasing circum- used the larger NRAO 11m telescope to obtain maps of stellar extinction. If I had read Lynden-Bell and Pringle, the source. I assigned an undergraduate student, Frank I would have instantly recognized that one of the SED Taylor, to work on the data and construct a spatial map groups (Class II) had the telltale signature of circumstel- of the emission in the line wings. He reported to me that lar disks, but that insight would come later. Bruce and I he was having difficulties doing this because of ”funny” published a preliminary sketch of this idea in 1984. But behavior of the line profile shapes. In the meantime Snell, it was in working with Frank Shu and Fred Adams that Loren and Plambeck had discovered the first bipolar out- the idea reached the more mature and familiar level that flow around L1551. Around that time I happened to visit I discussed in Tokyo in 1986. Luis Rodriguez at the control room of the 11m telescope Q: Can you elaborate some more about this collaboration? where he excitedly showed me observations of a new source A: Certainly, in anticipation of new qualitative results (Cep A) possessing both very high velocity wings and clear from the upcoming IRAS mission, Fred and Frank had bipolar morphology. I instantly realized that we were see- been working on a theory for predicting the infrared ap- ing the same thing in our observations of GL490, which I pearance of protostellar objects based on Frank’s early confirmed as soon as I got down from the mountain. At work on the collapse of singular isothermal spheres. Their this point I felt that we finally had enough new informa- work had a profound impact on my thinking about early tion to write a useful paper on GL490. In that paper we stellar evolution. In 1985 at a meeting at UC Santa Bar- noted the similarities between Orion, Cep A, GL490 and bara, Frank, Fred and I were exploring possible connec- L1551 and argued that energetic bipolar outflows could tions between their theoretical work and our observations. represent a common phase of early stellar evolution. It We found that with some tinkering Fred and Frank’s pro- became clear then that a survey of YSOs for outflow ac- tostellar models could fit the observations of the most em- tivity was needed. bedded (Class I) sources in Ophiuchus and quite Q: Is this when your collaboration with Bally started? well. However, these models failed to match the Class A: Yes. It turns out that to obtain the higher resolution II SEDs that characterized less embedded objects like T CO maps of GL490 I was given time both at the 11m tele- Tauri stars. Frank suggested that perhaps the dust ob- scope and at the newly operational FCRAO 14m antenna served in these objects resided in stable disks rather than in Massachusetts. A senior graduate student, John Bally, infalling envelopes. Since Fred’s protostellar models also was assigned to assist me at FCRAO. Technical problems included disks, removing the infalling envelopes in the foiled our attempts to obtain maps at FCRAO. However, code might enable them to reproduce the class II SED John later obtained a nice position-velocity map of the shapes. So Fred removed the infalling envelopes from the source that confirmed its bipolar nature and Paul and I models and they predicted quite accurately the observed included it in our paper. As a result of this interaction class II SEDs. Class II sources ( stars) were pro- John became quite interested in bipolar flows. In 1980 he tostars stripped of their infalling envelopes! And they had began a postdoc at Bell Labs and promptly discovered a disks! This discussion was the genesis of our 1987 paper CO outflow in NGC 2071. Shortly thereafter we decided to on the spectral evolution of young stellar objects and it combine efforts and perform an extensive survey for out- provided the needed theoretical framework for the classi- flows around known YSOs using both the 11m telescope fication scheme I presented in Tokyo. and the 7m Bell Labs antenna. That led to the Bally and Q: After the discovery of fast molecular outflows, you em- Lada paper which was published in 1983. During those barked on detailed studies of these phenomena, including (1980-1984) outflow studies really exploded and I the famous Bally-Lada paper from 1983, and your subse- was invited to summarize and synthesize these develop-

4 ments for an Annual Reviews article which appeared in mary of the prior research in the field. This would have 1985. In the end I think these papers together made a been a much more difficult task if one were reviewing a compelling case that Snell, Loren and Plambeck’s obser- more mature subject matter. vations of L1551 marked the discovery of a fundamentally Q: In brother-sister research teams are very important new phase of star formation. The fact that this rare. The Herschels being the most famous example. What discovery was completely unanticipated by theory is the do you consider the scientific highlights of your joint work true measure of its profound astrophysical significance. with Liz Lada? Q: You and Nick Kylafis organized two memorable NATO A: Well one of them is following in the footsteps of the Advanced Study Institute meetings in Crete in 1990 and Herschels who discovered and cataloged dark nebulae (Holes 1998. These had a profound effect on those of us who at- in the Heavens) and more than 200 years ago even spec- tended, and a long-lasting impact through the proceedings. ulated on the origin of clusters from these celestial va- A: I consider the organization of these two meetings with cancies! Besides the writing of the ARAA article, other Nick to be among the most rewarding things I have done highlights include the work with Liz and her student Karl in my astronomical career. The origin of these meetings Haisch on L band imaging of clusters. That effort culmi- can be traced to a lunch I had in 1987 with Nick at a nated in the highly cited paper constraining the lifetimes conference on star formation. At that lunch we discussed of circumstellar disks. Obtaining these observations from ways to improve the educational impact of NATO ASIs. the ground was quite challenging, yet the results have held We found we agreed on the basic principles and decided to up quite well. Next was the imaging study of IC348 that try to put them into practice by organizing and conduct- led to modeling K-band functions of clusters ing our own NATO ASI on star formation. Briefly, from to constrain their IMFs with Liz’s student Gus Muench. among the most accomplished researchers in the field, we Besides supporting the idea of a universal IMF, this work decided to select lecturers with reputations as excellent resulted in the first measurement of a substellar IMF (in communicators. Second, we needed to insure that these Orion) and showed that brown dwarfs were not a major lecturers prepared rigorous, pedagogical review lectures reservoir of mass in young clusters. Third was the develop- aimed at the graduate student level. These lectures then ment of the NICE technique to measure and map extinc- could form the basis of proceedings that could serve as a tion in molecular clouds using wide-field infrared imaging reference book for a graduate course or seminar in star devices. This technique lead to a whole new avenue of formation. Third, it was important to provide ample time productive research. It was a major advance in producing for interactions between lecturers and students, for poster accurate measurements of the basic cloud properties. sessions, and for fun and recreation. Finally, we needed to Q: Can you say some more about the development of NICE? find a highly desirable venue for the meeting. A resort in Crete seemed like the perfect setting especially since Nick A: It was born from the ashes of an unsuccessful project, was based there and could handle the local organization. with Liz, Dan Clemens and John Bally, designed to reveal and study a large population of T Tauri stars in the dark Q: Your most cited paper, with more than 1300 citations, cloud associated with IC 5146. Despite an extensive in- is the 2003 ARAA review by you and Liz Lada on ”Em- frared imaging survey detecting more than 4000 stars, only bedded Clusters in Molecular Clouds”. What is the secret a handful turned out to be new PMS stars. Hardly enough behind such a major impact in the community? to be interesting. It was hard to contemplate abandoning A: First, and foremost, is the subject matter. Second, the project after so much effort was expended on it. Could perhaps, is the approach Liz and I adopted for writing something interesting be done with good infrared photom- the review. We basically followed the template developed etry of 4000 stars? Within a couple of months, Liz and for my 1985 ARAA review on outflows. The goal was to I could∼ answer in the affirmative with the development of provide a first synthesis of a relatively new research area NICE to produce the first truly deep and accurate extinc- derived from a thorough review of work performed in that tion map of a . However, our work in this area up to that time. The idea was that, by assembling area is where it is today because of my former student and taking stock of the most pertinent existing informa- Jo˜ao Alves. He recognized the potential of the method tion about the topic under review, one might be able to and successfully applied it to additional clouds in his PhD derive new insights that would advance the field. This thesis and then later as a postdoc when he produced the was possible in both instances because the research topics beautiful study of B68. The NICE method was fundamen- being reviewed were very new, highly interesting and in a tally improved when Marco Lombardi joined our team and period of rapid growth. They were not yet fully developed developed the NICER and NICEST algorithms. This en- and the broad implications for astronomical science were abled extinction mapping of clouds on an almost industrial not yet clear or fully understood. As a result we were in a scale using 2MASS data. After two productive decades, position to contribute something beyond a straight sum- mapping infrared extinction still keeps us all busy.

5 My Favorite Object The Class 0 Protostar L1527 IRS John Tobin

The dark cloud L1527 (Lynds 1962) lies within the Heiles Cloud 2 region of the Taurus molecular cloud at a dis- Figure 1: False-color IRAC image of L1527 IRS (IRAS tance of 140 pc. The first hint of a protostar within 04368+2557) at 3.6 µm (blue), 4.5 µm (green), and 8.0 µm ∼ L1527 was found by Frerking et al. (1982), with a tenta- (red) from Tobin et al. (2008). Image is 200′′ ( 28,000 tive outflow detection in a 12CO (J = 1 0) spectrum. ∼ → AU) on a side. The outflow is in the east-west direction, in Definitive evidence for a protostar came from the Infrared the same direction as the bow tie-shaped scattered light Astronomy Satellite (IRAS), where a source was detected structure. The protostar is located at the center of the at 25 µm, 60 µm, and 100 µm (IRAS 04368+2557; Beich- image, between the two scattered light cavities. man et al. 1986). Thus, the protostellar system is now commonly referred to as L1527 IRS. The IRAS detection led to many additional observational studies of the source including mapping (Benson & Myers 1989), far- strated that the nebulae of L1527 and other sources were infrared and submillimeter mapping (Ladd et al. 1991ab), consistent with light from the protostar and disk scatter- and near-infrared imaging (Tamura et al. 1991). The bolo- ing on dust grains in and along outflow-evacuated bipo- lar cavities. This was an important development in the metric luminosity of the system is 2 Lsun (Ladd et al. 1991a) and the ratio of submillimeter∼ luminosity to bolo- understanding of protostellar structure. It is now known metric luminosity was 0.007, making L1527 IRS a Class that scattered light in the outflow cavities (e.g., Whitney 0 protostar, the youngest class of protostars (Andr´eet al. et al. 2003) is responsible for much of the emergent flux 1993). These early studies laid the groundwork for our cur- at wavelengths shorter than 10 µm toward low-mass pro- rent understanding of L1527 IRS, and many of aspects of tostars. Outflow cavities are the reason that many Class the star formation process can be observed toward L1527 0 protostars can be detected at wavelengths shorter than IRS (rotation, infall, outflow, and disk formation) making 10 µm. This is illustrated in the beautiful Spitzer IRAC it an ideal testing ground for star formation theory. images obtained toward L1527 IRS and shown in Figure 1 (Tobin et al. 2008); the outflow is oriented in almost ex- actly the east-west direction. The early near-infrared im- 1 The SED and Envelope ages of L1527 captured only the eastern side of the nebula (Tamura et al. 1991, Kenyon et al. 1993), because it is brighter than the western side at 2.2 µm and shorter wave- The proximity of L1527 IRS and its bright emission in lengths. The illumination of the scattered light nebulae is the far-infrared and submillimeter enabled its spectral en- also known to vary in intensity, and the east and west sides ergy distribution (SED) to be well-characterized soon after of the nebulae can fade or brighten independently (Tobin its discovery. Thus, it was part of the radiative transfer et al. 2008). modeling study of Taurus protostellar systems by Kenyon, Calvet, & Hartmann (1993a). Furthermore, L1527 IRS The fantastic Spitzer observations of L1527 IRS motivated was known from Tamura et al. (1991) to show extended us to revisit the modeling of the source in Tobin et al. emission at 2.2 µm, and Kenyon et al. (1993b) demon- (2008). We employed the Monte Carlo radiative equilib-

6 (Delamarter et al. 2000).

Figure 2: Model SED of L1527 IRS generated with the Whitney et al. (2003) radiative transfer code overlaid on the multi-wavelength photometric data (Tobin et al. 2013). The photometry and IRS spectrum are taken from Tobin et al. (2008) and references therein. Photome- try taken with apertures of 71.′′4 (diamonds) and 7.′′14 (boxes) (10000 AU and 1000 AU) are plotted. The trian- gle at 3.8 µm is the Gemini L′ flux within 1000 AU. The model SEDs are plotted for apertures of 10000 AU (black line) and 1000 AU (gray line). The model is somewhat de- ficient in flux at long wavelengths; however, this depends on both the level of external heating (which is not con- sidered) and the large-scale density profile and envelope + Figure 3: Mapping of N2H line emission toward L1527 structure. IRS (Tobin et al. 2011). The top row shows the data from the IRAM 30m and the bottom row shows the CARMA data. In the left column, the 8 µm IRAC images are + rium and scattered light code of Whitney et al. (2003) to shown with N2H (J = 1 0) integrated intensity con- → + model both the IRAC images and the SED of the source. tours overlaid. The line-center velocity fit of the N2H The observed SED is shown in Figure 2, along with the emission across the envelope are shown in the right col- model SED from Tobin et al. (2013). The high surface umn. The IRAM 30m contours start at 5σ with 10σ in- brightness of the cavities at IRAC wavelengths required a tervals; the CARMA contours start at 3σ with 3σ in- ± dust opacity model with a dust grain size distribution up tervals. The single-dish velocity field appears to have a to 1 µm in radius to be used in modeling. A dust grain component along the outflow and normal to it. The inter- size distribution only going up to 0.25 µm in radius (typi- ferometer velocity maps reflect the single-dish velocities cal for dust) could not reproduce the on the largest scales, but near the protostar the small- intensity of the observed scattered light. The dust opac- scale velocity gradient is in the opposite direction of the ity model with larger grains increased the scattered light large-scale gradient. The blue and red arrows correspond between 3.6 µm and 8.0 µm without substantially affect- to the outflow directions and the black arrows correspond ing the sharpness of the 10 µm silicate feature. However, to the velocity gradient directions. the modeled surface brightness was still a bit low, but this could be rectified by adding a small amount of dust to the cavity. The point source at the center was also difficult While the SED enabled the luminosity and envelope prop- to reproduce and in the end we adopted a two-component erties of the source to be characterized, molecular line outflow cavity model to reproduce the feature. This con- observations were needed to examine the envelope kine- figuration had an inner, narrow cavity and a wider cavity matics. Benson & Myers (1989) mapped the envelope offset along the outflow direction. The physical motiva- around L1527 IRS in NH3 (1,1) emission and Goodman et tion for this structure is that a flattened envelope could al. (1993) used these data to characterize the kinematics constrict the outflow near the equatorial plane and then of the envelope around L1527 IRS. They found a velocity −1 −1 opening more widely in the lower density polar regions gradient in the north-south direction (3.3 km s pc ; ω

7 + dient reversal in N2H emission from 1000 AU scales to 10000 AU scales, consistent with the results from Ohashi et al. The velocity gradient reversal is a clear indication the envelope-scale kinematics do not necessarily reflect ro- tation. My preferred explanation is that the larger-scale that velocity gradient originates from projected infall mo- tions in an asymmetric envelope (Tobin et al. 2012a). There are several hints of the envelope being asymmetric. The submillimeter maps of the envelope (e.g., Chandler & Richer 2000) show the envelope to be more extended on the north side, in agreement with the 8 µm extinction maps and outline of the envelope in diffuse scattered light (Tobin et al. 2008, 2010a). The outline of protostellar envelopes or dark clouds in diffuse scattered light is now commonly referred to as ‘coreshine’ (Pagani et al. 2010). Thus, projected infall motions in an asymmetric envelope could be a plausible explanation. Most importantly, the velocity gradient reversal in L1527 IRS shows that one must be cautious in the interpretation of velocity gradients as rotation, from which the specific angular momentum is Figure 4: Gemini-North L′ (3.8 µm) image of L1527 IRS inferred. (Tobin et al. 2010b). The signature of an edge-on disk is apparent, the bright features separated by the dark lane, in addition to the outflow cavity. The outflow cavity rapidly widens about 6′′ (840 AU) from the protostar. 2 The Disk

Recent interest in L1527 IRS has been centered around its disk and inner envelope properties. Aside from a bipolar −13 −1 = 10 s ). This is orthogonal to the outflow direction, outflow, the first direct evidence for a disk around L1527 but the outflow was not mapped until later (Bontemps IRS was found by Loinard et al. (2002). They detected a et al. 1996, Tamura et al. 1996). Furthermore, Myers disk-like structure in the 7 mm continuum with the VLA et al. (1995) detected a signature of infall toward L1527 at a resolution of 0.′′085 0.′′066 ( 10 AU). This struc- × ∼ IRS in single-dish spectra of H2CO and C3H2 molecular ture was 40 AU in diameter and only detected at the 4σ transitions. level; however,∼ it was extended orthogonal to the outflow Ohashi et al. (1997) examined kinematics of the inner as expected for a disk, given that the system was already envelope of L1527 IRS with spatially-resolved C18O and thought to be viewed nearly edge-on. Corroborating ev- 13CO (J =1 0) observations using the Nobeyama Mil- idence for a disk was found in unpublished BIMA 3 mm limeter Array.→ They found clear evidence for rotation and data taken in all array configurations (Y. Shirley, private infall in the inner envelope and these data led Ohashi et al. communication). These data showed evidence for flatten- to estimate the mass of the protostellar object to be 0.1 ing of the visibility amplitudes at baselines longer than ∼ Msun. Furthermore, an often overlooked result from this 100 kλ, a signature of compact structure. 18 study was that the velocity gradient from the C O enve- The first sensitive, high-resolution study of L1527 IRS at lope is in the opposite direction as was observed in NH3 1.3 mm was published by Maury et al. (2010), having by Goodman et al. (1993). If interpreted as rotation, this 0.′′5 0.′′3 resolution with the PdBI. L1527 did appear would imply that the outer envelope was counter-rotating marginally∼ × resolved in this study, but the beam was ex- with respect to the inner envelope. tended in the north-south direction, the same position an- + We recently mapped the envelope of L1527 IRS in N2H gle as the extended structure detected by Loinard et al. (J =1 0) with the IRAM 30m telescope and the Com- 2002). Thus, the disk-like structure was not prominent bined Array→ for Research in Millimeter-wave Astronomy enough in those data to be emphasized. (CARMA; Tobin et al 2011), see Figure 3. Similar kine- Around the same time as the work by Maury et al. (2010) matic features are evident in the new map as in Goodman was published, we received Gemini-North L′-band (3.8 et al. (1993), but with 3 better resolution and better ′′ × µm) observations of L1527 at 0 .3 resolution in natural sensitivity/sampling. The multi-scale view of the kine- seeing conditions (Figure 4). We were attempting to re- matics enabled us to definitively reveal the velocity gra- solve the point-like structure observed between the out-

8 around L1527 IRS, but without kinematic data, a Keple- rian disk could not be confirmed despite the obvious phys- ical appearance. To examine the kinematics on the scales of the disk, we observed the 13CO (J = 2 1) transition toward L1527 IRS with CARMA in C and→ D configurations. These data showed a clear signature of rotation on the scale of the disk (Figure 6). While the data only had 1′′ resolution, signal to noise was high enough in the 13CO∼ line to fit the rotation curve and determine that it was consistent with a Keplerian rotation. We were then able to measure the mass of the protostar, finding it to be 0.2 Msun (Tobin Figure 5: High-resolution continuum images of L1527 IRS et al. 2012b). This was the first convincing∼ detection of from the SMA at 870 µm (left) and CARMA at 3.4 mm a Keplerian disk around a Class 0 protostar and the first (right) (Tobin et al. 2013). The contours in all images time a protostellar mass was measured for such a young start at 3σ and increase in 3σ intervals; σ = 5.0 mJy object. With a protostar mass that small, stellar structure −1 −1 beam (SMA), and 0.24 mJy beam (CARMA). Both models only indicated a luminosity of 0.3 Lsun from the the 870 µm and 3.4 mm data are extended normal to the protostar itself. The system luminosity was modeled to be ′ outflow direction, consistent with the dark lane in the L - 2.75 Lsun (Tobin et al. 2010b), therefore nearly 90% of band image, consistent with an edge-on disk. the luminosity must be coming from disk onto the protostar. ALMA Cycle 0 data for several other protostars were forth- flow cavities with Spitzer (Figure 1). The L′ image is coming shortly after the disk detection around L1527 IRS. strikingly reminiscent of the ob- Thus, several additional Class 0 disks have now been dis- servations of HH30 (Burrows et al. 1996) and the Taurus covered (Murillo et al. 2013, Lee et al. 2014, Codella Class I protostars (Padgett et al. 1999). Prior to obtain- et al. 2014; Lindberg et al. 2014). Furthermore, L1527 ing these data, we thought the point-like source could be IRS itself was observed by ALMA in Cycle 0 by Ohashi the product of outflow-envelope interaction. However, we et al. (2014) and Sakai et al. (2014a,b). Ohashi et al. recognized that the modified outflow cavity structure ap- (2014) observed L1527 IRS in C18O (J =2 1), finding → proximated the upper layers of a highly-flared disk. These a similar velocity structure as we observed in 13CO, but data, along with the resolved 7 mm image from Loinard with about 5 better signal-to-noise. Their analysis found × et al. (2002) and the marginally-resolved structure at 1.3 that the rotationally-supported region of the disk began mm from Maury et al. (2010), all pointed to the presence at R = 54 AU, with a corresponding protostar mass of of a disk around L1527 IRS; our model of the resolved 0.3 Msun. Given the substantially better quality of the scattered light indicated a disk radius of 180 AU (Tobin kinematic data from ALMA, the consistency between the et al. 2010b). two datasets is quite good. The Gemini result motivated us to undertake a more de- Sakai et al. (2014a,b) observed L1527 IRS in other molec- tailed characterization of the disk. This required obser- ular line tracers, focusing on the carbon chain molecules vations of L1527 IRS at the highest possible resolution at that were known to be present in the envelope from its millimeter and sub-millimeter wavelengths, using the Sub- warm carbon-chain chemistry (WCCC; Sakai et al. 2009). millimeter Array (SMA) in Very Extended configuration The c-C3H2 (along with CS and CCH) trace the at 870 µm and CARMA at 3.4 mm in A configuration. The inner envelope velocity structure, a beautiful example of millimeter and submillimeter data were needed to trace rotation with infall down to a radius of 100 AU, where ∼ the bulk of the disk material in the midplane since the emission abruptly cuts off (Figure 7). At scales smaller scattered light only traced the upper layers. The contin- than 100 AU, emission from the SO molecule becomes uum images are shown in Figure 5 and both observations quite strong, with the dominant kinematic feature being a resolve a disk-like structure in the north-south direction, linear velocity gradient, indicative of the emission coming consistent with the dark lane from the L′ image. The SMA from a narrow range of radii at about R 100 AU. There ∼ data had 0.′′28 resolution while the CARMA data had is also some higher-velocity emission that may be consis- 0.′′35 resolution∼ and the disk-like structure had an ap- tent with a Keplerian rotation, but no emission from radii ∼parent radius of 90 AU. The resolved millimeter emission greater than 100 AU. This was interpreted as a possible at multiple wavelengths, in conjunction with the scattered chemical change due to an accretion shock going from the light image, were strong evidence for something disk-like inner envelope to the disk as the material encounters a

