THE STAR FORMATION NEWSLETTER An electronic publication dedicated to early stellar/planetary evolution and molecular clouds No. 274 — 15 October 2015 Editor: Bo Reipurth ([email protected]) List of Contents The Star Formation Newsletter Interview ...................................... 3 Perspective .................................... 6 Editor: Bo Reipurth [email protected] Abstracts of Newly Accepted Papers .......... 11 Technical Editor: Eli Bressert Abstracts of Newly Accepted Major Reviews . 47 [email protected] Dissertation Abstracts ........................ 48 Technical Assistant: Hsi-Wei Yen New Jobs ..................................... 49 [email protected] Meetings ..................................... 52 Editorial Board Summary of Upcoming Meetings ............. 53 Short Announcements ........................ 54 Joao Alves Alan Boss Jerome Bouvier Lee Hartmann Thomas Henning Paul Ho Cover Picture Jes Jorgensen Charles J. Lada The HH 24 jet complex emanates from a dense Thijs Kouwenhoven cloud core in the L1630 cloud in Orion which hosts a Michael R. Meyer small multiple protostellar system known as SSV63. Ralph Pudritz The nebulous star to the south is the visible T Tauri Luis Felipe Rodr´ıguez star SSV59. Color image obtained based on the Ewine van Dishoeck following filters with composite image color assign- Hans Zinnecker ments in parenthesis: g (blue), r (cyan), I (orange), Hα (red), [S II] (blue). The images were obtained The Star Formation Newsletter is a vehicle for with GMOS on Gemini North in 0.5 arcsecond see- fast distribution of information of interest for as- ing. The field of view is 4.2x5 arcminutes, and the tronomers working on star and planet formation orientation is north up, east left. and molecular clouds. You can submit material Images by Bo Reipurth and Colin Aspin. for the following sections: Abstracts of recently Color mosaic by Travis Rector. 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- ings broadly of interest to the star and planet for- mation and early solar system community), New Submitting your abstracts Jobs (advertising jobs specifically aimed towards persons within the areas of the Newsletter), and Latex macros for submitting abstracts Short Announcements (where you can inform or re- and dissertation abstracts (by e-mail to quest information from the community). Addition- [email protected]) are appended to ally, the Newsletter brings short overview articles each Call for Abstracts. You can also on objects of special interest, physical processes or submit via the Newsletter web inter- theoretical results, the early solar system, as well face at http://www2.ifa.hawaii.edu/star- as occasional interviews. formation/index.cfm Newsletter Archive www.ifa.hawaii.edu/users/reipurth/newsletter.htm entails for a career in the absence of a long-term funding perspective, but it somehow worked, and diffusing into Manuel G¨udel other research areas has become an important constant in in conversation with Bo Reipurth my career ever since – I never regretted it! I joined Jeff Linsky’s group at JILA, University of Colorado in Boul- der, an exciting environment to put my plan into action. I worked on linking coronal particle acceleration (traced by radio emission) with coronal heating (traced by X-rays). Those years, the early-to-mid nineties, were a golden age of X-ray astronomy with new space observatories launched almost every other year (ROSAT, EUVE, ASCA, Bep- poSAX and others). It gave me the opportunity to move into X-ray astronomy and stellar coronal research. We dis- covered what I thought was to be expected from solar flare physics, namely a linear correlation between the radio and X-ray luminosities of active stellar coronae. Arnold Benz and I interpreted this finding quantitatively as evidence for continuous heating by particle beams accelerated like in solar flares. The correlation was good enough to pre- dict radio fluxes from X-rays from very hot (>10 million degrees) coronal plasma. Thus came our first radio dis- Q: What was your thesis about, and who was your adviser? coveries of young Suns (first EK Draconis, the star that A: It all happened somewhat by chance. After my under- has guided my career to the present day), rather precisely graduate studies in theoretical physics at ETH Zurich, I at the predicted flux level. The correlation is by no means was torn between pursuing a PhD in theory (I was much universal – it applies only to very hot coronae of active attracted – and still am! – by fundamental physics like stars (and fails miserably for our Sun!). This point was quantum field theory that blossomed at ETH) or rather unfortunately often ignored and led to some misunder- getting back to my deep interest since my childhood, name- standings. In any case, we left it there, and if it was of ly astronomy. Luckily (I would guess) I followed the calling any interest at all, it was referred to as the ”radio–X-ray of my heart and decided in favor of astronomy. I was fortu- luminosity correlation”. About a decade later, the newly nate that Arnold Benz offered me a PhD position at ETH discovered radio and X-ray emitting brown dwarfs were to work in plasma astrophysics and on the solar corona. found to severely violate our correlation; ironically, this That was the best of all worlds for me – concepts of mag- was the moment when colleagues started referring to the netic fields in plasmas and radiation propagation pleased ”G¨udel-Benz relation”. Obviously, the interest in different my theoretical streak. I worked on the interpretation of physics was awakened. the shortest, millisecond solar radio bursts resulting from The rich harvest from the X-ray satellites was also ideal to unstable coronal particle distributions. I had enough time study stellar activity evolution. By sheer luck, I met Ed to also spread out into other fields, like the theory of soli- Guinan in a half-empty lecture hall of a solar conference ton propagation in a multi-fluid plasma, numerical parti- a seat row in front of me; we were both silently working cle simulations (with a few thousand particles to follow - on papers about EK Dra - without knowing of each other! a good standard at the time!), and observations with the A chat in the coffee break started our joint studies of the VLA and other big radio dishes to look for solar analo- ”Sun in Time”, including X-rays; planetary atmospheric gies in the radio emission of low-mass stars. My generous physicists later used this work to study planet evolution mentor thus paved the way for my future career. – especially people in Austria where, in a funny turn of Q: Your observational work started at radio continuum events one and a half decades later, I found my new home. wavelengths, but you soon switched to X-ray studies of stel- Q: Why did you turn your attention to star formation? lar coronae. What motivated this change? I was lucky to obtain a tenure-track position in Switzer- A: Solar radio astronomy offered, and still offers, exciting land after my third postdoc year abroad and requested research and physical insight but it takes place in a rela- tenure after another two years. Now I could diffuse eas- tively small and somewhat isolated community. I wanted ily into new fields with less career risk; I engaged myself to apply solar concepts to the bigger world of stars and in- in large space projects for which our institute developed vested my first one-year postdoc grant to give up on solar instrumentation. I became a science Co-I of the XMM- physics and move into stellar radio astronomy. I was ob- Newton Reflection Grating Spectrometer (RGS) and took viously not aware of the risk such a full-blown turnaround 3 the position of the Swiss Co-Principal Investigator of MIRI In my own Chandra campaign on protostellar X-ray jets, on JWST (which I’m keeping at ETH Zurich in parallel among them DG Tau B, we found strongly absorbed stellar to my new job in Vienna). With Spitzer and Herschel on X-rays but no jets. I was vaguely aware of the CTTS DG the horizon, my fascination for young stars, and the many Tau nearly an arcminute north of DG Tau B but initially new X-ray findings in star formation, I got interested in didn’t pay attention. But there was this fuzzy cloud of a studying the influence of high-energy, ionizing radiation few excess X-ray counts around it. It turned out to be the on stellar environments, specifically protoplanetary disks, trace of a luminous X-ray jet. The most fascinating feature which led to fruitful new projects and collaborations. I am was DG Tau’s X-ray spectrum – composed of two entirely confident that JWST will push this field much further. independent components which we now know to be a soft Q: T