9 Figure 6: 13CO emission from the inner envelope and disk around L1527 IRS exhibiting a Keplerian rotation signature (Tobin et al. 2012b). The CARMA 1.3 mm continuum image is shown (grayscale) with the red and blue contours showing 13CO emission integrated at low velocities (left), intermediate velocities (middle), and high velocities (right). The white cross in all panels marks the location of the protostar. The blue and red-shifted emission centroids show a clear signature of rotation on the size-scale of the protostellar disk and no extension of emission along the outflow. The low-velocity emission likely includes contributions from the envelope, while the intermediate to high-velocity emission is likely dominated by the disk. The contours start and increase in intervals 3 times noise level (σ) where σ = 0.85 K km s−1 (red) and 0.75 K km s−1 (blue). The beam is shown in the lower right corners, 1.1′′ 0.95′′. ×

centrifugal barrier. Only the H2CO molecule was found gestion of multiplicity was from 800 µm continuum maps, to trace emission from both the inner infalling envelope finding another submillimeter peak located 20′′ northwest and the disk (Sakai et al. 2014b). The universality of of L1527 IRS (Fuller et al. 1996). However, later sub- such chemical changes and SO emission from the outer millimeter mapping by Chandler & Richer (2000) with edge of protostellar disks is still under investigation, but SCUBA did not find another discrete source, but they did it points to a possible method for picking disks out of their find that the submillimeter emission is extended along the infalling envelopes. It is noteworthy that the other WCCC outflow. Thus, spatial filtering and perhaps incomplete source IRAS 15398-3359 does not show a similar chemical sampling by the previous observations could explain the structure (Oya et al. 2014); however, that source may be apparent false detection. less-evolved. Another indication of multiplicity was found by Loinard L1527 IRS is currently the only Class 0 disk for which the et al. (2002) with the VLA at 7 mm. A candidate com- magnetic field morphology has been examined. Segura- panion separated by 0.′′17 (24 AU) was detected, with Cox et al. (2015) observed dust polarization with CARMA apparent proper motion of the companion source relative at 1.3 mm, finding magnetic field vectors aligned with the to a dataset taken 5 years prior. Thus far no millime- disk plane. This is indicative of toroidal magnetic fields in ter/submillimeter observation has had high enough reso- the disk midplane, consistent with models for angular mo- lution to independently confirm this companion. However, mentum transport by magneto-rotational instability. The Melis et al. (2015 in prep.) observed L1527 IRS with the lack of a poloidal magnetic field component could be evi- upgraded VLA and did not find evidence for the compan- dence against disk winds transporting angular momentum, ion, despite much higher sensitivity. Thus, the current ev- but the field morphology in the disk upper layers (where idence seems to point toward L1527 being a single source winds are launched) could be different from that of the at least down to 10 AU scales. midplane. ∼ 4 Summary 3 Multiplicity While L1527 has already revealed many of its riches, there There have been a few claims of multiplicity in the L1527 will certainly be new things to learn with upcoming ALMA IRS system, which is important when considering the lu- data and some surprises are probably still in store as well. minosity generation of the system as well as the properties The positive identification of the disk around L1527 and of the outflow, disk, and perhaps chemistry. The first sug- now other Class 0 sources are giving us a first glimpse of

10 Figure 7: ALMA integrated intensity maps (left) of the c-C3H2 emission (color scale) and SO emission (contours); modified from Figure 1 of Sakai et al. (2014a). The middle panel show a position-velocity (PV) diagram of c-C3H2 emission, exhibiting a signature of rotation and infall, until a radius of 100 AU where the emission cuts off. A PV diagram of SO emission is shown in the right panel, having a bright linear∼ velocity gradient, indicative of the emission being concentrated in a ring at the outer disk radius. This is hypothesized to reflect an accretion shock at the outer edge of the disk where c-C3H2 is destroyed and SO is released from the dust grain surfaces. There is also faint SO emission extending to higher velocities, consistent with Keplerian rotation. The beam is plotted in the upper left corner of the integrated intensity maps.

the beginning of proto-planetary disk evolution. However, Frerking et al. 1982, ApJ, 256, 523 there is still work to be done in understanding the disk and Fuller, G.; Ladd, E. F.; Hodapp, K.-W. 1996, ApJ, 463, 97 Kenyon, S.; Calvet, N.; Hartmann, L. 1993a, ApJ, 414, 676 envelope around L1527 IRS. The reason for the chemical Kenyon, S. et al. 1993b, ApJ, 414, 773 change at the outer edge of the disk needs to be charac- Ladd, E. F. et al. 1991a, ApJ, 366, 203 terized and determine if it is a feature common to many Ladd, E. F. et al. 1991b, ApJ, 382, 555 protostars. The size of the Keplerian region also needs Lee,C.-F., et al. 2014, ApJ, 786, 114 Lindberg, J. E., et al. 2014, A&A, 556, 74 further investigation; Ohashi et al. (2014) just barely re- Loinard, L. et al. 2002, ApJL, 581, 109 solve the turnover and the SO emission may suggest that Lynds, B. 1962, ApJS, 7,1 a larger rotationally supported disk is possible. To this Maury, A. J., et al. 2010, A&A, 512, 40 end, I am looking forward to my ALMA H13CO+ and Melis, C. et al. 2015, in prep. 13 Murillo, N. et al. 2013, A&A, 560, 103 H CN data. We are aiming to characterize the disk rota- Myers, P. C. et al. 1995, ApJ 449, 65 tion curve with more optically thin, higher critical density Ohashi, N. et al., 1997, ApJ, 475, 211 tracers than the CO isotopologues. Ohashi, N. et al., 2014, ApJ, 796, 131 Oya, Y. et al. 2014, ApJ, 795, 152 I would like to thank all my collaborators on the various Padgett, D. et al., 1999, AJ, 117, 1490 papers that we have published on L1527 over the years and Sakai, N. et al. 2014, Nature, 507, 78 the great fun we have had in examining this protostellar Sakai, N. et al. 2014, ApJ, 791, 38 Segura-Cox, D. et al. 2015, ApJL, 798,2 system! Pagani, L., et al. 2010, Science, 329, 1622 References: Tamura, M., et al. 1991, ApJ, 374, 25 Andr´e, P. et al. 1993, A&A, 406, 122 Tamura, M. et al. 1996, AJ, 112, 2076 Beichman, C. A. et al. 1986, ApJ, 307, 337 Tobin, J.J. et al. 2008, ApJ, 679, 1364 Benson, P. J. & Myers, P.C. 1989, ApJS, 71, 89 Tobin, J.J. et al. 2010a, ApJ, 721, 1010 Bontemps, S. et al. 1996, A&A, 311, 858 Tobin, J. J., Hartmann, L., & Loinard, L. 2010b, ApJL, 722, 12 Burrows, C. J et al. 1996, ApJ, 473, 437 Tobin, J.J. et al. 2011, ApJ, 740, 45 Chandler, C. & Richer, J., 2000, ApJ, 530, 851 Tobin, J.J. et al. 2012a, ApJ, 748, 16 Codella, C. et al. 2014, A&A, 586, 5 Tobin, J.J. et al. 2012b, Nature, 492, 83 Delamarter, G.; Frank, A.; & Hartmann, L. 2000, ApJ, 530, 923 Tobin, J.J. et al. 2013, ApJ, 771, 48 Goodman, A. et al. 1993, ApJ, 406, 528 Whitney, B. A., et al. 2003, ApJ, 591, 1049

11 Abstracts of recently accepted papers

Formation of prestellar cores via non-isothermal gas fragmentation S. Anathpindika1 1 Indian Institute of Science, Bangalore, India E-mail contact: sumed k at yahoo.co.in Sheet-like clouds are common in turbulent gas and perhaps form via collisions between turbulent gas flows. Having examined the evolution of an isothermal shocked slab in an earlier contribution, in this work we follow the evolution of a sheet-like cloud confined by (thermal) and gas in it is allowed to cool. The extant purpose of this endeavour is to study the early phases of core-formation. The observed evolution of this cloud supports the conjecture that molecular clouds themselves are three-phase media (comprising viz. a stable cold and warm medium, and a third thermally unstable medium), though it appears, clouds may evolve in this manner irrespective of whether they are gravitationally bound. We report, this sheet fragments initially due to the growth of the thermal instability and some fragments are elongated, filament-like. Subsequently, relatively large fragments become gravitationally unstable and sub-fragment into smaller cores. The formation of cores appears to be a three stage process : first, growth of the thermal instability leads to rapid fragmentation of the slab; second, relatively small fragments acquire mass via gas- accretion and/or merger and third, sufficiently massive fragments become susceptible to the gravitational instability and sub-fragment to form smaller cores. We investigate typical properties of clumps (and smaller cores) resulting from this fragmentation process. Findings of this work support the suggestion that the weak velocity field usually observed in dense clumps and smaller cores is likely seeded by the growth of dynamic instabilities. Simulations were performed using the smooth particle hydrodynamics algorithm. Accepted by Pub. of Astron. Soc. of Australia (PASA) http://arxiv.org/pdf/1501.01401

Stability of filaments in star-forming clouds and the formation of prestellar cores in them S. Anathpindika1 and J. Freundlich2 1 Indian Institute of Science, Bangalore, India 2 LERMA, Observatoire de Paris, CNRS, 61 av. de l’Observatoire, 75014 Paris, France E-mail contact: sumed k at yahoo.co.in It is now widely accepted that dense filaments of molecular gas are integral to the process of stellar birth and poten- tial star-forming cores often appear embedded within these filaments. Although numerical simulations have largely succeeded in reproducing filamentary structure in dynamic environments such as in turbulent gas and while analytic calculations predict the formation of dense gas filaments via radial collapse, the exact process(es) that generate/s such filaments which then form prestellar cores within them, is unclear. In this work we therefore study numerically the formation of a dense filament using a relatively simple set-up of a uniform-density cylinder in pressure equilibrium with its confining medium. In particular, we examine if its propensity to form a dense filament and further, to the formation of prestellar cores within this filament bears on the gravitational state of the initial volume of gas. We report a radial collapse leading to the formation of a dense filamentary cloud is likely when the initial volume of gas is at least critically stable (characterised by the approximate equality between the mass line-density for this volume and its maximum value). Though self-gravitating, this volume of gas, however, is not seen to be in free-fall. This post-collapse filament then fragments along its length due to the growth of a Jeans-like instability to form prestellar cores like beads on a string. We suggest, dense filaments in typical star-forming clouds classified as gravitationally super-critical under the assumption of : (i) isothermality when in fact, they are not, and (ii) extended radial profiles as against one that is pressure-truncated, thereby causing significant over-estimation of their mass line-density, are unlikely to experience

12 gravitational free-fall. The radial density and temperature profile derived for this post-collapse filament is consistent with that deduced for typical filamentary clouds mapped in recent surveys of nearby star-forming regions. This profile is also in agreement with a Plummer-like density profile. For an isothermal filament though, the density profile is much steeper, consistent with the classic density profile suggested by Ostriker (1964). On the other hand, increasing the magnitude of the confining pressure such that the initial volume of gas is rendered gravitationally sub-critical is unable to collapse radially and tends to expand laterally which could possibly explain similar gas filaments found in recent surveys of some molecular clouds. Simulations were performed using smoothed particle hydrodynamics (SPH) and convergence of results is demonstrated by repeating them at higher resolution. Unlike some of the earlier work reported in literature, here we calculate gas temperature by solving the SPH energy equation and allow it to cool according to a cooling function. Accepted by Pub. of Astronomical Society of Australia (PASA) http://arxiv.org/pdf/1501.03248

Mopra CO Observations of the Bubble HII Region RCW120 Loren Anderson1,2, Lise Deharveng3, Annie Zavagno3, Pascal Tremblin4,5, Vicki Lowe6,7, Maria Cunningham6, Paul Jones6, Aonghus Mullins8 and Matt Redman9 1 West Virginia University, PO Box 6315, Morgantown, WV USA 2 Adjunct Astronomer at the National Radio Astronomy Observatory, PO Box 2, Green Bank, WV 24944, USA 3 Aix Marseille Universite, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388, Marseille, France 4 Laboratoire AIM Paris-Saclay (CEA/Irfu - Uni. Paris Diderot - CNRS/INSU), Centre d’etudes de Saclay, 91191 Gif-Sur-Yvette, France 5 Group, University of Exeter, EX4 4QL Exeter, UK 6 School of Physics, University of New South Wales, NSW 2052, Australia 7 Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia 8 Irish Research Council, EMBARK Scholar, at NUI Galway 9 Director, Centre for Astronomy, NUI Galway E-mail contact: loren.anderson at mail.wvu.edu We use the Mopra radio telescope to test for expansion of the molecular gas associated with the bubble H II region RCW120. A ring, or bubble, morphology is common for Galactic H II regions, but the three-dimensional geometry of such objects is still unclear. Detected near- and far-side expansion of the associated molecular material would be consistent with a three-dimensional spherical object. We map the J = 1 0 transitions of 12CO, 13CO, C18O, 17 → and C O, and detect emission from all isotopologues. We do not detect the 00 1−1E masing lines of CH3OH at 108.8939GHz. The strongest CO emission is from the photodissociation region (PDR),→ and there is a deficit of emission toward the bubble interior. We find no evidence for expansion of the molecular material associated with RCW120 and therefore can make no claims about its geometry. The lack of detected expansion is roughly in agreement with models for the time-evolution of an H II region like RCW120, and is consistent with an expansion speed of <1.5 km s−1. Single-position CO spectra show signatures of expansion, which underscores the importance of mapped spectra for such work. Dust temperature enhancements outside the PDR of RCW120 coincide with a deficit of emission in CO, confirming that these temperature enhancements are due to holes in the RCW120 PDR. Hα emission shows that RCW120 is leaking 5% of the ionizing photons into the interstellar medium (ISM) through PDR holes at the locations of the temperature∼ enhancements. H-alpha emission also shows a diffuse “halo” from leaked photons not associated with discrete holes in the PDR. Overall 25 10% of all ionizing photons are leaking into the nearby ISM. ± Accepted by ApJ http://arxiv.org/pdf/1412.6470

Resolved photometry of the binary components of RW Aur S. Antipin1, A. Belinski1, A. Cherepashchuk1, D. Cherjasov1, A. Dodin1, I. Gorbunov1, S. Lamzin1,M. Kornilov1, V. Kornilov1, S. Potanin1, B. Safonov1, V. Senik1, N. Shatsky1 and O. Voziakova1 1 Sternberg Astronomical Institute of Moscow State University, Universitetskij prospekt 13, Moscow, 119992 Russia

13 E-mail contact: kolja at sai.msu.ru Resolved UBVRI photometry of RW Aur binary was performed on November 13/14, 2014 during the deep dimming of RW Aur with a newly installed 2.5 meter telescope of the Caucasus observatory of Lomonosov Moscow State University at the mount Shatzhatmaz. At that moment RW Aur A was 3m fainter than in November 1994 in all spectral bands. We explain the current RW Aur A dimming as a result of≃ eclipse of the star by dust particles with size > 1µm. We found that RW Aur B is also a : it was brighter than 20 years ago at 0.7m in each of UBVRI band (gray brightening). Accepted by IBVS http://arxiv.org/pdf/1412.7661

Formation of complex organic molecules in cold objects: the role of gas phase reactions Nadia Balucani1,2, Cecilia Ceccarelli2 and Vianney Taquet3 1 Universita‘ di Perugia, Dip. di Chimica, Biologia e Biotecnologie, I-06123 Perugia, Italy 2 Univ. Grenoble Alpes, IPAG, F-38000 Grenoble, France 3 Laboratory and The Goddard Center for , Mailstop 691, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20770, USA E-mail contact: Cecilia.Ceccarelli at obs.ujf-grenoble.fr While astrochemical models are successful in reproducing many of the observed interstellar species, they have been struggling to explain the observed abundances of complex organic molecules. Current models tend to privilege grain surface over gas phase chemistry in their formation. One key assumption of those models is that radicals trapped in the grain mantles gain mobility and react on lukewarm (¿30 K) dust grains. Thus, the recent detections of (MF) and (DME) in cold objects represent a challenge and may clarify the respective role of grain surface and gas phase chemistry. We propose here a new model to form DME and MF with gas phase reactions in cold environments, where DME is the precursor of MF via an efficient reaction overlooked by previous models. Furthermore, methoxy, a precursor of DME, is also synthetized in the gas phase from , which is desorbed by a non-thermal process from the ices. Our new model reproduces fairly well the observations towards L1544. It also explains, in a natural way, the observed correlation between DME and MF. We conclude that gas phase reactions are major actors in the formation of MF, DME and methoxy in cold gas. This challenges the exclusive role of grain-surface chemistry and favours a combined grain-gas chemistry. Accepted by MNRAS Letters http://arxiv.org/pdf/1501.03668

Type I Planet Migration in a Magnetized Disk. II. Effect of Vertical Angular Momentum Transport Alissa Bans1,2 Arieh Konigl1, and Ana Uribe1 1 Department of Astronomy and Astrophysics, University of Chicago, Chicago IL 60637, USA 2 present address: Astronomy Department, Adler Planetarium, Chicago, IL 60605, USA E-mail contact: abans at uchicago.edu We study the effects of a large-scale, ordered magnetic field in protoplanetary disks on Type I planet migration using a linear perturbation analysis in the ideal-MHD limit. We focus on wind-driving disks, in which a magnetic torque B0z∂B0φ/∂z (where B0z and B0φ are the equilibrium vertical and azimuthal field components) induces vertical angular∝ momentum transport. We derive the governing differential equation for the disk response and identify its and turning points. For a disk containing a slightly subthermal, pure-B0z field, the total 3D torque is close to its value in the 2D limit but remains lower than the hydrodynamic torque. In contrast with the 2D pure-B0φ field model considered by Terquem (2003), inward migration is not reduced in this case when the field amplitude decreases with radius. The presence of a subdominant B0φ component whose amplitude increases from zero at z = 0 has little effect on the torque when acting alone, but in conjunction with a B0z component it gives rise to a strong torque that speeds up the inward migration by a factor 200. This factor could, however, be reduced in a real disk by dissipation ≥

14 and magnetic diffusivity effects. Unlike all previously studied disk migration models, in the B0z + ∂B0φ/∂z case the dominant contributions to the torque add with the same sign from the two sides of the planet. We attribute this behavior to a new mode of interaction wherein a planet moves inward by plugging into the disk’s underlying angular momentum transport mechanism. Accepted by ApJ http://arxiv.org/pdf/1501.02707

A First Look at the X-ray Population of the Young Massive Cluster VVV CL077 Arash Bodaghee1,2, John A. Tomsick1, Francesca Fornasini1, Farid Rahoui3,4, Franz E. Bauer5,6,7 1 Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720, USA 2 Dept. of Chemistry, Physics, and Astronomy, Georgia College and State University, CBX 082, Milledgeville, GA 31061, USA 3 European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei M¨unchen, Germany 4 Dept. of Astronomy, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA 5 Instituto de Astrof´ısica, Facultad de F´ısica, Pontifica Universidad Cat´olica de Chile, 306, Santiago 22, Chile 6 Millennium Institute of Astrophysics, Vicu˜na Mackenna 4860, 7820436 Macul, Santiago, Chile 7 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA E-mail contact: arash.bodaghee at gcsu.edu Multi-wavelength analysis of the young massive cluster VVV CL077 is presented for the first time. Our Chandra survey of this region enabled the detection of three X-ray emitting stellar members of the cluster, as well as a possible diffuse X-ray component that extends a few arcseconds from the cluster core with an intrinsic flux of (9 3) 10−14 erg cm−2 s−1 in the 0.5–10 keV band. Infrared spectra we obtained for two of these X-ray point sources show± × absorption lines typical of the of massive O stars. The X-ray spectrum from the visible extent of VVV CL077 i.e., ′′ +4 22 −2 a 15 -radius around the cluster, can be modeled with an absorbed power law with nH = (6−3) 10 cm and Γ = 2 1. In addition, the X-ray core of VVV CL077 coincides with diffuse emission seen in the infrared× band and with a local± maximum in the radio continuum map. A possible association with a neighboring H II region would place VVV CL077 at a distance of around 11 kpc; on the far side of the Norma Arm. At this distance, the cluster is 0.8 pc wide 3 −3 with a mass density of (1–4) 10 M⊙ pc . × Accepted by ApJ http://arxiv.org/pdf/1501.00496

Identification of new transitional disk candidates in Lupus with Herschel I. Bustamante1,2,3, B. Mer´ın1, A.´ Ribas1,2,3, H. Bouy2, T. Prusti4, G.L. Pilbratt4, and Ph. Andr´e5 1 European Space Astronomy Centre (ESA), P.O. Box, 78, 28691 Villanueva de la Ca˜nada, Madrid, Spain 2 Centro de Astrobiolog´ıa, INTA-CSIC, P.O. Box - Apdo. de correos 78, Villanueva de la Ca˜nada Madrid 28691, Spain 3 ISDEFE - ESAC, P.O. Box, 78, 28691 Villanueva de la Ca˜nada, Madrid, Spain 4 ESA Science Support Office, ESTEC/SRE-S, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands 5 Laboratoire AIM Paris, Saclay, CEA/DSM, CNRS, Universit´eParis Diderot, IRFU, Service d’Astrophysique, Centre d’Etudes de Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette, France E-mail contact: ibustamante at cab.inta-csic.es New data from the Herschel Space Observatory are broadening our understanding of the physics and evolution of the outer regions of protoplanetary disks in star forming regions. In particular they prove to be useful to identify transitional disk candidates. The goals of this work are to complement the detections of disks and the identification of transitional disk candidates in the Lupus clouds with data from the Herschel Survey. We extracted photometry at 70, 100, 160, 250, 350 and 500 µm of all spectroscopically confirmed Class II members previously identified in the Lupus regions and analyzed their updated spectral energy distributions. We have detected 34 young disks in Lupus in at least one Herschel band, from an initial sample of 123 known members in the observed fields. Using the criteria defined in Ribas et al. (2013) we have identified five transitional disk candidates in the region. Three of them are new to the literature. Their PACS-70 µm fluxes are systematically higher than those of normal T Tauri

15 stars in the same associations, as already found in T Cha and in the transitional disks in the Chamaeleon molecular cloud. Herschel efficiently complements mid-infrared surveys for identifying transitional disk candidates and confirms that these objects seem to have substantially different outer disks than the T Tauri stars in the same molecular clouds. Accepted by A&A http://arxiv.org/pdf/1501.05204

Discovery of two embedded clusters with WISE in the high Galactic latitude cloud HRK 81.4 77.8 − D. Camargo1,2, E. Bica1, C. Bonatto1, and G. Salerno1 1 Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Gon¸calves 9500 Porto Alegre 91501-970, RS, Brazil 2 Col´egio Militar de Porto Alegre, Minist´erio da Defesa - Ex´ercito Brasileiro, Av. Jos´eBonif´acio 363 Porto Alegre 90040-130, RS, Brazil E-mail contact: denilso.camargo at ufrgs.br Molecular clouds at very high latitude (b> 60◦) away from the Galactic plane are rare and in general are expected to be non-star-forming. However, we report the discovery of two embedded clusters (Camargo 438 and Camargo 439) within the high-latitude molecular cloud HRK 81.4 77.8 using WISE. Camargo 439 with Galactic coordinates l = 81◦.11 and ◦ − b = 77.84 is an 2 Myr embedded cluster (EC) located at a distance from the of d⊙ =5.09 0.47 kpc. Adopting − ∼ ± the distance of the Sun to the Galactic centre R⊙ =7.2 kpc we derive for Camargo 439 a Galactocentric distance of ◦ RGC = 8.70 0.26 kpc and a vertical distance from the plane of 4.97 0.46 kpc. Camargo 438 at l = 79.66 and b = 78◦.86 presents± similar values. The derived parameters for these− two± ECs put HRK 81.4 77.8 in the halo at a distance− from the Galactic centre of 8.7 kpc and 5.0 kpc from the disc. Star clusters provide− the only direct means to determine the high latitude molecular∼ cloud distances.∼ The present study shows that the molecular cloud HRK 81.4 77.8 is currently forming stars, apparently an unprecedented event detected so far among high latitude clouds. We carried− out a preliminary analysis. It shows that this ECs are the most distant known embedded clusters from the plane and both cloud and clusters are probably falling ballistically from the halo onto the Galactic disc, or performing a flyby. Accepted by MNRAS http://arxiv.org/pdf/1501.03707

Gemini-IFU of HH 111 A. H. Cerqueira1, M. J. Vasconcelos1, A. C. Raga2, J. A. Feitosa1 and H. Plana1 1 Universidade Estadual de Santa Cruz, Ilh´eus, Bahia, Brazil 2 Universidad Nacional Aut´onoma de M´exico, DF, M´exico E-mail contact: hoth at uesc.br We present new optical observations of the HH 111 Herbig-Haro jet using the Gemini Multi Object Spectrograph in its Integral Field Unit mode. Eight fields of 5” 3.5” have been positioned along and across the HH 111 jet, covering the spatial region from knot E to L in HH 111× (namely, knots E, F, G, H, J, K and L). We present images and velocity channel maps for the [O I] 6300+6360, Hα, [N II] 6548+6583 and [S II] 6716+6730 lines, as well as for the [S II]6716/6730 line ratio. We find that the HH 111 jet has an inner region with lower excitation and higher , surrounded by a broader region of higher excitation and lower radial velocity. Also, we find higher electron densities at lower radial velocities. These results imply that the HH 111 jet has a fast, axial region with lower velocity shocks surrounded by a lower velocity sheath with higher velocity shocks. Accepted by The Astronomical Journal http://arxiv.org/pdf/1501.03036

16 Detection of towards the solar-type protostar NGC1333 IRAS2A Audrey Coutens1, Magnus V. Persson2, Jes K. Jørgensen1, Susanne F. Wampfler1 and Julie M. Lykke1 1 Centre for Star and Planet Formation, Niels Bohr Institute and Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark 2 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands E-mail contact: acoutens at nbi.dk Glycolaldehyde is a key molecule in the formation of biologically relevant molecules such as ribose. We report its detection with the Plateau de Bure interferometer towards the Class 0 young stellar object NGC1333 IRAS2A, which is only the second solar-type protostar for which this prebiotic molecule is detected. Local thermodynamic equilibrium analyses of glycolaldehyde, glycol (the reduced alcohol of glycolaldehyde) and methyl formate (the most abundant isomer of glycolaldehyde) were carried out. The relative abundance of to glycolaldehyde is found to be 5 - higher than in the Class 0 source IRAS 16293-2422 ( 1), but comparable to the lower limits derived in ( ∼3-6). The different ethylene glycol-to-glycolaldehyde ratios∼ in the two protostars could be related to ≥ different CH3OH:CO compositions of the icy grain mantles. In particular, a more efficient hydrogenation on the grains in NGC1333 IRAS2A would favor the formation of both methanol and ethylene glycol. In conclusion, it is possible that, like NGC1333 IRAS2A, other low-mass protostars show high ethylene glycol-to-glycolaldehyde abundance ratios. The cometary ratios could consequently be inherited from earlier stages of star formation, if the young Sun experienced conditions similar to NGC1333 IRAS2A. Accepted by A&A http://arxiv.org/pdf/1502.00896

6.7GHz Methanol Maser Associated Outflows: An evolutionary sequence H.M. de Villiers1, A. Chrysostomou1, M. A. Thompson1, J. S. Urquhart2, S. L. Breen3, M. G. Burton4, S. P. Ellingsen5, G. A. Fuller6, M. Pestalozzi7, M. A. Voronkov8 and D. Ward-Thompson9 1 Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AB, UK 2 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, D-53121 Bonn, Germany 3 CSIRO Astronomy and Space Science, Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, Australia 4 School of Physics, University of New South Wales, Sydney, NSW 2052, Australia 5 School of Physical Science, University of Tasmania, Private Bag 37, Hobart 7001, TAS, Australia 6 Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, Alan Turing Building, University of Manchester, Oxford Road, Manchester, M13 9PL, UK 7 IAPS - INAF, via del Fosso del Cavaliere 100, 00133 Roma, Italy 8 Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia 9 Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire, PR1 2HE, United Kingdom E-mail contact: lientjiedv at gmail.com We present a continuing study of a sample 44 molecular outflows, observed in 13CO lines, closely associated with 6.7GHz methanol masers, hence called Methanol Maser Associated Outflows (MMAOs). We compare MMAO properties with those of outflows from other surveys in the literature. In general, MMAOs follow similar trends, but show a deficit in number at low masses and momenta, with a corresponding higher fraction at the high end of the distributions. A similar trend is seen for the dynamical timescales of MMAOs. We argue that the lack of relatively low mass and young flows in MMAOs is due to the inherent selection-bias in the sample, i.e. its direct association with 6.7GHz methanol masers. This implies that methanol masers must switch on after the onset of outflows (hence accretion), and not before a sufficient abundance of methanol is liberated from icy dust mantles. Consequently the average dynamical age of MMAOs is older than for the general population of molecular outflows. We propose an adjusted evolutionary sequence of outflow and maser occurrence in the hot core phase, where methanol masers turn on after the onset of the outflow phase. Accepted by Monthly Notices of the Royal Astronomical Society http://arxiv.org/pdf/1501.06589

17 Non-LTE Modelling of the Structure and Spectra of the Hot Accretion Spots on the Surface of Young Stars A.V. Dodin1 1 Sternberg Astronomical Institute of Moscow State University, Universitetskij prospekt 13, Moscow, 119992 Russia E-mail contact: samsebedodin at gmail.com The paper describes the modelling of the structure and spectra of the hot accretion spots on the surface of young stars with taking into account departures from LTE for and . It has been found that the existence of the ram pressure of the in-falling gas at the outer boundary of the hot spot leads to the Stark broadening of the hydrogen line profiles up to FWHM 1000 kms−1 at the considered accretion parameters. It is shown that taking into account departures from LTE for ∼ and ions of carbon and does not lead to noticeable changes in the structure of the hot spot. Accepted by Astronomy Letters http://arxiv.org/pdf/1412.7668

An Optical Spectroscopic Survey of the Serpens Main Cluster: Evidence for Two Populations? Kristen L. Erickson1, Bruce A. Wilking1, Michael R. Meyer2, Jinyoung Serena Kim3, William Sherry4 and Matthew Freeman1 1 University of Missouri-St. Louis, USA 3 Institute for Astronomy, Swiss Federal Institute of Technology, Switzerland 4 Steward Observatory, , USA 5 National Optical Astronomy Observatories, USA E-mail contact: bwilking at umsl.edu We have completed an optical spectroscopic survey of a sample of candidate young stars in the Serpens Main star- forming region selected from deep B, V, and R band images. While infrared, X-ray, and optical surveys of the cloud have identified many young stellar objects (YSOs), these surveys have been biased toward particular stages of pre- main sequence evolution. We have obtained over 700 moderate resolution optical spectra that, when combined with published data, have led to the identification of 63 association members based on the presence of Hα in emission, lithium absorption, X-ray emission, a mid-infrared excess, and/or reflection nebulosity. Twelve YSOs are identified based on the presence of lithium absorption alone. An additional 16 objects are classified as possible association members and their pre-main sequence nature is in need of confirmation. Spectral types along with V and R band photometry were used to derive effective temperatures and bolometric for association members to compare with theoretical tracks and isochrones for pre-main sequence stars. An average age of 2 Myr is derived for this population. When compared to simulations, there is no obvious evidence for an age spread when considering the major sources of uncertainties in the derived luminosities. However when compared to the young cluster in Ophiuchus, the association members in Serpens appear to have a larger spread in luminosities and hence ages which could be intrinsic to the region or the result of a foreground population of YSOs associated with the Aquila Rift. Modeling of the spectral energy distributions from optical though mid-infrared wavelengths has revealed three new transition disk objects, making a total of six in the cluster. Echelle spectra for a subset of these sources enabled estimates of v sini for 7 association members. Analysis of -sensitive lines in the echelle and moderate resolution spectra of the association members indicate surface consistent with dwarf or sub-giant stars. Accepted by The Astronomical Journal

Complex organic molecules in organic-poor massive young stellar objects Edith C. Fayolle1,2, Karin I. Oberg¨ 2, Robin T. Garrod3, Ewine F. van Dishoeck1, and Suzanne E. Bisschop4,5 1 Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

18 3 Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853-6801, USA 4 The Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, Copenhagen K., Denmark DK-1350 5 The Centre for Star and Planet Formation, Niels Bohr Institute, Juliane Mariesvej 30, Copenhagen Ø., Denmark, DK-2100 E-mail contact: efayolle at cfa.harvard.edu Context. Massive young stellar objects (MYSOs) with hot cores are classic sources of complex organic molecules. The origins of these molecules in such sources, as well as the small- and large-scale differentiation between - and oxygen-bearing complex species, are poorly understood. Aim. We aim to use complex molecule abundances toward a chemically less explored class of MYSOs with weak hot organic emission lines to constrain the impact of hot molecular cores and initial ice conditions on the chemical composition toward MYSOs. Methods. We use the IRAM 30m and the Submillimeter Array to search for complex organic molecules over 8–16 GHz in the 1 mm atmospheric window toward three MYSOs with known ice abundances, but without luminous molecular hot cores. Results. Complex molecules are detected toward all three sources at comparable abundances with respect to CH3OH to classical hot core sources. The relative importance of CH3CHO, CH3CCH, CH3OCH3, CH3CN, and HNCO differ between the organic-poor MYSOs and hot cores, however. Furthermore, the N-bearing molecules are generally concentrated toward the source centers, while most O- and C-bearing molecules are present both in the center and in the colder envelope. Gas-phase HNCO/CH3OH ratios are tentatively correlated with the ratios of NH3 ice over CH3OH ice in the same lines of sight, which is consistent with new gas-grain model predictions. Conclusions. Hot cores are not required to form complex organic molecules, and source temperature and initial ice composition both seem to affect complex organic distributions toward MYSOs. To quantify the relative impact of temperature and initial conditions requires, however, a larger spatially resolved survey of MYSOs with ice detections. Accepted by A&A http://arxiv.org/pdf/1501.03168

First detection of CF+ towards a high-mass protostar Sarah Fechtenbaum1,2, Sylvain Bontemps1,2, Nicola Schneider1,2, Timea Csengeri3, Ana Duarte-Cabral4, Fabrice Herpin1,2 and Bertrand Lefloch5 1 Univ. Bordeaux, LAB, UMR 5804, F-33270, Floirac, France 2 CNRS, LAB, UMR 5804, F-33270, Floirac, France 3 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, 53121 Bonn, Germany 4 School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK 5 Laboratoire AIM Paris-Saclay, CEA/IRFU - CNRS/INSU - Universit´e Paris Diderot, CEA-Saclay, Gif-sur-Yvette Cedex, France E-mail contact: Sarah.Fechtenbaum at obs.u-bordeaux1.fr We report the first detection of the J = 1 - 0 (102.6 GHz) rotational lines of CF+ (fluoromethylidynium ion) towards CygX-N63, a young and massive protostar of the region. This detection occurred as part of an unbiased spectral survey of this object in the 0.8 3 mm range, performed with the IRAM 30m telescope. The data were analyzed using a local thermodynamical equilibrium− model (LTE model) and a population diagram in order to derive the column density. The line velocity (–4 km s−1) and line width (1.6 km s−1) indicate an origin from the collapsing envelope of the protostar. We obtain a CF+ column density of 4 1011cm−2. The CF+ ion is thought to be a good tracer for C+ and assuming a ratio of 10−6 for CF+/C+, we derive× a total number of C+ of 1.2 1053 within the beam. There is no evidence of carbon ionization caused by an exterior source of UV photons suggesting× that the protostar itself is the source of ionization. Ionization from the protostellar photosphere is not efficient enough. In contrast, X-ray ionization from the accretion shock(s) and UV ionization from outflow shocks could provide a large enough ionizing power to explain our CF+ detection. Surprisingly, CF+ has been detected towards a cold, massive protostar with no sign of an external photon dissociation region (PDR), which means that the only possibility is the existence of a significant inner source of C+. This is an

19 important result that opens interesting perspectives to study the early development of ionized regions and to approach the issue of the evolution of the inner regions of collapsing envelopes of massive protostars. The existence of high energy radiations early in the evolution of massive protostars also has important implications for chemical evolution of dense collapsing gas and could trigger peculiar chemistry and early formation of a hot core. Accepted by Astronomy & Astrophysics http://arxiv.org/pdf/1501.05439

The density structure and star formation rate of non-isothermal polytropic turbulence Christoph Federrath1 and Supratik Banerjee2 1 Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611, Australia 2 Institut f¨ur Geophysik und Meteorologie, Pohligstrasse 3, D-50969 Cologne, Germany E-mail contact: christoph.federrath at anu.edu.au The interstellar medium of galaxies is governed by supersonic turbulence, which likely controls the star formation rate (SFR) and the initial mass function (IMF). Interstellar turbulence is non-universal, with a wide range of Mach numbers, magnetic fields strengths, and driving mechanisms. Although some of these parameters were explored, most previous works assumed that the gas is isothermal. However, we know that cold molecular clouds form out of the warm atomic medium, with the gas passing through chemical and thermodynamic phases that are not isothermal. Here we determine the role of temperature variations by modelling non-isothermal turbulence with a polytropic equation of state (EOS), where pressure and temperature are functions of gas density, P ρΓ, T ρΓ−1. We use grid resolutions of 20483 cells and compare polytropic exponents Γ = 0.7 (soft EOS), Γ = 1 (isothermal∼ ∼ EOS), and Γ = 5/3 (stiff EOS). We find a complex network of non-isothermal filaments with more small-scale fragmentation occurring for Γ < 1, while Γ > 1 smoothes out density contrasts. The density probability distribution function (PDF) is significantly affected by temperature variations, with a power-law tail developing at low densities for Γ > 1. In contrast, the PDF becomes closer to a lognormal distribution for Γ < 1. We derive and test a new density variance – Mach number relation that takes Γ into account. This new relation∼ is relevant for theoretical models of the SFR and IMF, because it determines the dense gas mass fraction of a cloud, from which stars form. We derive the SFR as a function of Γ and find that it decreases by a factor of 5 from Γ=0.7toΓ=5/3. ∼ Accepted by MNRAS http://arxiv.org/pdf/1412.2756

Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula B. Fernandes1, J. Gregorio-Hetem1, T. Montmerle2, and G. Rojas3 1 Universidade de S˜ao Paulo, IAG, Rua do Mat˜ao 1226, 05508-900 Sao Paulo, Brazil 2 Institut d’Astrophysique de Paris, France 3 Universidade Federal de S˜ao Carlos, SP, Brazil E-mail contact: beatriz.fernandes at iag.usp.br We studied a sample of stars associated with the Sh 2-296 nebula, part of the reflection nebulae complex in the region of Canis Major (CMa R1). Our sample corresponds to optical counterparts of X-ray sources detected from observations with the XMM-Newton satellite, which revealed dozens of possible low-mass young stars not yet known in this region. A sample of 58 young star candidates were selected based on optical spectral features, mainly Hα and lithium lines, observed with multi-objects spectroscopy performed by the Gemini South telescope. Among the candidates, we find 41 confirmed T Tauri and 15 very likely young stars. Based on the Hα emission, the T Tauri stars were distinguished between classical (17%) and weak-lined (83%), but no significant difference was found in the age and mass distribution of these two classes. The characterization of the sample was complemented by near- and mid-infrared data, providing an estimate of ages and masses from the comparison with pre-main-sequence evolutionary models. While half of the young stars have an age of 1–2 Myrs or less, only a small fraction ( 25%) shows evidence of IR excess revealing the presence of circumstellar discs. This low fraction is quite rare compared∼ to most young star-forming regions, suggesting that some external

20 factor has accelerated the disc dissipation. Accepted by MNRAS http://arxiv.org/pdf/1501.03763

Optical and infrared counterparts of the X-ray sources detected in the Chandra Cygnus OB2 Legacy Survey M.G. Guarcello1,2, J.J. Drake2, N.J. Wright3,2, T. Naylor4, E. Flaccomio1, V.L. Kashyap2, D. Garc´ıa- Alvarez5,6,7 1 INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134, Palermo, Italy 2 Smithsonian Astrophysical Observatory, MS-67, 60 Garden Street, Cambridge, MA 02138, USA 3 CAR/STRI, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK 4 School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK 5 Dpto. de Astrof´ısica, Universidad de La Laguna, 38206 - La Laguna, Tenerife, Spain 6 Grantecan CALP, 38712 Bre˜na Baja, La Palma, Spain 7 Instituto de Astrof´ısica de Canarias, E-38205 La Laguna, Tenerife, Spain E-mail contact: mguarce at astropa.unipa.it The young massive OB association Cygnus OB2, in the Cygnus X complex, is the closest (1400 pc) star forming region to the Sun hosting thousands of young low mass stars and up to 1000 OB stars, among which are some of the most massive stars known in our Galaxy. This region holds great importance for several fields of modern astrophysics, such as the study of the physical properties of massive and young low-mass stars and the feedback provided by massive stars on star and planet formation process. Cygnus OB2 has been recently observed with Chandra/ACIS-I as part of the 1.08 Msec Chandra Cygnus OB2 Legacy Project. This survey detected 7924 X-ray sources in a square degree area centered on Cyg OB2. Since a proper classification and study of the observed X-ray sources also requires the analysis of their optical and infrared counterparts, we combined a large and deep set of optical and infrared catalogs available for this region with our new X-ray catalog. In this paper we describe the matching procedure and present the combined catalog containing 5703 sources. We also briefly discuss the nature of the X-ray sources with optical and infrared counterparts using their position in the color-magnitude and color-color diagrams. Accepted by ApJ http://arxiv.org/pdf/1501.03761

Structure and Stability of Filamentary Clouds Supported by Lateral Tomoyuki Hanawa1 and Kohji Tomiaska2 1 Center for Frontier Science, Chiba University, Chiba 263-8522, Japan 2 Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka 181-8588, Japan E-mail contact: hanawa at faculty.chiba-u.jp We have constructed two types of analytical models for an isothermal filamentary cloud supported mainly by magnetic tension. The first one describes an isolated cloud while the second considers filamentary clouds spaced periodically. Both the models assume that the filamentary clouds are highly flattened. The former is proved to be the asymptotic limit of the latter in which each filamentary cloud is much thinner than the distance to the neighboring filaments. We show that these models reproduce main features of the 2D equilibrium model of Tomisaka (2014) for filamentary cloud threaded by perpendicular magnetic field. It is also shown that the critical mass to flux ratio is M/Φ = (2π√G)−1, where M, Φ and G denote the cloud mass, the total magnetic flux of the cloud, and the gravitational constant, respectively. This upper bound coincides with that for an axisymmetric cloud supported by poloidal magnetic fields. We applied the variational principle for studying the Jeans instability of the first model. Our model cloud is unstable against fragmentation as well as the filamentary clouds threaded by longitudinal magnetic field. The fastest growing mode has a wavelength several times longer than the cloud diameter. The second model describes quasi-static evolution of filamentary molecular cloud by ambipolar diffusion. Accepted by The Astrophysical Journal http://arxiv.org/pdf/1501.07734

21 Testing protostellar disk formation models with ALMA observations D. Harsono1,2, E.F. van Dishoeck1,3, S. Bruderer3, Z.-Y. Li4, and J.K. Jørgensen5,6 1 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2300 RA, Leiden, the Netherlands 2 SRON Netherlands Institute for Space Research, PO Box 800, 9700 AV, Groningen, The Netherlands 3 Max-Planck-Institut f¨ur extraterretrische Physik, Giessenbachstrasse 1, 85748, Garching, Germany 4 Astronomy Department, University of Virginia, Charlottesville, VA, USA 5 Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark 6 Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark E-mail contact: harsono at strw.leidenuniv.nl Recent simulations have explored different ways to form accretion disks around low-mass stars. We aim to present observables to differentiate a rotationally supported disk from an infalling rotating envelope toward deeply embedded young stellar objects and infer their masses and sizes. Two 3D magnetohydrodynamics (MHD) formation simulations and 2D semi-analytical model are studied. The dust temperature structure is determined through continuum radiative transfer RADMC3D modelling. A simple temperature dependent CO abundance structure is adopted and synthetic spectrally resolved submm rotational molecular lines up to Ju =10 are simulated. All models predict similar compact components in continuum if observed at the spatial resolutions of 0′′. 5–1′′ (70–140 AU) typical of the observations to date. A spatial resolution of 14 AU and high dynamic range (>1000) are required to differentiate between RSD and pseudo-disk in the continuum.∼ The peak-position velocity diagrams indicate that the pseudo-disk shows a flatter velocity profile with radius than an RSD. On larger-scales, the CO isotopolog single-dish line profiles are similar and are narrower than the observed line widths of low-J lines, indicating significant turbulence in the large-scale envelopes. However a forming RSD can provide the observed line widths of high-J lines. Thus, either RSDs are common or a higher level of turbulence (b 0.8 km s−1) is required in the inner envelope compared with the outer part. Multiple spatially and spectrally resolved∼ molecular line observations are needed. The continuum data give a better estimate on disk masses whereas the disk sizes can be estimated from the spatially resolved molecular lines observations. The general observable trends are similar between the 2D semi-analytical models and 3D MHD RSD simulations. Accepted by A&A http://arxiv.org/pdf/1501.01417

Collisions of small ice particles under microgravity conditions (II): Does the chemical composition of the ice change the collisional properties? C.R. Hill1, D. Heißelmann2,3, J. Blum2, H.J. Fraser1 1 The Open University, Department of Physical Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK 2 Technische Universit¨at Braunschweig, Institut f¨ur Geophysik und extraterrestrische Physik, Mendelssohnstraße 3, 38106 Braunschweig, Germany 3 International Max-Planck Research School, Max-Planck Institute of Solar System Research, Justus-von-Liebig-Weg 3, 37077 G¨ottingen, Germany E-mail contact: catherine.hill at open.ac.uk Context: Understanding the collisional properties of ice is important for understanding both the early stages of planet formation and the evolution of planetary ring systems. Simple chemicals such as methanol and are known to be present in cold protostellar regions alongside the dominant ice; they are also likely to be incorporated into which form in protoplanetary disks, and planetary ring systems. However, the effect of the chemical composition of the ice on its collisional properties has not yet been studied. Aims: Collisions of 1.5 cm ice spheres composed of pure crystalline water ice, water with 5% methanol, and water with 5% formic acid were investigated to determine the effect of the ice composition on the collisional outcomes. Methods: The collisions were conducted in a dedicated experimental instrument, operated under microgravity condi- tions, at relative particle impact velocities between 0.01 and 0.19 m s−1, temperatures between 131 and 160 K and a pressure of around 10−5 mbar. Results: A range of coefficients of restitution were found, with no correlation between this and the chemical com- position, relative impact velocity, or temperature. Conclusions: We conclude that the chemical composition of the

22 ice (at the level of 95% water ice and 5% methanol or formic acid) does not affect the collisional properties at these temperatures and due to the inability of surface wetting to take place. At a level of 5% methanol or formic acid, the structure is likely to be dominated by crystalline water ice, leading to no change in collisional properties. The surface roughness of the particles is the dominant factor in explaining the range of coefficients of restitution. Accepted by A&A http://arxiv.org/pdf/1501.00830

ALMA Imaging of Millimeter/Submillimeter Continuum Emission in Orion KL Tomoya Hirota1,2, Mi Kyoung Kim3, Yasutaka Kurono4,5 and Mareki Honma1,2 1 National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan 2 Department of Astronomical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan 3 Korea Astronomy and Space Science Institute, Hwaam-dong 61-1, Yuseong-gu, Daejeon, 305-348, Republic of Korea 4 Chile Observatory, National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan 5 Joint ALMA Observatory, Alonso de Cordova 3107 Vitacura, Santiago 763-0355, Chile E-mail contact: tomoya.hirota at nao.ac.jp We have carried out high resolution observations with Atacama Large Millimeter/Submillimeter Array (ALMA) of continuum emission from Orion KL region. We identify 11 compact sources at ALMA band 6 (245 GHz) and band 7 (339 GHz), including Hot Core, Compact Ridge, SMA1, IRc4, IRc7, and a radio source I (Source I). Spectral energy distribution (SED) of each source is determined by using previous 3 mm continuum emission data. Physical properties such as size, mass, hydrogen number density and column density are discussed based on the dust graybody SED. Among 11 identified sources, Source I, a massive protostar candidate, is a dominant energy source in Orion KL. We extensively investigate its SED from centimeter to submillimeter wavelengths. The SED of Source I can be fitted with a single power-law index of 1.97 suggesting an optically thick emission. We employ the H− free-free emission as an opacity source of this optically thick emission. The temperature, density, and mass of the circumstellar disk associated with Source I are constrained by the SED of H− free-free emission. Still the fitting result shows a significant deviation from the observed flux densities. Combined with the thermal dust graybody SED to explain excess emission at higher frequency, a smaller power-law index of 1.60 for the H− free-free emission is obtained in the SED fitting. The power-law index smaller than 2 would suggest a compact source size or a clumpy structure unresolved with the present study. Future higher resolution observations with ALMA are essential to reveal more detailed spatial structure and physical properties of Source I. Accepted by ApJ http://arxiv.org/pdf/1502.00458

Magnetic Turbulence and Thermodynamics in the Inner Region Shigenobu Hirose1 1 Department of Mathematical Science and Advanced Technology, Japan Agency for Marine- Science and Tech- nology, Yokohama, Kanagawa 236-0001, Japan E-mail contact: hirose.shigenobu at gmail.com Using radiation magnetohydrodynamics simulations with realistic opacities and equation of state, and zero net mag- netic flux, we have explored thermodynamics in the inner part of protoplanetary discs where magnetic turbulence is expected. The thermal equilibrium curve consists of the upper, lower, and middle branches. The upper (lower) branch corresponds to hot (cool) and optically very (moderately) thick discs, respectively, while the middle branch is charac- terized by convective energy transport near the midplane. Convection is also the major energy transport process near the low surface density end of the upper branch. There, convective motion is fast with Mach numbers reaching >0.01, and enhances both magnetic turbulence and cooling, raising the ratio of vertically-integrated shear stress to vertically-∼ integrated pressure by a factor of several. This convectively enhanced ratio seems a robust feature in accretion discs having an ionization transition. We have also examined causes of the S-shaped thermal equilibrium curve, as well as the thermal stability of the equilibrium solutions. Finally, we compared our results with the disc instability models

23 used to explain FU Ori outbursts. Although the thermal equilibrium curve in our results also exhibits bistability, the surface density contrast across the bistability is an order of magnitude smaller, and the stress-to-pressure ratios in both upper and lower branches are two orders of magnitude greater, than those favored in the disc instability models. It therefore appears likely that FU Ori outbursts are not due solely to a thermal-viscous limit cycle resulting from accretion driven by local magnetic turbulence. Accepted by MNRAS http://arxiv.org/pdf/1501.06912

Star-formation rates from young-star counts and the structure of the ISM across the NGC346/N66 complex in the SMC S. Hony1, D. A. Gouliermis1,2, F. Galliano3, M. Galametz4, D. Cormier1, C.-H. R. Chen5, S. Dib6,7, A. Hughes8,9,2, R. S. Klessen1,10,11, J. Roman-Duval12, L. Smith13, J.-P. Bernard8,9, C. Bot14, L. Carlson15, K. Gordon12,16, R. Indebetouw15,17, V. Lebouteiller3, M.-Y. Lee3, S. C. Madden3, M. Meixner12,18, J. Oliveira19, M. Rubio20, M. Sauvage3 and R. Wu21 1 Universit¨at Heidelberg, Zentrum f¨ur Astronomie, Institut f¨ur Theoretische Astrophysik, Germany 2 Max Planck Institute for Astronomy, Germany 3 Laboratoire AIM, CEA/IRFU/Service d’Astrophysique, Universite Paris Diderot, France 4 European Southern Observatory, Germany 5 Max-Planck-Institut f¨ur Radioastronomie, Germany 6 Niels Bohr International Academy, Niels Bohr Institute, Denmark 7 Centre for Star and Planet Formation, University of Copenhagen, Denmark 8 CNRS, IRAP, France 9 Universite de Toulouse, UPS-OMP, IRAP, France 10 Department of Astronomy and Astrophysics, University of California, USA 11 Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, USA 12 Space Telescope Science Institute, USA 13 Space Telescope Science Institute and European Space Agency 14 Observatoire Astronomique de Strasbourg, Universite de Strasbourg, CNRS, UMR 7550, France 15 Department of Astronomy, University of Virginia, USA 16 Sterrenkundig Observatorium, Universiteit Gent, Belgium 17 National Radio Astronomical Observatory, USA 18 The Johns Hopkins University, Department of Physics and Astronomy, USA 19 School of Physical & Geographical Sciences, Lennard-Jones Laboratories, Keele University, UK 20 Departamento de Astronomia, Universidad de Chile 21 Department of Astronomy, Graduate School of Science, The University of Tokyo, Japan E-mail contact: sacha.hony at free.fr The rate at which interstellar gas is converted into stars, and its dependence on environment, is one of the pillars on which our understanding of the visible is build. We present a comparison of the surface density of young stars 2 (Σ∗) and dust surface density (Σd) across NGC346 (N66) in 115 independent pixels of 6 6pc . We find a correlation × between Σ∗ and Σd with a considerable scatter. A power law fit to the data yields a steep relation with an exponent of 2.6 0.2. We convert Σd to gas surface density (Σg) and Σ∗ to star formation rate (SFR) surface densities (ΣSFR), using± simple assumptions for the gas-to-dust mass ratio and the duration of star formation. The derived total SFR −3 −1 (4 1 10 M⊙yr ) is consistent with SFR estimated from the Hα emission integrated over the Hα nebula. On small ± · scales the ΣSFR derived using Hα systematically underestimates the count-based ΣSFR, by up to a factor of 10. This is due to ionizing photons escaping the area, where the stars are counted. We find that individual 36 pc2 pixels fall systematically above integrated disc-galaxies in the Schmidt-Kennicutt diagram by on average a factor of 7. The NGC346 average SFR over a larger area (90 pc radius) lies closer to the relation but remains high by a factor∼ of 3. The fraction of the total mass (gas plus young stars) locked in young stars is systematically high ( 10 per cent) within∼ the central 15 pc and systematically lower outside (2 per cent), which we interpret as variations∼ in star formation efficiency. The inner 15 pc is dominated by young stars belonging to a centrally condensed cluster, while the outer parts are dominated by a dispersed population. Therefore, the observed trend could reflect a change of star formation

24 efficiency between clustered and non-clustered star-formation. Accepted by MNRAS http://arxiv.org/pdf/1501.03634

High resolution observations of the outer disk around T Cha: the view from ALMA N. Hu´elamo1, I. de Gregorio-Monsalvo2,3, E. Macias4, C. Pinte5,6, M. Ireland7, P. Tuthill8, and S. Lacour9 1 Centro de Astrobiolog´ıa(INTA-CSIC); ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Ca˜nada, Spain 2 Joint ALMA Observatory (JAO), Alonso de C´ordova 3107, Vitacura, Santiago de Chile 3 European Southern Observatory, Garching bei M¨unchen, D-85748 Germany 4 Instituto de Astrof´ısica de Andaluc´ıa, CSIC, Glorieta de la Astronom´ıas/n, E-18008 Granada, Spain 5 UMI-FCA, CNRS/INSU France (UMI 3386), and Dpto. de Astronom´ıa, Universidad de Chile, Casilla 36-D Santiago, Chile 6 Univ. Grenoble Alpes, IPAG, 38000 Grenoble, France; CNRS, IPAG, 38000 Grenoble, France 7 Research School of Astronomy and Astrophysics, Australian National University, Canberra ACT 2611, Australia 8 Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia 9 LESIA, CNRSUMR-8109, Observatoire de Paris, UPMC, Universit´e Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France E-mail contact: nhuelamo at cab.inta-csic.es T Cha is a young star surrounded by a transitional disk with signatures of planet formation. We have obtained high- resolution and high-sensitivity ALMA observations of T Cha in the CO (3–2), 13CO (3–2), and CS (7–6) emission lines to reveal the spatial distribution of the gaseous disk around the star. In order to study the dust within the disk we have also obtained continuum images at 850 µm from the line-free channels. We have spatially resolved the outer disk around T Cha. Using the CO (3–2) emission we derive a radius of 230 AU. We also report the detection of the 13CO (3–2) and the CS (7–8) molecular emissions, which show smaller∼ radii than the CO (3–2) detection. The continuum observations at 850 µm allow the spatial resolution of the dusty disk, which shows two emission bumps separated by 40AU, consistent with the presence of a dust gap in the inner regions of the disk, and an outer radius of 80AU. Therefore,∼ T Cha is surrounded by a compact dusty disk and a larger and more diffuse gaseous disk, as previously∼ observed in other young stars. The continuum intensity profiles are different at both sides of the disk suggesting possible dust asymmetries. We derive an inclination of i = 67◦ 5◦, and a position angle of P A = 113◦ 6◦, for both the gas and dust disks. The comparison of the ALMA data with± radiative transfer models shows that± the gas and dust components can only be simultaneously reproduced when we include a tapered edge prescription for the surface density profile. The best model suggests that most of the disk mass is placed within a radius of R< 50 AU. Finally, we derive a dynamical mass for the central object of M =1.5 0.2 M⊙, comparable to the one estimated with evolutionary models for an age of 10 Myr. ± ∼ Accepted by A&A Letters http://arxiv.org/pdf/1501.06483

On the Likelihood of Planet Formation in Close Binaries Hannah Jang-Condell1 1 University of Wyoming, Dept. of Physics & Astronomy 1000 E. University, Dept 3905, Laramie, WY 82071, USA E-mail contact: hjangcon at uwyo.edu To date, several have been discovered orbiting stars with close binary companions (a < 30 AU). The fact that planets can form in these dynamically challenging environments implies that planet formation∼ must be a robust process. The initial protoplanetary disks in these systems from which planets must form should be tidally truncated to radii of a few AU, which indicates that the efficiency of planet formation must be high. Here, we examine the truncation of circumstellar protoplanetary disks in close binary systems, studying how the likelihood of planet formation is affected over a range of disk parameters. If the semimajor axis of the binary is too small or its eccentricity is too high, the disk will have too little mass for planet formation to occur. However, we find that the stars in the

25 binary systems known to have planets should have once hosted circumstellar disks that were capable of supporting planet formation despite their truncation. We present a way to characterize the feasibility of planet formation based on binary orbital parameters such as , companion mass, eccentricity and semi-major axis. Using this measure, we can quantify the robustness of planet formation in close binaries and better understand the overall efficiency of planet formation in general. Accepted by ApJ http://arxiv.org/pdf/1501.00617

“Dust, Ice, and Gas In Time” (DIGIT) Herschel Observations of GSS30-IRS1 in Ophi- uchus Hyerin Je1, Jeong-Eun Lee1,2, Seokho Lee1, Joel D. Green2, and Neal J. Evans II2 1 School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701, Republic of Korea 2 Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205, USA E-mail contact: hyerinje at khu.ac.kr As a part of the “Dust, Ice, and Gas In Time” (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 µm to 200 µm, including CO, H2O, OH, and two atomic [O I] lines at 63 and 145 µm. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 µm. All lines, except [O I] and [C II], are detected only at the central spaxel of 9′′. 4 9′′. 4. The [O I] emissions are extended along a NE-SW orientation, and the [C II] line is detected over all spaxels,× indicative of external PDR. The total [C II] intensity around GSS30 reveals that the far- radiation −3 −2 −1 field is in the range of 3 to 20 G0, where G0 is in units of the Habing Field, 1.6 10 erg cm s . This enhanced external radiation field heats the envelope of GSS30-IRS1, causing the continuum× emission to be extended, unlike the molecular emission. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 10 L⊙, and the region is externally heated by a radiation field enhanced by a factor of 130 compared to the standard local interstellar radiation field. Accepted by ApJS http://arxiv.org/pdf/1501.05048

MALT-45: A 7 mm survey of the southern Galaxy - I. Techniques and spectral line data Christopher H. Jordan1,2, Andrew J. Walsh3, Vicki Lowe2,4, Maxim A. Voronkov2, Simon P. Ellingsen1, Shari L. Breen2, Cormac R. Purcell5, Peter J. Barnes6, Michael G. Burton4, Maria R. Cunningham4, Tracey Hill7, James M. Jackson8, Steven N. Longmore9, Nicolas Peretto10 and James S. Urquhart11,2 1School of Physical Sciences, Private Bag 37, University of Tasmania, Hobart, Tasmania 7001, Australia 2CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia 3International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6845, Australia 4School of Physics, University of New South Wales, Sydney, NSW 2052, Australia 5School of Physics, University of Sydney, Sydney, NSW 2006, Australia 6Astronomy Department, University of Florida, Gainesville, FL 32611, USA 7Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile 8Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA 9Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, Liverpool L3 5RF, UK 10School of Physics & Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK 11Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, Bonn, Germany E-mail contact: christopher.jordan at utas.edu.au We present the first results from the MALT-45 (Millimetre Astronomer’s Legacy Team - 45 GHz) Galactic Plane survey. We have observed 5 square-degrees (l = 330 335, b = 0.5) for spectral lines in the 7mm band (42–44 and − ± + 48–49 GHz), including CS(1–0), class I CH3OHmasers in the 7(0,7)–6(1,6) A transition and SiO(1–0) v = 0, 1, 2, 3.

26 MALT-45 is the first unbiased, large-scale, sensitive spectral line survey in this frequency range. In this paper, we present data from the survey as well as a few intriguing results; rigorous analyses of these science cases are reserved for future publications. Across the survey region, we detected 77 class I CH3OHmasers, of which 58 are new detections, along with many sites of thermal and maser SiOemission and thermal CS. We found that 35 class I CH3OHmasers were associated with the published locations of class II CH3OH, H2Oand OHmasers but 42 have no known masers within 60 arcsec. We compared the MALT-45 CSwith NH3(1,1) to reveal regions of CSdepletion and high opacity, as well as evolved star-forming regions with a high ratio of CSto NH3. All SiOmasers are new detections, and appear to be associated with evolved stars from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Generally, within SiOregions of multiple vibrational modes, the intensity decreases as v =1, 2, 3, but there are a few exceptions where v = 2 is stronger than v = 1. Accepted by MNRAS http://arxiv.org/pdf/1501.06650

Galactic cold cores V. Dust opacity M. Juvela1, I. Ristorcelli2,3, D.J. Marshall4, J. Montillaud1,5, V.-M. Pelkonen1,6, N. Ysard7, P. McGehee8, R. Paladini8, L. Pagani9, J. Malinen1, A. Rivera-Ingraham2, C. Lefevre9, L.V. Toth10, L.A. Montier2,3, J.-P. Bernard2,3 and P. Martin11 1 Department of Physics, P.O.Box 64, FI-00014, University of Helsinki, Finland 2 Universit´ede Toulouse, UPS-OMP, IRAP, F-31028 Toulouse cedex 4, France 3 CNRS, IRAP, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France 4 Laboratoire AIM, IRFU/Service dAstrophysique - CEA/DSM - CNRS - Universit´eParis Diderot, Bt. 709, CEA- Saclay, F-91191, Gif-sur-Yvette Cedex, France 5 Institut UTINAM, CNRS UMR 6213, OSU THETA, Universit´ede Franche-Comt´e, 41 bis avenue de l’Observatoire, 25000 Besan¸con, France 6 Finnish Centre for Astronomy with ESO (FINCA), University of Turku, V¨ais¨al¨antie 20, FI-21500 Piikki¨o, Finland 7 IAS, Universit´eParis-Sud, 91405 Orsay cedex, France 8 IPAC, Caltech, Pasadena, USA 9 LERMA, CNRS UMR8112, Observatoire de Paris, 61 avenue de l’observatoire 75014 Paris, France 10 Lor´and E¨otv¨os University, Department of Astronomy, P´azm´any P.s. 1/a, H-1117 Budapest, Hungary (OTKA K62304) 11 CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada E-mail contact: mika.juvela at helsinki.fi The project Galactic Cold Cores has carried out Herschel photometric observations of interstellar clouds where the Planck satellite survey has located cold and compact clumps. The sources represent different stages of cloud evolution from starless clumps to protostellar cores and are located in different Galactic environments. We examine this sample of 116 Herschel fields to estimate the submillimetre dust opacity and to search for variations that might be attributed to the evolutionary stage of the sources or to environmental factors, including the location within the Galaxy. The submillimetre dust opacity was derived from Herschel data, and near-infrared observations of the reddening of background stars are converted into near-infrared optical depth. We investigated the systematic errors affecting these parameters and used modelling to correct for the expected biases. The ratio of250 µm and J band opacities is correlated with the Galactic location and the star formation activity. We searched for local variations in the ratio τ(250µm)/τ(J) using the correlation plots and opacity ratio maps. We find a median ratio of τ(250µm)/τ(J) = (1.6 0.2) 10−3, which is more than three times the mean value reported for the diffuse medium. Assuming an opacity± spectral× index β = 1.8 instead of β =2.0, the value would be lower by 30%. No significant systematic variation is detected with Galactocentric distance or with Galactic height. Examination∼ of the τ(250µm)/τ(J) maps reveals six fields with clear indications of a local increase of submillimetre opacity of up to τ(250µm)/τ(J) 4 10−3 towards the densest clumps. These are all nearby fields with spatially resolved clumps of high column density.∼ × We interpret the increase in the far-infrared opacity as a sign of grain growth in the densest and coldest regions of interstellar clouds. Accepted by A&A http://arxiv.org/pdf/1501.07092

27 The Feeding Zones of Terrestrial Planets and Insights into Formation Nathan A. Kaib1,3 and Nicolas B. Cowan2,3 1 Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015, USA 2 Department of Physics & Astronomy, Amherst College, AC#2244, Amherst, MA 01002, USA 3 Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, Illinois 60208, USA E-mail contact: ncowan at amherst.edu We present an extensive suite of formation simulations that allows quantitative analysis of the stochastic late stages of planet formation. We quantify the feeding zone width, ∆a, as the mass-weighted standard deviation of the initial semi-major axes of the planetary embryos and that make up the final planet. The size of a planet’s feeding zone in our simulations does not correlate with its final mass or semi-major axis, suggesting there is no systematic trend between a planet’s mass and its volatile inventory. Instead, we find that the feeding zone of any planet more massive than 0.1 M⊕ is roughly proportional to the radial extent of the initial disk from which it formed: ∆a 0.25(amax amin), where amin and amax are the inner and outer edge of the initial disk. These wide∼ stochastic feeding− zones have significant consequences for the origin of the Moon, since the canonical scenario predicts the Moon should be primarily composed of material from Earth’s last major impactor (), yet its isotopic composition is indistinguishable from Earth. In particular, we find that the feeding zones of Theia analogs are significantly more stochastic than the planetary analogs. Depending on our assumed initial distribution of oxygen within the planetesimal disk, we find a 5% or less probability that the Earth and Theia will form with an isotopic difference equal to or smaller than the Earth∼ and Moon’s. In fact we predict that every planetary mass body should be expected to have a unique isotopic signature. In addition, we find paucities of massive Theia analogs and high velocity moon-forming collisions, two recently proposed explanations for the Moon’s isotopic composition. Our work suggests that there is still no scenario for the Moon’s origin that explains its isotopic composition with a high probability event. Accepted by Icarus http://arxiv.org/pdf/1501.03816

Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by ? Matthew A. Kenworthy1 and Eric E. Mamajek2 1 Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands 2 Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, USA E-mail contact: kenworthy at strw.leidenuniv.nl The light curve of 1SWASP J140747.93-394542.6, a 16 Myr old star in the Sco-Cen OB association, underwent a complex series of deep eclipses that lasted 56 days,∼ centered on April 2007. This light curve is interpreted as the transit of a giant that is filling up a fraction of the of an unseen secondary companion, J1407b. We fit the light curve with a model of an azimuthally symmetric ring system, including spatial scales down to the temporal limit set by the star’s diameter and relative velocity. The best ring model has 37 rings and extends out to a radius of 0.6 AU (90 million km), and the rings have an estimated total mass on the order of 100MMoon. The ring system has one clearly defined gap at 0.4 AU (61 million km), which we hypothesize is being cleared out by a < 0.8M⊕ exosatellite orbiting around J1407b. This eclipse and model implies that we are seeing a undergoing a dynamic transition to an exosatellite-sculpted ring structure and is one of the first seen outside our Solar system. Accepted by Astrophysical Journal http://arxiv.org/pdf/1501.05652

28 The Role of Turbulence and Magnetic Fields in Simulated Filamentary Structure Helen Kirk1,2,3, Mikhail Klassen2, Ralph Pudritz2,3 and Samantha Pillsworth4,2 1 Herzberg Astrophysics, National Research Council of Canada 2 Origins Institute, McMaster University, Canada 3 Department of Physics and Astronomy, McMaster University, Canada 4 Department of Astronomy and Physics, Saint Mary’s University, Canada E-mail contact: helen. at nrc-cnrc.gc.ca We use numerical simulations of turbulent cluster-forming regions to study the nature of dense filamentary structures in star formation. Using four hydrodynamic and magnetohydrodynamic simulations chosen to match observations, we identify filaments in the resulting column density maps and analyze their properties. We calculate the radial column density profiles of the filaments every 0.05 Myr and fit the profiles with the modified isothermal and pressure confined isothermal cylinder models, finding reasonable fits for either model. The filaments formed in the simulations have similar radial column density profiles to those observed. Magnetic fields provide additionalpressure support to the filaments, making ‘puffier’ filaments less prone to fragmentation than in the pure hydrodynamic case, which continue to condense at a slower rate. In the higher density simulations, the filaments grow faster through the increased importance of gravity. Not all of the filaments identified in the simulations will evolve to form stars: some expand and disperse. Given these different filament evolutionary paths, the trends in bulk filament width as a function of time, magnetic field strength, or density, are weak, and all cases are reasonably consistent with the finding of a constant filament width in different star-forming regions. In the simulations, the mean FWHM lies between 0.06 and 0.26 pc for all times and initial conditions, with most lying between 0.1 to 0.15 pc; the range in FWHMs are, however, larger than seen in typical Herschel analyses. Finally, the filaments display a wealth of substructure similar to the recent discovery of filament bundles in Taurus. Accepted by ApJ http://arxiv.org/pdf/1501.05999

A General Hybrid Radiation Transport Scheme for Star Formation Simulations on an Adaptive Grid Mikhail Klassen1, Rolf Kuiper2, Ralph Pudritz1,3, Thomas Peters4, Robi Banerjee5 and Lars Buntemeyer5 1 Department of Physics and Astronomy, McMaster University 1280 Main Street W, Hamilton, ON L8S 4M1, Canada 2 Max Planck Institute for Astronomy Knigstuhl 17, D-69117 Heidelberg, Germany 3 Origins Institute, McMaster University, 1280 Main Street W, Hamilton, ON L8S 4M1, Canada 4 Institut f¨ur Computergest¨atzte Wissenschaften, Universit¨at Z¨urich Winterthurerstrasse 190, CH-8057 Z¨urich, Switzer- land 5 Hamburger Sternwarte, Universitt Hamburg Gojenbergsweg 112, D-21029 Hamburg, Germany E-mail contact: klassm at mcmaster.ca Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodyanmics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calculating gas and dust temperatures in the presence of multiple stellar sources. Our method enables radiation-hydrodynamic studies of young stellar objects, protostellar disks, and clustered star formation in magnetized, filamentary environments. Accepted by The Astrophysical Journal http://arxiv.org/pdf/1410.4259

29 The progenitor of the FUor-type young eruptive star 2MASS J06593158 0405277 − A.´ K´osp´al1, P. Abrah´am´ 1, A. Mo´or1, M. Haas2, R. Chini2,3 and M. Hackstein2 1 Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Bu- dapest, Hungary 2 Astronomisches Institut, Ruhr-Universit¨at Bochum, Germany 3 Instituto de Astronom´ıa, Universidad Cat´olica del Norte, Antofagasta, Chile E-mail contact: kospal at konkoly.hu Only a dozen confirmed FU Orionis-type young outbursting stars (FUors) are known today; this explains the interest in the recent FUor eruption of 2MASS J06593158 0405277. Its outburst and expected decline will be subject to numerous studies in the future. Almost equally important− for the understanding of the eruption mechanism, however, is the physical characterization of the FUor’s precursor. Here we analyze unpublished archival data and summarize – and partly revise – all relevant photometry from optical to submillimeter wavelengths. Our analysis implies that the FUor is possibly associated with eight candidates and a strong Class0 source. Adopting a distance of 450 pc for the FUor, we derive a quiescent bolometric luminosity and temperature of Lbol = 4.8 L⊙ and Tbol = 1190K , typical for young ClassII sources. The central star has a temperature of Teff = 4000K, a mass of 0.75M⊙, 5 and an age of about 6 10 yr. The SED implies a circumstellar mass of 0.01 – 0.06 M⊙, and the system is surrounded by a faint infrared nebulosity.× Our results provide an almost complete picture of a FUor progenitor, supporting the interpretation of future post-outburst studies. Accepted for publication in the ApJ Letters http://arxiv.org/pdf/1501.07735

The Spatial Structure of Young Stellar Clusters. II. Total Young Stellar Populations Michael A. Kuhn1,2,3, Konstantin V. Getman1 and Eric D. Feigelson1 1 Department of Astronomy & Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA 2 Instituto de Fisica y Astronom´ıa, Universidad de Valpara´ıso, Gran Breta˜na 1111, Playa Ancha, Valpara´ıso, Chile 3 Millennium Institute of Astrophysics E-mail contact: michael.kuhn at uv.cl We investigate the intrinsic stellar populations (estimated total numbers of OB and pre–main-sequence stars down to 0.1 M⊙) that are present in 17 massive star-forming regions (MSFRs) surveyed by the MYStIX project. The study is based on the catalog of >31,000 MYStIX Probable Complex Members with both disk-bearing and disk-free populations, compensating for extinction, nebulosity, and crowding effects. Correction for observational sensitivities is made using the X-ray Luminosity Function (XLF) and the near-infrared Initial Mass Function (IMF)—a correction that is often not made by infrared surveys of young stars. The resulting maps of the projected structure of the young stellar populations, in units of intrinsic stellar surface density, allow direct comparison between different regions. Several regions have multiple dense clumps, similar in size and density to the Cluster. The highest projected density of 34,000 stars pc−2 is found in the core of the RCW 38 cluster. Histograms of surface density show different ranges∼ of values in different regions, supporting the conclusion of Bressert et al. (2010, B10) that no universal surface-density threshold can distinguish between clustered and distributed star-formation. However, a large component of the young stellar population of MSFRs resides in dense environments of 200–10,000 stars pc−2 (including within the nearby Orion molecular clouds), and we find that there is no evidence for the B10 conclusion that such dense regions form an extreme “tail” of the distribution. Tables of intrinsic populations for these regions are used in our companion study of young cluster properties and evolution. Accepted by ApJ http://arxiv.org/pdf/1501.05300 (Machine-readable tables and ’Data Behind the Figure’: http://astro.psu. edu/mystix/)

Gaia-ESO Survey: The analysis of pre-main sequence stellar spectra A.C. Lanzafame1,2, A. Frasca2, F. Damiani3, E. Franciosini4, M. Cottaar5, S.G. Sousa6,7, H.M. Tabernero8,

30 A. Klutsch2, L. Spina4, K. Biazzo2, L. Prisinzano3, G.G. Sacco4, S. Randich4, E. Brugaletta1, E. Del- gado Mena6, V. Adibekyan6, D. Montes8, R. Bonito9,3, J.F. Gameiro6, J.M. Alcal´a10, J.I. Gonz´alez Hern´andez11,25, R. Jeffries12, S. Messina2, M. Meyer5, G. Gilmore13, M. Asplund14, J. Binney15, P. Bonifacio16, J.E. Drew17, S. Feltzing18, A.M.N. Ferguson19, G. Micela3, I. Negueruela20, T. Prusti21, H-W. Rix22, A. Vallenari23, E.J. Alfaro24, C. Allende Prieto11,25, C. Babusiaux16, T. Bensby18,R. Blomme26, A. Bragaglia27, E. Flaccomio3, P. Francois16, N. Hambly19, M. Irwin13, S.E. Koposov13,28, A.J. Korn29, R. Smiljanic31, S. Van Eck32, N. Walton13, A. Bayo24,34, M. Bergemann13, G. Carraro35, M.T. Costado24, B. Edvardsson29, U. Heiter29, V. Hill30, A. Hourihane13, R.J. Jackson12, P. Jofr´e13, C. Lardo27, J. Lewis13, K. Lind13, L. Magrini4, G. Marconi35, C. Martayan35, T. Masseron13, L. Monaco35, L. Morbidelli4, L. Sbordone33, C.C. Worley13, and S. Zaggia23 1 Universit`adi Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, I-95123 Catania, Italy 2 INAF - Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, Italy 3 INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134, Palermo, Italy 4 INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Florence, Italy 5 Institute for Astronomy, ETH Zurich, Wolfgang-PauliStrasse 27, 8093, Zurich, Switzerland 6 Centro de Astrofsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal Departamento de F´ısica eAstronomia, Faculdade de Ciˆencias, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal 7 Departamento de F´ısica e Astronomia, Faculdade de Ciˆencias, Universidade do Porto, Rua do Campo Alegre, 4169- 007 Porto, Portuga 8 Universidad Complutense de Madrid, Departamento de Astrof´ısica, E-28040 Madrid, Spain 9 Universit`adi Palermo, Dipartimento di Fisica e Chimica, Viale delle Scienze, Ed. 17, I-90128 Palermo, Italy 10 INAF - Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131, Napoli, Italy 11 Instituto de Astrof´ısica de Canarias, E-38205 La Laguna, Tenerife, Spain 12 Astrophysics Group, Research Institute for the Environment, Physical Sciences and Applied Mathematics, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom 13 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, United Kingdom 14 Research School of Astronomy & Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611, Australia 15 Rudolf Peierls Centre for Theoretical Physics, Keble Road, Oxford, OX1 3NP, United Kingdom 16 GEPI, Observatoire de Paris, CNRS, Universit´eParis Diderot, 5 Place Jules Janssen, 92190 Meudon, France 17 Centre for Astrophysics Research, STRI, University of Hertfordshire, College Lane Campus, Hatfield AL10 9AB, United Kingdom 18 Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund, Sweden 19 Institute of Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, United Kingdom 20 Departamento de F´ısica, Ingenier´ıade Sistemas y Teor´ıade la Se˜nal, Universidad de Alicante, Apdo. 99, 03080, Alicante, Spain 21 ESA, ESTEC, Keplerlaan 1, Po Box 299 2200 AG Noordwijk, The Netherlands 22 Max-Planck Institut f¨ur Astronomie, K¨onigstuhl 17, 69117 Heidelberg, Germany 23 INAF - Padova Observatory, Vicolo dell’Osservatorio 5, 35122 Padova, Italy 24 Instituto de Astrof´ısica de Andaluc´ıa-CSIC, Apdo. 3004, 18080, Granada, Spain 25 Universidad de La Laguna, Dept. Astrofsica, E-38206 La Laguna, Tenerife, Spain 26 Royal Observatory of Belgium, Ringlaan 3, 1180, Brussels, Belgium 27 INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna, Italy 28 Moscow MV Lomonosov State University, Sternberg Astronomical Institute, Moscow 119992, Russia 29 Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden 30 Laboratoire Lagrange (UMR7293), Universit´ede Nice Sophia Antipolis, CNRS,Observatoire de la Cˆote d’Azur, CS 34229,F-06304 Nice cedex 4, France 31 Department for Astrophysics, Astronomical Center, ul. Rabiaska 8, 87-100 Toru´n, Poland 32 Institut d’Astronomie et d’Astrophysique, Universit´elibre de Brussels, Boulevard du Triomphe, 1050 Brussels, Belgium 33 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei M¨unchen, Germany 34 Instituto de F´ısica y Astronomi´ıa, Universidad de Valparai´ıso, Chile 35 European Southern Observatory, Alonso de Cordova 3107 Vitacura, Santiago de Chile, Chile

31 E-mail contact: Alessandro.Lanzafame at oact.inaf.it This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategies are implemented to deal with fast rotation, accretion signatures, chromospheric activity, and veiling. The analysis carried out on spectra acquired in young clusters’ fields during the first 18 months of observations, up to June 2013, is presented in preparation of the first release of advanced data products. Stellar parameters obtained with the higher resolution and larger wavelength coverage from UVES are reproduced with comparable accuracy and precision using the smaller wavelength range and lower resolution of the GIRAFFE setup adopted for young stars, which allows us to provide with confidence stellar parameters for the much larger GIRAFFE sample. Precisions are estimated to be 120 K r.m.s. in Teff , 0.3 dex r.m.s. in log g, and 0.15 dex r.m.s. in [Fe/H], for both the UVES and GIRAFFE setups.≈ ≈ ≈ Accepted by A&A http://arxiv.org/pdf/1501.04450

Sulfur-Bearing Molecules In Massive Star-Forming Regions: Observations Of OCS, CS, H2S and SO Juan Li1, Junzhi Wang1, Qingfeng Zhu2, Jiangshui Zhang3, Di Li4,5 1 Shanghai Astronomical observatory, 80 Nandan RD, Shanghai 20030, China 2 Astronomy Department, University of Science and Technology, Chinese Academy of Sciences, Hefei 210008, China 3 Center for astrophysics, Guangzhou university, Guangzhou 510006, China 4 National Astronomical Observatories, Chinese Academy of Sciences A20 Datun Road, Chaoyang District, Beijing 100012, China 5 Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing, 210008, China E-mail contact: lijuan at shao.ac.cn We studied sulfur chemistry of massive star-forming regions through single-dish submillimeter spectroscopy. OCS, 13 13 O CS, CS, H2S and SO transitions were observed toward a sample of massive star-forming regions with embedded UCH II or CH II regions. These sources could be divided into H II-hot core and H II-only sources based on their CH3CN emission. Our results show that the OCS line of thirteen sources is optically thick, with optical depth ranging from 5 to 16. Column densities of these molecules were computed under LTE conditions. CS column densities were 13 also derived using its optically thin isotopologue CS. H2S is likely to be the most abundant gas-phase sulfuretted molecules in hot assive cores. Both the column density and abundance of sulfur-bearing molecules decrease significantly from H II-hot core to H II-only sources. Ages derived from hot core models appear to be consistent with star-formation theories, suggesting that abundance ratios of [CS]/[SO], [SO]/[OCS] and [OCS]/[CS] could be used as chemical clocks in massive star-forming regions. Accepted by ApJ http://arxiv.org/pdf/1501.06018

Search for in high mass hot cores N.F.W. Ligterink1,2, E.D. Tenenbaum1and E.F. van Dishoeck1,3 1 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands 2 Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands 3 Max-Planck Institut f¨ur Extraterrestrische Physik (MPE), Giessenbackstr. 1, 85748 Garching, Germany E-mail contact: ligterink at strw.leidenuniv.nl

32 We aim to detect methylamine, CH3NH2, in a variety of hot cores and use it as a test for the importance of photon- induced chemistry in ice mantles and mobility of radicals. Specifically, CH3NH2 cannot be formed from addition to CO whereas other NH2-containing molecules such as , NH2CHO, can. Submillimeter spectra of several massive hot core regions were taken with the James Clerk Maxwell Telescope. Abundances are determined with the rotational diagram method where possible. Methylamine is not detected, giving upper limit column densities between 1.9–6.4 1016 cm−2 for source sizes corresponding to the 100 K envelope radius. Combined with previously obtained × JCMT data analyzed in the same way, abundance ratios of CH3NH2, NH2CHO and CH3CN with respect to each other and to CH3OH are determined. These ratios are compared with Sagittarius B2 observations, where all species are detected, and to hot core models. The observed ratios suggest that both methylamine and formamide are overproduced by up to an order of magnitude in hot core models. is however underproduced. The proposed chemical schemes leading to these molecules are discussed and reactions that need further laboratory studies are identified. The upper limits obtained in this paper can be used to guide future observations, especially with ALMA. Accepted by A&A http://arxiv.org/pdf/1501.01820

A long-lasting quiescence phase of the eruptive variable V1118 Ori D. Lorenzetti1, S. Antoniucci1, T. Giannini1, A. Harutyunyan2, A.A. Arkharov3, V.M. Larionov3,4,5, F. Cusano6, A. Di Paola1, G.Li Causi1, B. Nisini1, R. Speziali1 and F. Vitali1 1 INAF - Osservatorio Astronomico di Roma, via Frascati 33, Monte Porzio (Italy) 2 Fundacion INAF, Telescopio Nazionale Galileo, 38700 Santa Cruz de la Palma, Tenerife (Spain) 3 Central Astronomical Observatory of Pulkovo, Pulkovskoe shosse 65, 196140 St.Petersburg (Russia) 4 Astronomical Institute of St.Petersburg University (Russia) 5 Isaac Newton Institute of Chile, St.Petersburg branch 6 INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna (Italy) E-mail contact: dario.lorenzetti at oa-roma.inaf.it V1118 Ori is an eruptive variable belonging to the EXor class of Pre-Main Sequence stars whose episodic outbursts are attributed to disk accretion events. Since 2006, V1118 Ori is in the longest quiescence stage ever observed between two subsequent outbursts of its recent history. We present near-infrared photometry of V1118 Ori carried out during the last eight years, along with a complete spectroscopic coverage from 0.35 to 2.5 µm. A longterm sampling of V1118 Ori in quiescence has never been done, hence we can benefit from the current circumstance to determine the lowest values (i.e. the zeroes) of the parameters to be used as a reference for evaluating the physical changes typical of more −9 −1 active phases. A quiescence mass accretion rate between 1–3 10 M⊙ yr can be derived and the difference with previous determinations is discussed. From line emission and× IR colors analysis a visual extinction of 1-2 mag is consistently derived, confirming that V1118 Ori (at least in quiescence) is a low-extinction T Tauri star with a bolometric luminosity of about 2.1 L⊙. An anti-correlation exists between the equivalent width of the emission lines and the underlying continuum. We searched the literature for evaluating whether or not such a behaviour is a common feature of the whole class. The anti-correlation is clearly recognizable for all the available EXors in the optical range (Hβ and Hα lines), while it is not as much evident in the infrared (Paβ and Brγ lines). The observed anti-correlation supports the accretion-driven mechanism as the most likely to account for continuum variations. Accepted by ApJ http://arxiv.org/pdf/1501.05287

Resolved Millimeter Emission from the HD 15115 Meredith A. MacGregor1, David J. Wilner1, Sean M. Andrews1 and A. Meredith Hughes2 1 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 2 Department of Astronomy, Van Vleck Observatory, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459, USA E-mail contact: mmacgreg at cfa.harvard.edu We have used the Submillimeter Array (SMA) to make 1.3 millimeter observations of the debris disk surrounding HD

33 15115, an F-type star with a putative membership in the β Pictoris moving group. This nearly edge-on debris disk shows an extreme asymmetry in optical scattered light, with an extent almost two times larger to the west of the star than to the east (originally dubbed the “Blue Needle”). The SMA observations reveal resolved emission that we model as a circumstellar belt of thermal dust emission. This belt extends to a radius of 110 AU, coincident with the break in the scattered light profile convincingly seen on the western side of the disk.∼ This outer edge location is consistent with the presence of an underlying population of dust-producing planetesimals undergoing a collisional cascade, as hypothesized in “birth ring” theory. In addition, the millimeter emission shows a 3σ feature aligned with the asymmetric western extension of the scattered light disk. If this millimeter extension is real,∼ then mechanisms for asymmetry that affect only small grains, such as interactions with interstellar gas, are disfavored. This tentative feature might be explained by secular perturbations to grain introduced by neutral gas drag, as previously invoked to explain asymmetric morphologies of other, similar debris disks. Accepted by ApJ http://arxiv.org/pdf/1501.05962v1.pdf

Protoplanetary Disk Masses in the Young NGC 2024 Cluster Rita K. Mann1, Sean M. Andrews2, Josh A. Eisner3, Jonathan P. Williams4, Michael R. Meyer5, James Di Francesco1,6, John M. Carpenter7 , and Doug Johnstone1,6 1 National Research Council Canada, 5071 West Saanich Road, Victoria, BC, Canada V9E 2E7 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3 Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 4 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 USA 5 ETH Z¨urich, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, 8093, Zurich, Switzerland 6 Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 1A1, Canada 7 Department of Astronomy - California Institute of Technology, MC 249-17, Pasadena, CA 91125, USA E-mail contact: rita.mann at nrc-cnrc.gc.ca We present the results from a Submillimeter Array survey of the 887 µm continuum emission from the protoplanetary disks around 95 young stars in the young cluster NGC 2024. Emission was detected from 22 infrared sources, with flux densities from 5 to 330 mJy; upper limits (at 3σ) for the other 73 sources range from 3 to 24 mJy. For standard ∼ assumptions, the corresponding disk masses range from 0.003 to 0.2 M⊙, with upper limits at 0.002–0.01 M⊙. The NGC 2024 sample has a slightly more populated tail∼ at the high end of its disk mass distribution compared to other clusters, but without more information on the nature of the sample hosts it remains unclear if this difference is statistically significant or a superficial selection effect. Unlike in the Orion Trapezium, there is no evidence for a disk mass dependence on the (projected) separation from the massive star IRS2b in the NGC 2024 cluster. We suggest that this is due to either the cluster youth or a comparatively weaker photoionizing radiation field. Accepted by ApJ http://arxiv.org/pdf/1501.06512

The Bolocam Galactic Plane Survey. XI. Temperatures and Substructure of Galactic Clumps Based on 350 µm Observations Manuel Merello1,2, Neal J. Evans II1, Yancy L. Shirley3, Erik Rosolowsky4, Adam Ginsburg5, John Bally6, Cara Battersby7 and Michael M. Dunham7 1 The University of Texas at Austin, Department of Astronomy, 2515 Speedway, Stop C1400, Austin, Texas 78712-1205 2 Istituto di Astrofisica e Planetologia Spaziali-INAF, Via Fosso del Cavaliere 100, I-00133 Roma, Italy 3 Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA 4 Department of Physics, University of Alberta, 4-181 CCIS Edmonton AB T6G 2E1, Canada 5 European Southern Observatory, ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei M¨unchen, Germany 6 CASA, University of Colorado, 389-UCB, Boulder, CO 80309, USA 7 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 78, Cambridge, MA 02138, USA

34 E-mail contact: manuel.merello at iaps.inaf.it We present 107 maps of continuum emission at 350 µm from Galactic molecular clumps. Observed sources were mainly selected from the Bolocam Galactic Plane Survey (BGPS) catalog, with 3 additional maps covering star forming regions in the outer Galaxy. The higher resolution of the SHARC-II images (8.5′′ beam) compared with the 1.1 mm images from BGPS (33′′ beam) allowed us to identify a large population of smaller substructures within the clumps. A catalog is presented for the 1386 sources extracted from the 350 µm maps. The color temperature distribution of clumps based on the two wavelengths has a median of 13.3 K and mean of 16.3 0.4 K, assuming an opacity law index of 1.7. For ± the structures with the best determined color temperatures, the mean ratio of gas temperature, determined from NH3 observations, to dust color temperature is 0.88 and the median ratio is 0.76. About half the clumps have more than two substructures and 22 clumps have more than 10. The fraction of the mass in dense substructures seen at 350 µm compared to the mass of their parental clump is 0.19, and the surface densities of these substructures are, on average, 2.2 times those seen in the clumps identified at∼ 1.1 mm. For a well-characterized sample, 88 structures (31%) exceed a surface density of 0.2 g cm−2, and 18 (6%) exceed 1.0 g cm−2, thresholds for massive star formation suggested by theorists. Accepted by ApJS http://arxiv.org/pdf/1501.05965

Stirring in massive, young debris discs from spatially resolved Herschel images A. Mo´or1, A.´ K´osp´al1,2, P. Abrah´am´ 1, D. Apai3, Z. Balog4, C. Grady5, Th. Henning4, A. Juh´asz6, Cs. Kiss1, A. V. Krivov7, N. Pawellek7 and Gy. M. Szab´o1,8 1 Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Bu- dapest, Hungary 2 European Space Agency (ESA-ESTEC, SRE-S), Noordwijk, The Netherlands 3 Department of Astronomy and Department of Planetary Sciences, The University of Arizona, Tucson, USA 4 Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, 69117 Heidelberg, Germany 5 Exoplanets and Stellar Astrophysics Laboratory, Goddard Space Flight Center, Greenbelt, USA 6 Leiden Observatory, Leiden University, Leiden, The Netherlands 7 Astrophysikalisches Institut und Universit¨atssternwarte, Friedrich-Schiller-Universit¨at Jena, Germany 8 ELTE, Gothard Astrophysical Observatory, Szombathely, Hungary E-mail contact: moor at konkoly.hu A significant fraction of main-sequence stars are encircled by dusty debris discs, where the short-lived dust particles are replenished through collisions between planetesimals. Most destructive collisions occur when the orbits of smaller bodies are dynamically stirred up, either by the gravitational effect of locally formed -sized planetesimals (self- stirring scenario), or via secular perturbation caused by an inner (planetary stirring). The relative importance of these scenarios in debris systems is unknown. Here, we present new Herschel Space Observatory imagery of 11 discs selected from the most massive and extended known debris systems. All discs were found to be extended at far-infrared wavelengths, five of them being resolved for the first time. We evaluated the feasibility of the self-stirring scenario by comparing the measured disc sizes with the predictions of the model calculated for the ages of our targets. We concluded that the self-stirring explanation works for seven discs. However, in four cases, the predicted pace of outward propagation of the stirring front, assuming reasonable initial disc masses, was far too low to explain the radial extent of the cold dust. Therefore, for HD 9672, HD 16743, HD 21997, and HD 95086, another explanation is needed. We performed a similar analysis for β Pic and HR 8799, reaching the same conclusion. We argue that planetary stirring is a promising possibility to explain the disc properties in these systems. In HR 8799 and HD 95086, we may already know the potential perturber, since their known outer giant planets could be responsible for the stirring process. Interestingly, the discs around HD 9672, HD 21997, and β Pic are also unique in harbouring detectable amount of molecular CO gas. Our study demonstrates that among the largest and most massive debris discs self-stirring may not be the only active scenario, and potentially planetary stirring is responsible for destructive collisions and debris dust production in a number of systems. Accepted by MNRAS (447, 577–597) http://arxiv.org/pdf/1411.5829

35 The Multiple Systems in the Young Stellar Cluster Located in the Vicinity of IRAS 05137+3919 Source E. H. Nikoghosyan1 and N. M. Azatyan1 1 Byurakan Astrophysical Observatory, Byurakan vil., Aragatsotn reg., Armenia E-mail contact: elena at bao.sci.am Four binary objects and one triplet have been revealed in the young stellar cluster located in the vicinity of IRAS 05137+3919 source on a distance 4.4 kpc with the use of statistic analysis (2PCF, Poisson statistic). They are including the pair of Ae/Be stars. The percentage of the multiple systems in the cluster is mf = 5 and cp = 10. It should be noticed, that the use of the different databases, namely 2MASS and GPS UKIDSS, which are differ by both photometric limit and resolution, do not affect the value of these parameters. The mass of the multiple systems’ components are located in the range from 1 to 8 Msol and log P (rotation period in years) - from 4.4 to 4.7. The median value of the mass ratio of the components is q = 0.73. The percentage of the multiple systems and their parameters in this cluster is resembling with the data obtained in the other star forming regions (ONC, Perseus, U Sco A), in which the value of mf and cp parameters are comparable with the results obtained for field’s stellar objects. Accepted by Astrophysics http://arxiv.org/pdf/1501.06717

[OI]63 µm jets in class 0 sources detected by Herschel B. Nisini1, G. Santangelo1, T. Giannini1, S. Antoniucci1, S. Cabrit2, C. Codella3, C.J. Davis4, J. Eisl¨offel5, L. Kristensen6, G. Herczeg7, D. Neufeld8 and E.F. van Dishoeck9,10 1 INAF – Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monte Porzio, Italy 2 LERMA, Observatoire de Paris, UMR 8112 of the CNRS, 61 Av. de L’Observatoire, 75014 Paris, France 3 INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy 4 Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK 5 Th¨uringer Landessternwarte, Sternwarte 5, 07778, Tautenburg, Germany 6 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138, USA 7 Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, Beijing 100871, China 8 Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA 9 Sterrewacht Leiden, Leiden University, PO Box 9513, 2300 RA, Leiden, The Netherlands 10 Max-Planck-Institut fr extraterrestriche Physik, Postfach 1312, 85741, Garching, Germany E-mail contact: brunella.nisini at oa-roma.inaf.it We present Herschel PACS mapping observations of the [OI] 63 µm line towards protostellar outflows in the L1448, NGC1333-IRAS4, HH46, BHR71 and VLA1623 star forming regions. We detect emission spatially resolved along the outflow direction, which can be associated with a low excitation atomic jet. In the L1448-C, HH46 IRS and BHR71 IRS1 outflows this emission is kinematically resolved into blue- and red-shifted jet lobes, having radial velocities up to 200 km s−1. In the L1448-C atomic jet the velocity increases with the distance from the protostar, similarly to what observed in the SiO jet associated with this source. This suggests that [OI] and molecular gas are kinematically connected and that this latter could represent the colder cocoon of a jet at higher excitation. Mass flux rates (M˙ jet(OI)) have been measured from the [OI]63 µm luminosity adopting two independent methods. We find values in the range −7 −1 1-4 10 M⊙,yr for all sources but HH46, for which an order of magnitude higher value is estimated. M˙ jet(OI) × are compared with mass accretion rates (M˙ acc) onto the protostar and with M˙ jet derived from ground-based CO observations. M˙ jet(OI)/M˙ acc ratios are in the range 0.05-0.5, similar to the values for more evolved sources. M˙ jet(OI) in HH46 IRS and IRAS4A are comparable to M˙ jet(CO), while those of the remaining sources are significantly lower than the corresponding M˙ jet(CO). We speculate that for these three sources most of the mass flux is carried out by a molecular jet, while the warm atomic gas does not significantly contribute to the dynamics of the system. Accepted by Astrophysical Journal http://arxiv.org/pdf/1501.03681

36 Resonances in retrograde circumbinary discs Chris Nixon1,2 and Stephen H. Lubow3 1 JILA, University of Colorado & NIST, Boulder CO 80309-0440, USA 2 Einstein Fellow 3 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA E-mail contact: chris.nixon at jila.colorado.edu We analyse the interaction of an eccentric binary with a circular coplanar circumbinary disc that rotates in a retrograde sense with respect to the binary. In the circular binary case, no Lindblad resonances lie within the disc and no Lindblad resonant torques are produced, as was previously known. By analytic means, we show that when the binary orbit is eccentric, there exist components of the gravitational potential of the binary which rotate in a retrograde sense to the binary orbit and so rotate progradely with respect to this disc, allowing a resonant interaction to occur between the binary and the disc. The resulting resonant torques distinctly alter the disc response from the circular binary case. We describe results of three-dimensional hydrodynamic simulations to explore this effect and categorise the response of the disc in terms of modes whose strengths vary as a function of binary mass ratio and eccentricity. These mode strengths are weak compared to the largest mode strengths expected in the prograde case where the binary and disc rotate in the same sense. However, for sufficiently high binary eccentricity, resonant torques open a gap in a retrograde circumbinary disc, while permitting gas inflow on to the binary via gas streams. The inflow results in a time varying accretion rate on to the binary that is modulated over the binary , as was previously found to occur in the prograde case. Accepted by MNRAS http://arxiv.org/pdf/1501.07277

A Study of Mid-Infrared Sources that Dramatically Brightened Hiroki Onozato1, Yoshifusa Ita1, Kenji Ono2, Misato Fukagawa3, Kenshi Yanagisawa4, Hideyuki Izumiura4, Yoshikazu Nakada5, and Noriyuki Matsunaga6 1 Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aramaki Aoba, Aoba-ku, Sendai, Miyagi 980-0857 2 Institute for Research, The University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa, Chiba 277-8582 3 Department of Earth and Space Science, Graduate School of Science Osaka University, 1-1 Machikaneyama, Toyon- aka, Osaka 560-0043 4 Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232 5 Kiso Observatory, Institute of Astronomy, School of Science, The University of Tokyo, 10762-30 Mitake, Kiso-machi, Kiso-gun, Nagano 397-0101 6 Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 E-mail contact: h.onozato at astr.tohoku.ac.jp We present results of near-infrared photometric and spectroscopic observations of mid-infrared (MIR) sources that dramatically brightened. Using IRAS, AKARI, and WISE point source catalogs, we found that 4 sources (IRAS 19574+491, V2494 Cyg, IRAS 22343+7501, and V583 Cas) significantly brightened at MIR wavelengths over the 20- 30 years of difference in observing times. Little is known about these sources except V2494 Cyg, which is considered a FU Orionis star. Our observation clearly resolves IRAS 22343+7501 into 4 stars (2MASS J22352345+7517076, 2MASS J22352442+7517037, [RD95] C, and 2MASS J22352497+7517113) and first JHKs photometric data for all 4 sources are obtained. Two of these stars (2MASS J22352442+7517037 and 2MASS J22352497+7517113) are known as T Tau stars. Our spectroscopic observation reveals that IRAS 19574+9441 is an M-type evolved star and V583 Cas is a carbon star. 2MASS J22352345+7517076 is probably a YSO, judging from our observation that it has featureless near-infrared (NIR) spectrum and also showed dramatic brightening in NIR (about 4 magnitudes in Ks-band). The possible reasons for dramatic brightening in MIR are discussed in this paper. Accepted by Pub. Ast. Soc. Japan http://arxiv.org/pdf/1501.05721

37 Detection of a large fraction of atomic gas not associated with star-forming material in M17 SW J.P. P´erez-Beaupuits1, J. Stutzki2, V. Ossenkopf2, M. Spaans3, R. G¨usten1, and H. Wiesemeyer1 1 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, 53121 Bonn, Germany 2 I. Physikalisches Institut der Universit¨at zu K¨oln, Z¨ulpicher Straße 77, 50937 K¨oln, Germany 3 Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, 9747 AV Groningen, The Netherlands E-mail contact: jp at mpifr.de We probe the column densities and masses traced by the ionized and neutral atomic carbon with spectrally resolved maps, and compare them to the diffuse and dense molecular gas traced by [C I] and low-J CO lines toward the star- forming region M17 SW. We mapped a 4.1 pc 4.7 pc region in the [C I] 609 µm line using the APEX telescope, as well as the CO isotopologues with the IRAM 30m× telescope. We analyze the data based on velocity channel maps that are 1 km s−1 wide. We correlate their spatial distribution with that of the [C II] map obtained with SOFIA/GREAT. Optically thin approximations were used to estimate the column densities of [C I] and [C II] in each velocity channel. The spatial distribution of the [C I] and all CO isotopologues emission was found to be associated with that of [C II] in about 20%–80% of the mapped region, with the high correlation found in the central (15–23 km s−1) velocity channels. The excitation temperature of [C I] ranges between 40 K and 100 K in the inner molecular region of M17 SW. Column densities in 1 km s−1 channels between 1015 and 1017 cm−2 were found for [C I]. Just 20% of the velocity range ( 40 km/s) that the [C II] line spans is∼ associated∼ with the star-forming material traced∼ by [C I] and ∼ 3 CO. The total gas mass estimated from the [C II] emission gives a lower limit of 4.4 10 M⊙. At least 64% of this mass is not associated with the star-forming material in M17 SW. We also found that∼ about× 36%, 17%, and 47% of the [C II] emission is associated with the HII, HI, and H2 regimes, respectively. Comparisons with the H41α line shows an ionization region mixed with the neutral and part of the molecular gas, in agreement with the clumped structure and dynamical processes at play in M17 SW. These results are also relevant to extra-galactic studies in which [C II] is often used as a tracer of star-forming material. Accepted by A&A http://arxiv.org/pdf/1501.02735

A cluster in the making: ALMA reveals the initial conditions for high-mass cluster formation J.M. Rathborne1, S. N. Longmore2, J. M. Jackson3, J. F. Alves4, J. Bally5, N. Bastian2, Y. Contreras1, J. B. Foster6, G. Garay7, J. M. D. Kruijssen8, L. Testi9,10,11 and A. J. Walsh12 1 CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW, 1710, Australia 2 Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK 3 Institute for Astrophysical Research, Boston University, Boston, MA 02215, USA 4 University of Vienna, T¨urkenschanzstrasse 17, 1180 Vienna, Austria 5 Center for Astrophysics and Space Astronomy, University of Colorado 6 Department of Astronomy, Yale University, P.O. Box 208101 New Haven, CT 06520-8101, USA 7 Universidad de Chile, Camino El Observatorio1515, Las Condes, Santiago, Chile 8 Max-Planck Institut fur Astrophysik, Karl-Schwarzschild-Strasse 1, 85748, Garching, Germany 9 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei Munchen, Germany 10 INAF-Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy 11 Excellence Cluster Universe, Boltzmannstr. 2, D-85748, Garching, Germany 12 International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, Australia E-mail contact: Jill.Rathborne at csiro.au G0.253+0.016 is a molecular clump that appears to be on the verge of forming a high mass, Arches-like cluster. Here we present new ALMA observations of its small-scale ( 0.07 pc) 3mm dust continuum and molecular line emission. The data reveal a complex network of emission features,∼ the morphology of which ranges from small, compact regions to extended, filamentary structures that are seen in both emission and absorption. The dust column density is well traced by molecules with higher excitation energies and critical densities, consistent with a clump that has a denser interior. A statistical analysis supports the idea that turbulence shapes the observed gas structure within

38 G0.253+0.016. We find a clear break in the turbulent power spectrum derived from the optically thin dust continuum emission at a spatial scale of 0.1 pc, which may correspond to the spatial scale at which gravity has overcome the thermal pressure. We suggest∼ that G0.253+0.016 is on the verge of forming a cluster from hierarchical, filamentary structures that arise from a highly turbulent medium. Although the stellar distribution within Arches-like clusters is compact, centrally condensed and smooth, the observed gas distribution within G0.253+0.016 is extended, with no high-mass central concentration, and has a complex, hierarchical structure. If this clump gives rise to a high-mass cluster and its stars are formed from this initially hierarchical gas structure, then the resulting cluster must evolve into a centrally condensed structure via a dynamical process. Accepted by ApJ http://arxiv.org/pdf/1501.07368

Disentangling the outflow and protostars in HH 900 in the Carina Nebula Megan Reiter1, Nathan Smith1, Megan M. Kiminki1, John Bally2, and Jay Anderson3 1 Steward Observatory, University of Arizona, Tucson, AZ 85721, USA 2 Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309, USA 3 Space Telescope Science Institute, Baltimore, MD 21218, USA E-mail contact: mreiter at as.arizona.edu HH 900 is a peculiar protostellar outflow emerging from a small, tadpole-shaped globule in the Carina nebula. Previous Hα imaging with HST/ACS showed an ionized outflow with a wide opening angle that is distinct from the highly collimated structures typically seen in protostellar jets. We present new narrowband near-IR [Fe II] images taken with the Wide Field Camera 3 on the Hubble Space Telescope that reveal a remarkably different structure than Hα. In contrast to the unusual broad Hα outflow, the [Fe II] emission traces a symmetric, collimated bipolar jet with the morphology and kinematics that are more typical of protostellar jets. In addition, new Gemini adaptive optics images reveal near-IR H2 emission coincident with the Hα emission, but not the [Fe II]. Spectra of these three components trace three separate and distinct velocity components: (1) H2 from the slow, entrained molecular gas, (2) Hα from the ionized skin of the accelerating outflow sheath, and (3) [Fe II] from the fast, dense, and collimated protostellar jet itself. Together, these data require a driving source inside the dark globule that remains undetected behind a large column density of material. In contrast, Hα and H2 emission trace the broad outflow of material entrained by the jet, which is irradiated outside the globule. As it get dissociated and ionized, it remains visible for only a short time after it is dragged into the H II region. Accepted by MNRAS http://arxiv.org/pdf/1501.06564

Probing stellar accretion with mid-infrared hydrogen lines Elisabetta Rigliaco1,2, I. Pascucci1, G. Duchene3, S. Edwards4, D.R. Ardila5, C. Grady6, I. Mendigut´ıa7, B. Montesinos8, G. D. Mulders1, J.R. Najita9, J. Carpenter10, E. Furlan11, U. Gorti12, R. Meijerink13 and M.R. Meyer2 1 Department of , University of Arizona, 1629 E. University Blvd. Tucson, AZ 85719, USA 2 Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich, Switzerland 3 Astronomy Department, University of California, Berkeley, Hearst Field Annex B-20, Berkeley CA 94720-3411, USA 4 Five College Astronomy Department, Smith College, Northampton, MA 01063, USA 5 NASA Herschel Science Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125, USA 6 Exoplanets and Stellar Astrophysics Lab, Code 667, GoddardSpace Flight Center, Greenbelt, MD 20771 7 School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK 8 Departamento de Astrof´ısica, Centro de Astrobiolog´ıa, ESAC Campus, PO Box 78, 28691 Villanueva de la Ca˜nada, Madrid, Spain 9 National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719, USA 10 Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125, USA 11 Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA

39 91125, USA 12 NASA Ames Research Center, Moffett Field, CA, USA 13 Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA, Leiden, The Netherlands E-mail contact: elisabetta.rigliaco at phys.ethz.ch In this paper we investigate the origin of the mid-infrared (IR) hydrogen recombination lines for a sample of 114 disks in different evolutionary stages (full, transitional and debris disks) collected from the Spitzer archive. We focus on the two brighter H i lines observed in the Spitzer spectra, the H i(7-6) at 12.37µm and the H i(9-7) at 11.32µm. We detect the H i(7-6) line in 46 objects, and the H i(9-7) in 11. We compare these lines with the other most common gas line detected in Spitzer spectra, the [Ne ii] at 12.81µm. We argue that it is unlikely that the H i emission originates from the photoevaporating upper surface layers of the disk, as has been found for the [Ne ii] lines toward low-accreting stars. Using the H i(9-7)/H i(7-6) line ratios we find these gas lines are likely probing gas with hydrogen column densities of 1010-1011 cm−3. The subsample of objects surrounded by full and transitional disks show a positive correlation between the accretion luminosity and the H i line luminosity. These two results suggest that the observed mid-IR H i lines trace gas accreting onto the star in the same way as other hydrogen recombination lines at shorter wavelengths. A pure chromospheric origin of these lines can be excluded for the vast majority of full and transitional disks. We report for the first time the detection of the H i(7-6) line in eight young (< 20 Myr) debris disks. A pure chromospheric origin cannot be ruled out in these objects. If the H i(7-6) line traces accretion in these older systems, as in the case −10 of full and transitional disks, the strength of the emission implies accretion rates lower than 10 M⊙/yr. We discuss some advantages of extending accretion indicators to longer wavelengths, and the next steps required to pin down the origin of mid-infrared hydrogen lines. Accepted by ApJ http://arxiv.org/pdf/1501.06210v1.pdf

New Pre-main-Sequence Stars in the Upper Scorpius Subgroup of Sco-Cen A.C. Rizzuto1,2, M.J. Ireland3, A.L. Kraus1 1 Department of Astronomy, University of Texas, 2515 Speedway, Stop C1400, Austin, Texas 78712, USA 2 Department of Physics and Astronomy, Macquarie University, Sydney NSW, 2109, Australia 3 Research School of Astronomy & Astrophysics, Australian National University, Canberra, ACT 2611, Australia E-mail contact: aaron.rizzuto23 at gmail.com We present 237 new spectroscopically confirmed pre-main-sequence K and M-type stars in the young Upper Scorpius subgroup of the Sco-Cen association, the nearest region of recent massive star formation. Using the Wide-Field Spectrograph at the Australian National University 2.3 m telescope at Siding Spring, we observed 397 kinematically and photometrically selected candidate members of Upper Scorpius, and identified new members by the presence of Lithium absorption. The HR-diagram of the new members shows a spread of ages, ranging from 3–20 Myr, which broadly agrees with the current age estimates of 5–10 Myr. We find a significant range of Li 6708∼ equivalent widths among the members, and a minor dependence of∼ HR-diagram position on the measured equivalent width of the Li 6708A line, with members that appear younger having more Lithium. This could indicate the presence of either populations of different age, or a spread of ages in Upper Scorpius. We also use Wide-Field Infrared Survey Explorer data to infer circumstellar disk presence in 25 of the members on the basis of infrared excesses, including two candidate transition disks. We find that 11.2 3.4% of the M0-M2 spectral type (0.4–0.8 M⊙) Upper Sco stars display an excess that indicates the presence of a gaseous± disk. Accepted by MNRAS http://arxiv.org/pdf/1501.07270

New Spatially Resolved Observations of the T Cha Transition Disk and Constraints on the Previously Claimed Substellar Companion S. Sallum1, J.A. Eisner1, Laird M. Close1, Philip M. Hinz1, Andrew J. Skemer1, Vanessa Bailey1, Runa Briguglio2, Katherine B. Follette1, Jared R. Males1,4, Katie M. Morzinski1,4, Alfio Puglisi2, Timothy J. Rodigas3, Alycia J. Weinberger3, Marco Xompero2

40 1 Astronomy Department, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA 2 INAF-Osservatorio Astrofisico di Arcetri, I-50125, Firenze, Italy 3 Carnegie Institution DTM, 5241 Broad Branch Rd, Washington, DC 20015, USA 4 NASA Sagan Fellow E-mail contact: ssallum at email.arizona.edu We present multi-epoch non-redundant masking observations of the T Cha transition disk, taken at the VLT and ′ Magellan in H, Ks, and L bands. T Cha is one of a small number of transition disks that host companion candidates discovered by high-resolution imaging techniques, with a putative companion at a position angle of 78◦, separation of 62 mas, and contrast of ∆L′ of 5.1 mag. We find comparable binary parameters in our re-reduction of the initial ′ ′ detection images, and similar parameters in the 2011 L , 2013 NaCo L , and 2013 NaCo Ks data sets. We find a close-in companion signal in the 2012 NaCo L′ dataset that cannot be explained by orbital motion, and a non-detection in the 2013 MagAO/Clio2 L′ data. However, Monte-carlo simulations show that the best fits to the 2012 NaCo and 2013 MagAO/Clio2 followup data may be consistent with noise. There is also a significant probability of false non- detections in both of these data sets. We discuss physical scenarios that could cause the best fits, and argue that previous companion and scattering explanations are inconsistent with the results of the much larger dataset presented here. Accepted by ApJ http://arxiv.org/pdf/1501.01964

A Continuum of Planet Formation Between 1 and 4 Earth Radii Kevin C. Schlaufman1,2 1 Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA E-mail contact: kschlauf at mit.edu It has long been known that stars with high are more likely to host giant planets than stars with low metal- licity. Yet the connection between host star metallicity and the properties of small planets is only just beginning to be investigated. It has recently been argued that the metallicity distribution of stars with candidates identified by Kepler provides evidence for three distinct clusters of exoplanets, distinguished by planet radius boundaries at 1.7 R⊕ and 3.9 R⊕. This would suggest that there are three distinct planet formation pathways for super-, mini- , and giant planets. However, as I show through three independent analyses, there is actually no evidence for the proposed radius boundary at 1.7 R⊕. On the other hand, a more rigorous calculation demonstrates that a single, continuous relationship between planet radius and metallicity is a better fit to the data. The planet radius and metallicity data therefore provides no evidence for distinct categories of small planets. This suggests that the planet formation process in a typical produces a continuum of planet sizes between 1 R⊕ and 4 R⊕. As a result, the currently available planet radius and metallicity data for solar-metallicity F and G stars give no reason to expect that the amount of solid material in a protoplanetary disk determines whether super-Earths or mini-Neptunes are formed. Accepted by ApJL http://arxiv.org/pdf/1501.05953

Understanding star formation in molecular clouds I. Effects of line-of-sight contamina- tion on the column density structure N. Schneider1,2, V. Ossenkopf3, T. Csengeri4, R.S. Klessen5,6,7, C. Federrath8,9, P. Tremblin10,11, P. Girichidis12, S. Bontemps1,2, Ph. Andr´e13 1 Univ. Bordeaux, LAB, UMR 5804, 33271 Floirac, France 2 CNRS, LAB, UMR 5804, 33271 Floirac, France 3 I. Physik. Institut, Universit¨at zu K¨oln, 50937 K¨oln, Germany 4 Max-Planck Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, Bonn, Germany 5 Zentrum f¨ur Astronomie, Institut f¨ur Theoretische Astrophysik, 69120 Heidelberg, Germany

41 6 Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, USA 7 Department of Astronomy and Astrophysics, University of California, Santa Cruz, USA 8 Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Australia 9 Research School of Astronomy & Astrophysics, The Australian National University, Canberra, Australia 10 Astrophysics Group, University of Exeter, UK 11 Maison de la Simulation, CEA-CNRS-INRIA-UPS-UVSQ, USR 3441, CEA Saclay, France 12 Max-Planck Institut f¨ur Astrophysik, 85741 Garching, Germany 13 IRFU/SAp CEA/DSM, Laboratoire AIM CNRS - Universit´eParis Diderot, France E-mail contact: nicola.schneider at obs.u-bordeaux1.fr Column-density maps of molecular clouds are one of the most important observables in the context of molecular cloud- and star-formation (SF) studies. With the Herschel satellite it is now possible to precisely determine the column density from dust emission, which is the best tracer of the bulk of material in molecular clouds. However, line-of-sight (LOS) contamination from fore- or background clouds can lead to overestimating the dust emission of molecular clouds, in particular for distant clouds. This implies values that are too high for column density and mass, which can potentially lead to an incorrect physical interpretation of the column density probability distribution function (PDF). In this paper, we use observations and simulations to demonstrate how LOS contamination affects the PDF. We apply a first-order approximation (removing a constant level) to the molecular clouds of and Maddalena (low-mass star-forming), and Carina and NGC3603 (both high-mass SF regions). In perfect agreement with the simulations, we find that the PDFs become broader, the peak shifts to lower column densities, and the power-law tail of the PDF for higher column densities flattens after correction. All corrected PDFs have a lognormal part for low column densities with a peak at AV 2 mag, a deviation point (DP) from the lognormal at AV (DP) 4–5 mag, and a power-law tail for higher column densities.∼ Assuming an equivalent spherical density distribution ρ ∼ r−α, the slopes of the power-law ∝ tails correspond to αP DF = 1.8, 1.75, and 2.5 for Auriga, Carina, and NGC3603. These numbers agree within the uncertainties with the values of α 1.5, 1.8, and 2.5 determined from the slope γ (with α = 1 γ) obtained from the radial column density profiles (≈N rγ ). While α 1.5–2 is consistent with a structure dominated− by collapse (local free-fall collapse of individual cores∝ and clumps and∼ global collapse), the higher value of α > 2 for NGC3603 requires a physical process that leads to additional compression (e.g., expanding ionization fronts). From the small sample of our study, we find that clouds forming only low-mass stars and those also forming high-mass stars have slightly different values for their average column density (1.8 1021cm−2 vs. 3.0 1021cm−2), and they display differences in the overall column density structure. Massive clouds assemble more gas in smaller cloud volumes than low-mass SF ones. However, for both cloud types, the transition of the PDF from lognormal shape into power-law tail is found at the same column density (at AV 4–5 mag). Low-mass and high-mass SF clouds then have the same low column density distribution, most likely dominated∼ by supersonic turbulence. At higher column densities, collapse and external pressure can form the power-law tail. The relative importance of the two processes can vary between clouds and thus lead to the observed differences in PDF and column density structure. Accepted by Astronomy & Astrophysics http://arxiv.org/pdf/1403.2996

An Emerging Wolf-Rayet Massive in NGC 4449 Kimberly R. Sokal1, Kelsey E. Johnson1,2, Remy Indebetouw1,2 and Amy E. Reines2,3,4 1 Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903, USA 2 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA 3 currently Hubble Fellow at Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA E-mail contact: krs9tb at virginia.edu We present a panchromatic investigation of the partially-embedded, emerging massive cluster Source 26 (= S26) in NGC 4449 with optical spectra obtained at Apache Point Observatory and archival Hubble, Spitzer, and Herschel Space Telescope images. First identified as a radio continuum source with a thermal component due to ionized material, the massive cluster S26 also exhibits optical Wolf-Rayet (WR) emission lines that reveal a large evolved massive star population. We find that S26 is host to 240 massive stars, of which 18 are Wolf-Rayet stars; the relative populations are roughly consistent with other observed∼ massive star forming clusters∼ and galaxies. We construct SEDs over two spatial scales ( 100 pc and 300 pc) that clearly exhibit warm dust and polycyclic aromatic hydrocarbon (PAH) ∼ ∼

42 emission. The best fit dust and grain models reveal that both the intensity of the exciting radiation and PAH grain destruction increase toward the cluster center. Given that the timescale of evacuation is important for the future dynamical evolution of the cluster, it is important to determine whether O- and WR stars can evacuate the material gradually before supernova do so on a much faster timescale. With a minimum age of 3 Myr, it is clear that S26 has not yet fully evacuated its natal material, which indicates that unevolved O-type stars≈ alone do not provide sufficient feedback to remove the gas and dust. We hypothesize that the feedback of WR stars in this cluster may be necessary for clearing the material from the gravitational potential of the cluster. We find S26 is similar to Emission Line Clusters observed in the Antennae Galaxies and may be considered a younger analog to 30 Doradus in the LMC. Accepted by AJ http://arxiv.org/pdf/1501.05313

CSI 2264: Characterizing Young Stars in NGC 2264 with Short-Duration, Periodic Flux Dips in their Light Curves John Stauffer1, Ann Marie Cody1,20, Pauline McGinnis6, Luisa Rebull1, Lynne Hillenbrand2, Neal Turner3, John Carpenter2, Peter Plavchan1, Sean Carey1, Susan Terebey4, Maria Morales-Calderon5, Silvia Alencar6, Jerome Bouvier7, Laura Venuti7, Lee Hartmann8, Nuria Calvet8, Giusi Micela9, Ettore Flaccomio9, Inseok Song10, Rob Gutermuth11, David Barrado5, Frederick Vrba12, Kevin Covey13, Deb- bie Padgett14, William Herbst15, Edward Gillen16, Wladimir Lyra3,18, Marcelo Medeiros Guimaraes19, Herve Bouy5 and Fabio Favata17 1 Spitzer Science Center, Caltech MS314-6, Pasadena, CA 91125 USA 2 Astronomy Dept, Caltech, Pasadena, CA 91125, USA 3 Jet Propulsion Laboratory, Caltech, Pasadena, CA 91109, USA 4 Dept. of Physics and Astronomy, 5151 State University Dr., Cal. State University at Los Angeles, Los Angeles, CA 90032, USA 5 Centro de Astrobiologia, Dpto. de Astofisicia, INTA-CSIC, Villanueva de la Canada, Madrid, Spain 6 Dept. de Fisica-ICEx - UFMG, Av. Antonio Carlos, 6627, Belo Horizonte, MG, Brazil 7 Univ. de Grenoble, IPAG, F-38000 Grenoble, France 8 Dept. of Astronomy, Univ. of Michigan, 500 Church St., Ann Arbor, MI 48105, USA 9 INAF-Osservatorio Astronomico di Palermo, Piazza del Parliamento 1, 90134, Palermo, Italy 10 Dept. of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA 11 Dept. of Astronomy, University of Massachusetts, Amherst, MA 01003, USA 12 U.S. Naval Observatory, Flagstaff Station, 10391 W. Naval Obs. Road, Flagstaff, AZ 86001, USA 13 Dept. of Physics and Astronomy, Western Washington Univ., 516 High St., Bellingham, WA 98225, USA 14 NASA/Goddard Space Flight Center, Code 665, Greenbelt, MD 20771, USA 15 Astronomy Dept., Wesleyan University, Middletown, CT 06459, USA 16 Dept. of Physics, University of Oxford, Keble Rd., Oxford, OX1 3RH, UK 17 European Space Agency, 8-10 rue Mario Nikis, F-75738 Paris, France 18 NASA Sagan Fellow 19 Dept. de Fisica e Matematica - UFSJ - Rodovio MG 443, KM 7, 36420-000 Ouro Branco, MG, Brazil 20 NASA Ames Research Center, Kepler Science Office, Mountain View, CA 94035, USA E-mail contact: stauffer at ipac.caltech.edu We identify nine young stellar objects (YSOs) in the NGC 2264 star-forming region with optical CoRoT light curves exhibiting short-duration, shallow, periodic flux dips. All of these stars have infrared (IR) excesses that are consistent with their having inner disk walls near the Keplerian co-rotation radius. The repeating photometric dips have FWHM generally less than one day, depths almost always less than 15%, and periods (3

43 with light curves exhibiting this behavior to other classes of YSO in NGC 2264. A number of physical mechanisms could locally increase the dust scale height near the inner disk wall, and we discuss several of those mechanisms; the most plausible mechanisms are either a disk warp due to interaction with the stellar magnetic field or dust entrained in funnel-flow accretion columns arising near the inner disk wall. Accepted by Astronomical Journal http://arxiv.org/pdf/1501.06609

Dissipation of magnetic fields in star-forming clouds with different Hajime Susa1, Kentaro Doi1, and Kazuyuki Omukai2 1 Department of Physics, Konan University, Okamoto, Kobe, Japan 2 Astronomical Institute, Tohoku University, Aramaki, Sendai, Japan E-mail contact: susa at konan-u.ac.jp

We study dissipation process of magnetic fields in the metallicity range 0–1 Z⊙ for contracting prestellar cloud cores. By solving non-equilibrium chemistry for important charged species including charged grains, we evaluate the drift velocity of the magnetic-field lines with respect to the gas. We find that the magnetic flux dissipates in the density 12 −3 17 −3 range 10 cm < nH < 10 cm for the solar-metallicity case at the scale of the core, which is assumed to be the Jeans scale. The dissipation∼ ∼ density range becomes narrower for lower metallicity. The magnetic field is always frozen −7 −6 to the gas below metallicity <10 –10 Z⊙, depending on the ionization rate by cosmic rays and/or radioactivity. With the same metallicity, the∼ dissipation density range becomes wider for lower ionization rate. The presence of such a dissipative regime is expected to cause various dynamical phenomena in protostellar evolution such as the suppression of jet/outflow launching and fragmentation of the circumstellar disks depending on the metallicity. Accepted by ApJ http://arxiv.org/pdf/1501.00087

Abundance Differences Between Exoplanet Binary Host Stars XO-2N and XO-2S – Dependence on Stellar Parameters Johanna K. Teske1, Luan Ghezzi2, Katia Cunha3,4, Verne V. Smith5, Simon Schuler6 and Maria Bergemann7 1 Carnegie DTM/OCIW, Carnegie Origins Fellow, USA 2 Harvard SAO, USA 3 Steward Observatory, University of Arizona, USA 4 Observatorio Nacional, Mexico 5 NOAO, USA 6 University of Tampa, USA 7 MPIA, Germany E-mail contact: jteske at carnegiescience.edu The chemical composition of exoplanet host stars is an important factor in understanding the formation and character- istics of their orbiting planets. The best example of this to date is the planet-metallicity correlation. Other proposed correlations are thus far less robust, in part due to uncertainty in the chemical history of stars pre- and post-planet formation. Binary host stars of similar type present an opportunity to isolate the effects of planets on host star abundances. Here we present a differential elemental abundance analysis of the XO-2 stellar binary, in which both G9 stars host giant planets, one of which is transiting. Building on our previous work, we report 16 elemental abundances and compare the (XO-2N-XO-S) values to elemental condensation temperatures. The (N-S) values and slopes with condensation temperature resulting from four different pairs of stellar parameters are compared to explore the effects of changing the relative temperature and gravity of the stars. We find that most of the abundance differences between the stars depend on the chosen stellar parameters, but that Fe, Si, and potentially Ni are consistently enhanced in XO-2N regardless of the chosen stellar parameters. This study emphasizes the power of binary host star abundance analysis for probing the effects of giant planet formation, but also illustrates the potentially large uncertainties in abundance differences and slopes induced by changes in stellar temperature and gravity.

44 Accepted by Astrophysical Journal Letters http://arxiv.org/pdf/1501.02167

Characterizing the formation channels from the IMF and binary-star dy- namics Ingo Thies1, Jan Pflamm-Altenburg1, Pavel Kroupa1 and Michael Marks1 1 Helmholtz-Institut f¨ur Strahlen- und Kernphysik, Universit¨at Bonn, Nussallee 14-16, 53115 Bonn, Germany E-mail contact: ithies at astro.uni-bonn.de The stellar initial mass function (IMF) is a key property of stellar populations. There is growing evidence that the classical star-formation mechanism by the direct cloud fragmentation process has difficulties to reproduce the observed abundance and binary properties of brown dwarfs and very-low-mass stars. In particular, recent analytical derivations of the stellar IMF exhibit a deficit of brown dwarfs compared to observational data. Here we derive the residual mass function of brown dwarfs as an empirical measure of the brown dwarf deficiency in recent star-formation models with respect to observations and show that it is compatible with the substellar part of the Thies-Kroupa-IMF and the mass function obtained by numerical simulations. We conclude that the existing models may be further improved by including a substellar correction term accounting for additional formation channels like disk or filament fragmentation. The term “peripheral fragmentation” is introduced here for such additional formation channels. In addition, we present an updated analytical model of stellar and substellar binarity. The resulting binary fraction as well as the dynamically evolved companion mass-ratio distribution are in good agreement with observational data on stellar and very-low-mass binaries in the Galactic field, in clusters, and in dynamically unprocessed groups of stars if all stars form as binaries with stellar companions. Cautionary notes are given on the proper analysis of mass functions and the companion- mass-ratio distribution and the interpretation of the results. The existence of accretion disks around young brown dwarfs does not imply these form just like stars in direct fragmentation. Accepted by The Astrophysical Journal http://arxiv.org/pdf/1501.01640

Kinematic and Spatial Substructure in NGC 2264 John J. Tobin1,4, Lee Hartmann2, Gabor F˝ur´esz3, Wen-Hsin Hsu2, Mario Mateo2 1 Hubble Fellow, National Radio Astronomy Observatory, Charlottesville, VA 22903, USA 2 Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA 3 Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 4 Current Address: Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden, The Netherlands E-mail contact: tobin at strw.leidenuniv.nl We present an expanded kinematic study of the young cluster NGC 2264 based upon optical radial velocities measured using multi-fiber echelle spectroscopy at the 6.5 meter MMT and Magellan telescopes. We report radial velocities for 695 stars, of which approximately 407 stars are confirmed or very likely members. Our results more than double the number of members with radial velocities from F˝ur´esz et al., resulting in a much better defined kinematic relationship between the stellar population and the associated molecular gas. In particular, we find that there is a significant subset of stars that are systematically blueshifted with respect to the molecular (13CO) gas. The detection of Lithium absorption and/or infrared excesses in this blue-shifted population suggests that at least some of these stars are cluster members; we suggest some speculative scenarios to explain their kinematics. Our results also more clearly define the redshifted population of stars in the northern end of the cluster; we suggest that the stellar and gas kinematics of this region are the result of a bubble driven by the wind from O7 star S Mon. Our results emphasize the complexity of the spatial and kinematic structure of NGC 2264, important for eventually building up a comprehensive picture of cluster formation. Accepted by AJ http://arxiv.org/pdf/1501.03172

45 Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Mag- netohydrodynamic Effects and Early Formation of Circumstellar Disks Kengo Tomida1, Satoshi Okuzumi2 and Masahiro N. Machida3 1 Princeton University, 4 Ivy Lane, Princeton, NJ 08540, USA 2 Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8551, Japan 3 Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan E-mail contact: tomida at astro.princeton.edu The transport of angular momentum by magnetic fields is a crucial physical process in formation and evolution of stars and disks. Because the ionization degree in star forming clouds is extremely low, non-ideal magnetohydrodynamic (MHD) effects such as ambipolar diffusion and Ohmic dissipation work strongly during protostellar collapse. These effects have significant impacts in the early phase of star formation as they redistribute magnetic flux and suppress angular momentum transport by magnetic fields. We perform three-dimensional nested-grid radiation magnetohydro- dynamic (RMHD) simulations including Ohmic dissipation and ambipolar diffusion. Without these effects, magnetic fields transport angular momentum so efficiently that no rotationally supported disk is formed even after the second collapse. Ohmic dissipation works only in a relatively high density region within the first core and suppresses angular momentum transport, enabling formation of a very small rotationally supported disk after the second collapse. With both Ohmic dissipation and ambipolar diffusion, these effects work effectively in almost the entire region within the first core and significant magnetic flux loss occurs. As a result, a rotationally supported disk is formed even before a protostellar core forms. The size of the disk is still small, about 5 AU at the end of the first core phase, but this disk will grow later as gas accretion continues. Thus the non-ideal MHD effects can resolve the so-called magnetic braking catastrophe while maintaining the disk size small in the early phase, which is implied from recent interferometric observations. Accepted by The Astrophysical Journal http://arxiv.org/pdf/1501.04102

Type I Planet Migration in a Magnetized Disk. I. Effect of Large-Scale Vertical and Azimuthal Field Components Ana Uribe1, Alissa Bans1,2, and Arieh K¨onigl1 1 Department of Astronomy and Astrophysics, University of Chicago, Chicago IL 60637, USA 2 present address: Astronomy Department, Adler Planetarium, Chicago, IL 60605, USA E-mail contact: auribe at oddjob.uchicago.edu We study the effects of a large-scale, ordered magnetic field in protoplanetary disks on Type I planet migration using a combination of numerical simulations in 2D and 3D and a linear perturbation analysis. Steady-state models of such disks require the inclusion of magnetic diffusivity. To make progress using ideal MHD, we focus on simplified field configurations, involving purely vertical (Bz) and azimuthal (Bφ) field components and a combination of the two. For each of the models we calculate the locations of the relevant resonances and of the turning points, which delineate the propagation regions of the MHD waves that transport angular momentum from the planet to the disk. We use both numerical and semianalytic methods to evaluate the cumulative back torque acting on the planet, and explore the effect of spatial gradients in the disk’s physical variables on the results. We conclude that, under realistic (3D) circumstances, a large-scale magnetic field can slow down the inward migration that characterizes the underlying unmagnetized disk — by up to a factor of 2 when the magnetic pressure approaches the thermal pressure — but it ∼ cannot reverse it. A previous inference that a pure-Bφ field whose amplitude decreases fast enough with radius leads to outward migration applies only in 2D. In fact, we find that, in 3D, a pure-Bφ disk undergoes a rapid transition to turbulence on account of a magnetorotational instability that is triggered by the planet-induced appearance of a weak Bz component. Accepted by ApJ http://arxiv.org/pdf/1501.02742

46 Magnetic Fields and Galactic Star Formation Rates Sven Van Loo1,2, Jonathan C. Tan3 and Sam A. E. G. Falle4 1 School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3 Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611, USA 4 Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT, UK E-mail contact: physvl at leeds.ac.uk The regulation of galactic-scale star formation rates (SFRs) is a basic problem for theories of galaxy formation and evolution: which processes are responsible for making observed star formation rates so inefficient compared to maximal rates of gas content divided by dynamical timescale? Here we study the effect of magnetic fields of different strengths on the evolution of giant molecular clouds (GMCs) within a kiloparsec patch of a disk galaxy and resolving scales 5 −3 down to 0.5 pc. Including an empirically motivated prescription for star formation from dense gas (nH > 10 cm ) at an efficiency≃ of 2% per local free-fall time, we derive the amount of suppression of star formation by magnetic fields compared to the nonmagnetized case. We find GMC fragmentation, dense clump formation and SFR can be significantly affected by the inclusion of magnetic fields, especially in our strongest investigated B-field case of 80 µG. However, our chosen kpc-scale region, extracted from a global galaxy simulation, happens to contain a starbursting cloud complex that is only modestly affected by these magnetic fields and likely requires internal star formation feedback to regulate its SFR. Accepted by ApJ Letters http://arxiv.org/pdf/1411.7548

New Extinction and Mass Estimates from Optical Photometry of the Very Low Mass Brown Dwarf Companion CT Chamaeleontis B with the Magellan AO System Ya-Lin Wu1, Laird M. Close1, Jared R. Males1, Travis S. Barman2, Katie M. Morzinski1, Katherine B. Follette1, Vanessa Bailey1, Timothy J. Rodigas1,3, Philip Hinz1, Alfio Puglisi4, Marco Xompero4, Runa Briguglio4 1 Steward Observatory, University of Arizona, Tucson, Arizona 85721, USA 2 Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, USA 3 Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015, USA 4 INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze, Italy E-mail contact: yalinwu at email.arizona.edu We used the Magellan adaptive optics (MagAO) system and its VisAO CCD camera to image the young low mass brown dwarf companion CT Chamaeleontis B for the first time at visible wavelengths. We detect it at r′, i′, z′, and YS. With our new photometry and Teff 2500 K derived from the shape its K-band spectrum, we find that CT Cha ∼ B has AV = 3.4 1.1 mag, and a mass of 14–24 MJ according to the DUSTY evolutionary tracks and its 1–5 Myr age. The overluminosity± of our r′ detection indicates that the companion has significant Hα emission and a mass accretion −10 −1 rate 6 10 M⊙ yr , similar to some substellar companions. Proper motion analysis shows that another point source∼ within× 2′′ of CT Cha A is not physical. This paper demonstrates how visible wavelength AO photometry (r′, i′, ′ z , YS) allows for a better estimate of extinction, luminosity, and mass accretion rate of young substellar companions. Accepted by ApJ http://arxiv.org/pdf/1501.01396

APEX-CHAMP+ high-J CO observations of low–mass young stellar objects: IV. Mechanical and radiative feedback U. A. Yıldız1,2, L. E. Kristensen3, E. F. van Dishoeck1,4, M. R. Hogerheijde1, A. Karska4, A. Belloche5, A. Endo6, W. Frieswijk7,8, R. Guesten5, T. A. van Kempen1, S. Leurini5, Z. Nagy9, J. P. P´erez- Beaupuits5, C. Risacher5,7, N. van der Marel1, R. J. van Weeren3 and F. Wyrowski5

47 1 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands 2 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA, 91109, USA 3 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 4 Max-Planck-Institut f¨ur Extraterrestrische Physik (MPE), Giessenbachstrasse 1, 85748 Garching, Germany 5 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, D-53121, Bonn, Germany 6 Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, the Netherlands 7 Kapteyn Institute, University of Groningen, Landleven 12, 9747 AD, Groningen, the Netherlands 8 ASTRON, Oude Hoogeveensedijk 4, 7991 PD, Dwingeloo, the Netherlands 9 I. Physikalisches Institut der Universit¨at zu K¨oln, Z¨ulpicher Strasse 77, 50937 K¨oln, Germany E-mail contact: Umut.Yildiz at jpl..gov Context. During the embedded stage of star formation, bipolar molecular outflows and UV radiation from the protostar are important feedback processes. Both processes reflect the accretion onto the forming star and affect subsequent collapse or fragmentation of the cloud. Aims. Our aim is to quantify the feedback, mechanical and radiative, for a large sample of low-mass sources in a consistent manner. The outflow activity is compared to radiative feedback in the form of UV heating by the accreting protostar to search for correlations and evolutionary trends. Methods. Large-scale maps of 26 young stellar objects, which are part of the Herschel WISH key program are obtained + 12 13 using the CHAMP instrument on the Atacama Pathfinder EXperiment ( CO and CO 6–5; Eup 100 K), and the 12 13 ∼ HARP-B instrument on the James Clerk Maxwell Telescope ( CO and CO 3–2; Eup 30 K). The maps have high spatial resolution, particularly the CO 6–5 maps taken with a 9′′ beam, resolving the morphology∼ of the outflows. The maps are used to determine outflow parameters and the results are compared with higher-J CO lines obtained with Herschel. Envelope models are used to quantify the amount of UV-heated gas and its temperature from 13CO 6–5 observations. Results. All sources in our sample show outflow activity, with the spatial extent decreasing from the Class 0 to the Class I stage. Consistent with previous studies, the outflow force, FCO, is larger for Class 0 sources than for Class I sources, even if their luminosities are comparable. The outflowing gas typically extends to much greater distances than the power-law envelope and therefore influences the surrounding cloud material directly. Comparison of the CO 6–5 results with HIFI H2O and PACS high-J CO lines, both tracing currently shocked gas, shows that the two components are linked, even though the transitions do not probe the same gas. The link does not extend down to CO 3–2. The conclusion is that CO 6–5 depends on the shock characteristics (density and velocity), whereas CO 3–2 is more sensitive to conditions in the surrounding environment (density). The radiative feedback is responsible for increasing the gas temperature by a factor of two, up to 30–50 K, on scales of a few thousand AU, particularly along the direction of the outflow. The mass of the UV heated gas exceeds the mass contained in the entrained outflow in the inner 3000 AU and is therefore at least as important on small scales. ∼ Accepted by Astronomy & Astrophysics http://arxiv.org/pdf/1501.03259

Environment and Protostellar Evolution Yichen Zhang1,2 and Jonathan Tan3,4 1 Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago, Chile 2 Department of Astronomy, Yale University, New Haven, CT 06520, USA 3 Department of Astronomy, University of Florida, Gainesville, Florida 32611, USA 4 Department of Physics, University of Florida, Gainesville, Florida 32611, USA E-mail contact: yczhang.astro at gmail.com Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface density, on protostellar evolution and appearance, focussing on low-mass, Sun-like stars and considering a range of conditions from relatively low pressure filaments in Taurus, to intermediate pressures of cluster-forming clumps like the Orion Nebula Cluster (ONC), to very high pressures that may be found in the densest Infrared Dark Clouds (IRDCs) or in the Galactic Center (GC). We present unified analytic and numerical models for collapse of prestellar cores, accretion disks, protostellar evolution and bipolar outflows, coupled to radiative transfer (RT) calculations and

48 a simple astrochemical model to predict CO gas phase abundances. Prestellar cores in high pressure environments are smaller and denser and thus collapse with higher accretion rates and efficiencies, resulting in higher luminosity protostars with more powerful outflows. The protostellar envelope is heated to warmer temperatures, affecting infrared morphologies (and thus classification) and astrochemical processes like CO depletion to dust grain ice mantles (and thus CO morphologies). These results have general implications for star and planet formation, especially via their effect on astrochemical and dust grain evolution during infall to and through protostellar accretion disks. Accepted by ApJL http://arxiv.org/pdf/1411.0762

Abstracts of recently accepted major reviews

The formation of the solar system S. Pfalzner1, M.B. Davies2, M. Gounelle3,4, A. Johansen2, C. M¨unker5, P. Lacerda6, S. Portegies Zwart7, L. Testi8, M. Trieloff9 and D. Veras10 1 MPIfR, Auf dem Huegel 69, 53121 Bonn, Germany 2 Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, 22100 Lund, Sweden 3 IMPMC, Mus´eum National d’Histoire Naturelle, Sorbonne Universit´es, CNRS, UPMC & IRD, 57 rue Cuvier, 75005 Paris, France 4 Institut Universitaire de France, 103 boulevard Saint-Michel, 75005 Paris, France 5 Institut f¨ur Geologie und Mineralogie, Universit¨at zu K¨oln, Z¨ulpicherstr. 49b 50674 K¨oln, Germany 6 MPI f¨ur Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 G¨ottingen, Germany 7 Leiden University, Sterrewacht Leiden, PO-Box 9513, 2300 RA Leiden, the Netherlands 8 ESO, Karl Schwarzschild str. 2, D-85748 Garching, Germany 9 Institut f¨ur Geowissenschaften, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany 10 Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom E-mail contact: spfalzner at mpifr.de The solar system started to form about 4.56 Gyr ago and despite the long intervening time span, there still exist several clues about its formation. The three major sources for this information are meteorites, the present solar system structure and the planet-forming systems around young stars. In this introduction we give an overview of the current understanding of the solar system formation from all these different research fields. This includes the question of the lifetime of the solar protoplanetary disc, the different stages of planet formation, their duration, and their relative importance. We consider whether meteorite evidence and observations of protoplanetary discs point in the same direction. This will tell us whether our solar system had a typical formation history or an exceptional one. There are also many indications that the solar system formed as part of a star cluster. Here we examine the types of cluster the Sun could have formed in, especially whether its stellar density was at any stage high enough to influence the properties of today’s solar system. The likelihood of identifying siblings of the Sun is discussed. Finally, the possible dynamical evolution of the solar system since its formation and its future are considered. Accepted by Physica Scripta http://arxiv.org/pdf/1501.03101

49 New Jobs

Postdoctoral Fellow in Star Formation Theory and Computation

The Research School of Astronomy and Astrophysics (RSAA) at the Australian National University (ANU) invites applications for a 3-year postdoctoral fellowship in computational star formation in the newly founded research group of Dr. Christoph Federrath. Dr Federrath’s group is developing novel modelling techniques for star and cluster formation, molecular cloud evolution and turbulent plasmas, with wide-ranging applications to star, planet and galaxy formation and evolution, first stars, galactic interstellar medium, and cosmic structure formation. For this fellowship we are especially looking for excellent early career researchers with expertise and interest in joining our new team. A key element for advancing our understanding of star and galaxy formation is developing 3D hydrodynamical simulations of molecular cloud evolution and star cluster formation. The successful applicant will analyse simulation data and develop their own simulations to compare with submillimetre observations obtained at state-of-the-art national and international facilities, such as ALMA. You will also have the freedom to pursue an independent research program and to collaborate with research partners overseas, in particular with Prof. Ralf Klessen (Heidelberg). You will have access to your own dedicated travel budget. The Research School of Astronomy and Astrophysics has a long history of research and technical activity at the forefront of astronomy and astrophysics. The research interests of our astronomers cover the full length and breadth of the field, from planetary science to cosmology, instrumentation to theory. Our group is embedded in a stimulating and vibrant environment consisting of a large number of senior faculty, postdocs and PhD/Master students working on related topics. RSAA currently has a faculty of 20 permanent scientists, 35 postdocs and 30 PhD students as well as 30 engineers and support staff. Our Distinguished∼ Visitor Program∼ attracts 8 world-class∼ astronomers for long-term∼ visits every year. ANU astronomers have access to world-class supercomputing facilities at ANU as well as observatories such as Keck, Magellan and AAT. Dr Federrath’s group has additional access to international supercomputing facilities and to observational data through established collaborations with internationally recognised submillimetre observers. ANU was recently ranked in the top-10 of all universities worldwide in the field of astronomy and space sciences. The funding for this 3-year fellowship is in place from January 2015 although the starting date is negotiable. The start- ing salary is in the range $70,974–$81,672 p.a., depending on experience, plus employer superannuation contribution of 17%. In order to apply please upload the following documents submitted through http://jobs.anu.edu.au/cw/en/job/492815/postdoctoral-fellow-in-stellar-and-galactic-astrophysics

A current curriculum vitae (CV) • A research plan outlining your proposed research direction for this fellowship • A statement addressing the selection criteria, including a summary of your research achievements • At least three letters of reference sent directly to Christoph Federrath ([email protected]) • Deadline is the 15th February 2015. For more information please contact Dr. Christoph Federrath ([email protected]). Included Benefits:

50 ANU offers a competitive remuneration and benefits package, a friendly and collaborative work environment, generous leave entitlements, flexible working arrangements, a relocation allowance, generous superannuation, salary packaging arrangements including child care, and the potential to support dual-career arrangements. The University actively encourages applications from Aboriginal and Torres Strait Islander people. For more informa- tion on employment opportunities, contact our Indigenous Employment Consultant on [email protected] ANU values diversity and inclusion and believes employment opportunities must not be limited by socio-economic background, race, religion or gender. For more information about staff equity at ANU, visit http://hr.anu.edu.au/staff- equity

Postdoc position in disk dynamics Konkoly Observatory, Budapest, Hungary

The MTA CSFK Lend¨ulet Disk Research Group invites applications for a postdoctoral position in the field of star formation and circumstellar disks. The position is funded through the Hungarian Academy of Sciences’ Postdoctoral Research Program, and applications are to be submitted jointly by the postdoc candidate and the supervisor at the host Institute. For this reason, applicants are requested to first contact Agnes´ K´osp´al (the leader of the Disk Research Group at Konkoly Observatory) by February 18, to discuss the possible research plan. The most important criteria for the fellowship: The candidate must be younger than 35 by September 1, 2015. The date of the candidate’s PhD degree must be within the period January 1, 2010 and February 28, 2015. The position is for two years, from September 2015 to 31 August 2017 (starting date may be postponed by up to four months). The fellowship covers the candidate’s monthly salary for 24 months. The salary corresponds to that of a senior research fellow in the Hungarian civil servant pay grade. Additionally, there is a lump sum for relocation and accommodation expenses. The official call and guide to submitting at the Academy’s webpage: http://mta.hu/data/cikk/13/54/36/cikk_135436/postdoctoral_research_programme_call_2015_EN.pdf http://mta.hu/data/cikk/13/54/36/cikk_135436/Utmutato_2015_-_angol.pdf The MTA CSFK Lend¨ulet (Momentum) Disk Research Group formed in October 2014, with the aim of studying the internal dynamics of circumstellar disks, with special emphasis on using ALMA, the Atacama Large Millime- ter/Submillimeter Array. The group members have several on-going ALMA projects. Our expertise range from embedded YSOs to debris disks, and from optical to millimeter observing techniques to hydrodynamical simulations. You can read more about our group and our research plan at http://konkoly.hu/DRG. Konkoly Observatory is Hungary’s oldest and largest astronomical research institute, located in a newly renovated his- torical building in a beautiful natural reserve area, half hour from the city center (http://www.konkoly.hu/index en.shtml). As part of the larger MTA Research Centre for Astronomy and Earth Sciences, the observatory has been dynamically expanding in recent years, including international staff members. The observatory maintains telescopes at a Hungarian mountain station, and astronomers regularly observe with ESO instrumentation as well through collaborations. Contact: Dr. Agnes´ K´osp´al [email protected]

51 Meetings

Gordon Research Conference on the Origins of Solar Systems

The Gordon Research Conference on the Origins of Solar Systems will be held this year from June 28-July 3, 2015 at Mount Holyoke College in South Hadley, MA. This interdisciplinary meeting is held every two years and is dedicated to bringing together scientists in the fields of meteoritics, astrophysics, planetary science, extrasolar planets, and Earth sciences to discuss frontier research on topics of shared interest. The Gordon Conference is unique in that the main program consists of review talks by 22 invited speakers and 9 discussions leaders who will present their latest research and findings. Significant time is set aside in each session and throughout the week for extended, free-flowing discussion on the materials presented and issues of interest to the audience. In addition, all attendees are invited to present posters on their latest work throughout the week. This years meeting will cover topics including: cosmochemical and astrophysical constraints on the formation of protoplanetary disks; the chemical evolution of protoplanetary disks as revealed by ALMA and meteorites; constraining planet formation through telescopic observations of Solar System objects; and the physical and chemical properties of planetary building blocks and the implications for how the Earth was assembled. The list of speakers and discussion leaders is included below. Applications to attend the meeting can be submitted through the conference website at: http://www.grc.org/programs.aspx?year=2015&program=origins Intentions to contribute a poster can be declared at the same time. Applications will be reviewed and notices of acceptance sent out beginning in late February. Attendance is limited to 200 participants. We expect to be able to dedicate some funds to help support early career scientists. Any questions can be directed to the Chair (Fred Ciesla: [email protected]) or Vice Chair (Ted Bergin: eber- [email protected]). Origins of Solar Systems Topics and Invited Participants: Chair: Fred Ciesla (University of Chicago) Vice Chair: Ted Bergin (University of Michigan) The Formation and Early Evolution of Protoplanetary Disks: Processes and Settings (Lynne Hillenbrand / Martin Bizzarro / Lee Hartmann) The Chemical Evolution of Protoplanetary Disk Materials (Geoffrey Blake / Larry Nittler / Ilaria Pascucci / Ewine Van Dishoeck) Pebbles in Protoplanetary Disks (Andrea Isella / Cornelius Dullemond / Hal Levison) Planet Migration and Its Collateral Effects (Rebekah Dawson / Francesca DeMeo / Richard Nelson / Kevin Walsh) The Nature of Planetesimals and Their Evolution (Adrian Brearley / Julie Castillo-Rogez / Thorsten Kleine) Exoplanetary Systems: A Diversity of Outcomes for Planet Formation (Eliza Kempton / Jayne Birkby / Eric Ford / Nikku Madhusudhan) Debris Disks and Their Connection to Planet Formation (Aki Roberge / Meredith Hughes / Brenda Matthews) The Geophysics and Geochemistry of Planetary Assembly (Stephen Mojzsis / Richard Carlson / Tim Elliott / Sarah Stewart) Outer Solar System Record of Planet Formation (Anita Cochran / David Minton / Scott Sheppard)

52 Exoplanets in Lund 2015

The meeting Exoplanets in Lund 2015 will be held at Lund Observatory 6-8 May 2015 and will cover exoplanet- related science, in particular connected to the CHEOPS satellite mission. A general theme of the meeting is formation, migration and collisions of tightly packed inner planetary systems.

The meeting will start on the morning of Wednesday 6 May and finish on Friday 8 May before lunch, allowing participants to fly back (from Copenhagen Airport) on Friday afternoon.

The programme will have the following sessions:

Exoplanet surveys • Debris discs • Migration and planetary formation • Planetary collisions and dynamics • Planetary structure • Confirmed invited speakers include Clement Baruteau, Tristan Guillot, Zoe Leinhardt, Nikku Madhusudhan, Gi- ampaolo Piotto, Ignasi Ribas, Mark Wyatt.

Registration closes 20 March 2015.

Scientific organising committee: Melvyn B. Davies (SOC chair; Lund University) Willy Benz (University of Bern) Alexis Brandeker (Stockholm University) Anders Johansen (Lund University) Giampaolo Piotto (University of Padoa) Mark Wyatt (University of Cambridge)

Local organising committee: Anders Johansen (LOC chair; Lund University) Bertram Bitsch (Lund University) Alex Mustill (Lund University)

Meeting website: http://www.astro.lu.se/lundexoplanets2015

Contact in case of questions: Anders Johansen ([email protected])

53 31th IAP Colloquium From super-Earths to brown dwarfs: Who’s Who? 29th June - 3rd July 2015, Paris (France)

The proposal of the next colloquium of the Institut d’Astrophysique de Paris devoted to exoplanet science was first considered due to the particular meaning of 2015 which marks the 20th anniversary of the announcement of the first planet, 51 Peg b, around a star other than the Sun. This detection has triggered an extraordinary development in exoplanet research all around the world. Through these twenty years, the remarkable increase of the sample size of identified planets, close nowadays of 2000, has revealed an extreme diversity in mass, density, nature, position, orbit and multiplicity. This diversity has led to try to class the detected objects in diverse types. The colloquium aims to thoroughly examine the definition of planet types, detected by different methods, each of them with its capabilities and its limits, by focusing on the transition from one type to another. Which parameters are controlling these various transitions? It is proposed to analyze from observations and models as well the passage very often ill-defined:

- from Earth-mass planets to super-Earths - from super-Earths to mini-Neptunes - from to super-Jupiters - from super-Jupiters to brown dwarfs - from rocky planets to planets - from bound-planets to free-floating planets

For this purpose, the colloquium will be organized in sessions devoted respectively to the rocky planets, the super- Earths, the giant planets and the brown dwarfs, opened by one or two invited reviews, in which observations and models will be confronted.The opening session will focus on the formation of the Solar System, reviewed at the light of the exoplanet discoveries knowing that these planets are always the point of comparison for the extrasolar systems. Confirmed invited speakers: J´er´emy Leconte (France), Jim Kasting (USA), David Charbonneau (USA ), Masahiro Ikoma (Japan), Natalie Batalha (USA), Adam Showman (USA), Magali Deleuil (France), Gilles Chabrier (France), Kevin Luhman (USA), David Sing (UK) It is already possible to pre-register and to propose a contribution by going for more details to the official website of the 31th IAP Colloquium: http://www.iap.fr/col2015/ Early registration is encouraged, as the number of participants will be limited to approximately 120.

St Andrews Monte Carlo Summer School

A summer school on Monte Carlo radiation transfer techniques will be held at the University of St Andrews, UK from 23rd to 28th August 2015. The course is limited to thirty students, with priority given to STFC-funded PhD students and postdocs. Students will be introduced to the basic techniques in Monte Carlo radiation transfer and their applications to scattered light, dust and gas radiative equilibrium, photoionization, and NLTE molecular line transfer. Several publicly available Monte Carlo codes will be introduced in detail with the goal that by the end of the school the students will have a toolbox of codes that they can use in their own astrophysical research projects. The program will comprise short introductory lectures to each topic, followed by detailed descriptions of individual codes. Lots of time will be set aside for students to become familiar with using the codes and interacting with the lecturers who developed them. Further information, including details of how to register, can be found here: http://www-star.st-and.ac.uk/samcss

54 Habitability in the Universe: From the Early Earth to Exoplanets 2015 March 23 to 27, Porto, Portugal

This conference is the first Conference and WGPP (Working Group and Project Planning) meeting of the TD1308 COST action ORIGINS. The action adresses three basic questions that fascinate and intrigue scientists, and the general public alike: Where, when and how did emerge and evolve on Earth? What are the conditions under which life can exist? Does life exist elsewhere in the Universe and, if it does, how can it be detected and identified? The action has specifically excluded the search for intelligent in its portfolio. The whole conference is divided in 3 parts:

a plenary session on Monday, including a special talk for the 20th anniversary of the discovery of the first • exoplanet (51 Pegasi b), one on the Rosetta mission related to the 67P/Churyumov-Gerasimenko and 15 others invited/contributed talks related to the Working Groups (WG) activities, a special session on Tuesday morning on planetary atmospheres, • 3 Working Group sessions on Tuesday afternoon and Wednesday morning on • – Formation and Evolution of habitable planets, – From inanimate matter to living systems, – Biosignatures and abiotic processes, as well as a discussion on outreach/education in astrobiology. The format of the sessions will consist of invited talks, contributed talks and poster papers. A list of invited speakers and information about the conference is available on the website: http://www.iastro.pt/research/conferences/life-origins2015/ The deadline for registration is 13th February 2015. We look forward to seeing you in Porto! On behalf of the Local Organizing Committee, Jorge Gameiro

Workshop: The Formation of the Solar System II 2 - 4 June 2015 - Berlin / Germany

Although the solar system formed more than 4.5 Gyr ago there still exist a number of indicators to the conditions at the time of its formation. Meteorites, the composition of the and even today s properties of the solar system planets give clues to the solar systems early history. However, there is an ongoing debate on how to interpret these properties. This second workshop The Formation of the Solar System II again has the aim to bring together researchers working in the various fields involved in this quest. It turns out that this is a truly interdisciplinary endeavour, requiring knowledge of super novae explosions, meteorites, , structure and evolution of circumstellar discs, star cluster dynamics, and the early dynamical evolution of planetary systems. Therefore contributions tackling the following subjects are welcome:

Cosmochemical constraints on the physical/chemical conditions in the Solar Nebula • Time scales of the dust and planetesimal growth for the Solar System •

55 Models of the Kuiper belt formation • The role of the stellar environment, with emphasis on star cluster dynamics • Early planetary system development • Future evolution of the Solar System • More information can be found at: https://indico.mpifr-bonn.mpg.de/FormationOfTheSolarSystem2 SOC: Melvyn Davies, Matthieu Gounelle, Pavel Kroupa, Alessandro Morbidelli, Simon Portegies Zwart, Susanne Pfalzner (Chair) Confirmed invited speakers: G¨osta Gahm, Stubbe Hviid, Alessandro Morbidelli Deadline for registration: 28 February 2015

Orion (un)plugged A workshop in two parts: July 1-3 (online), July 6-8, 2015 (unplugged in Vienna, Austria)

While Orion has been known for some time as the nearest birthplace of massive stars, comparably little research has been done on the region as a whole. An unprecedented wealth of data at many different wavelengths is available for this region. In this meeting, we invite the community to discuss the current state of affairs in Orion as well as future prospects. Concept With this meeting, we would like to make use of novel ideas of how to maximize interaction, collaboration, and discussion during a scientific workshop. Our meeting will thus be different from more conventional conferences, and will have two main parts: an online conference (plugged), followed by a physical meeting, styled as an unconference (unplugged) with up to 50 participants. There will be no registration fee. While we encourage participants to attend both parts, it is also possible to attend just one or the other. No previous experience with either conference format is required. Plugged The first part of the meeting, which is meant to set the stage for the second part, will be held online. This easily accessible part is meant to be devoted to information sharing and a first collection of discussion topics for the uncon- ference. With an online conferencing system, we will have participant presentations for a few hours on several days (July 1-3), with time slots that should be convenient at least for Europe and America, like 5-8pm CEST (11am-2pm EDT, 8am-11am PDT). It is also possible to already come to Vienna for this part of the meeting. Unplugged The second part of the workshop (July 6-8) will take place in Vienna. This unconference will be mainly devoted to discussions and collaboration, complemented by poster presentations. The idea is to bring together a group of Orion experts and make the most of this time by maximizing discussion and collaboration to a degree that is not achievable in conventional meetings. In the spirit of an unconference, discussions and activities will largely be organized on the spot, depending on the participants’ interests. Topics Molecular cloud structure, Modes of star formation, YSOs, Clusters vs associations, Stellar populations, Orion in context E-mail contact: jan.forbrich or joao.alves at univie.ac.at https://www.univie.ac.at/alveslab/orion_unplugged/

56 Symposium on The Formation and Destruction of Molecular Clouds 22nd - 23rd June 2015 La Laguna, Tenerife

This two day symposium is part of the European Week of Astronomy and Space Science (EWASS), which will take place at La Laguna, Tenerife Canary Islands, Spain from the 22nd to 26th June, 2015. The goal of this symposium is to investigate the role of molecular clouds in the star formation process, and summarise our knowledge of how they are assembled, form stars, and disperse. Central to this discussion will be the use of observational probes of cloud envelopes (e.g. H, [CI], [CII], [OI], etc) to provide additional constraints on the current theories, and to start to build a new picture of how clouds fit into the larger scales associated with galactic dynamics. We invite abstracts on the following topics * Cloud formation theories * Feedback from young stars as a cloud destruction mechanism * Tracers of cloud envelopes: mass and energy budgets * Star formation rate estimates Important dates * The deadline for abstract submission is 10th March 2015 and details can be found here http://eas.unige.ch/EWASS2015/abstract\protect\unhbox\voidb@x\kern.06em\vbox{\hrulewidth.3em}submission. jsp * The deadline for early registration is 30th April, and details can be found here, http://eas.unige.ch/EWASS2015/registration.jsp Confirmed invited speakers: * James Dale (Ludwig Maximilians University Munich) * Clare Dobbs (University of Exeter) * Min-Young Lee (CEA Saclay) * Suzanne Madden (CEA Saclay) * Julia Roman-Duval (Space Telescope Science Institute) * Jorge Pineda (JPL-CalTech) More details on the symposium can be found at http://eas.unige.ch/EWASS2015/session.jsp?id=S6, and details of the full EWASS programme can be found at http://eas.unige.ch/EWASS2015/index.jsp

57 Summary of Upcoming Meetings

Icy Grain Chemistry for Formation of Complex Organic Molecules: From Molecular Clouds to Protoplanetary Disks, Comets and Meteorites 5 - 7 March 2015 Tokyo Institute of Technology, Japan http://www.geo.titech.ac.jp/lab/nomura/grain_chem/index.html 45th “Saas-Fee Advanced Course”: From Protoplanetary Disks to Planet Formation 15-20 March 2015, Switzerland http://isdc.unige.ch/sf2015 The Soul of Massive Star Formation 15 - 20 March 2015 Puerto Varas, Chile http://www.das.uchile.cl/msf2015/ Star and Planet Formation in the Southwest 23 - 27 March 2015 Oracle, Arizona, USA https://lavinia.as.arizona.edu/~kkratter/SPF1/Home.html Habitability in the Universe: From the Early Earth to Exoplanets 23 - 27 March 2015, Porto, Portugal http://www.iastro.pt/research/conferences/life-origins2015/ Astrophysics from Wide-Field Surveys 30 March - 1 April 2015, London, Burlington House at the RAS, UK http://astro.kent.ac.uk/~df/gp/index.html Cloudy Workshop 4 - 8 May 2015 Warsaw, Poland http://cloud9.pa.uky.edu/~gary/cloudy/CloudySummerSchool/ Exoplanets in Lund 2015 6 - 8 May 2015 Lund, Sweden http://www.astro.lu.se/lundexoplanets2015 Triple Evolution & Dynamics in Stellar and Planetary Systems 31 May - 5 June 2015 Haifa, Israel http://trendy-triple.weebly.com Workshop on the Formation of the Solar System II 2 - 4 June 2015 Berlin, Germany https://indico.mpifr-bonn.mpg/FormationOfTheSolarSystem2 IGM@50: is the Intergalactic medium driving Star Formation? 8 - 12 June 2015 Abbazia di Spineto, Italy http://www.arcetri.astro.it/igm50 The Formation and Destruction of Molecular Clouds 22 - 23 June 2015 Tenerife, Spain http://eas.unige.ch/EWASS2015/session.jsp?id=S6 30 Years of Photodissociation regions - A Symposium to honor David Hollenbach’s lifetime in science 28 June - 3 July 2015 http://pdr30.strw.leidenuniv.nl

58 Gordon Research Conference on Origins of Solar Systems 28 June - 3 July 2015 http://www.grc.org/programs.aspx?id=12345 Disc dynamics and planet formation 29 June - 3 July 2015 Larnaka, Cyprus http://www.star.uclan.ac.uk/discs2015 The Stellar IMF at Low Masses: A Critical Look at Variations and Environmental Dependencies 29 June - 1 July 2015 Baltimore, Maryland, USA http://www.stsci.edu/institute/conference/stellar-imf/ From super-Earths to brown dwarfs: Who’s who 29 June - 3 July 2015 Paris, France http://www.iap.fr/col2015 Orion (un)plugged 1-3 + 6-8 July 2015 Vienna, Austria https://www.univie.ac.at/alveslab/orion_unplugged/ From Interstellar Clouds to Star-forming Galaxies: Universal Processes? 3 - 7 August 2015 http://astronomy2015.org/symposium_315 17 - 21 August 2015 Tokyo, Japan https://www.cps-jp.org/~dust/ Extreme Solar Systems III 29 November - 4 December 2015 Hawaii, USA http://ciera.northwestern.edu/Hawaii2015.php The 19th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun 6 - 10 June 2016 Uppsala, Sweden http://www.coolstars19.com Other meetings: http://www1.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/meetings/

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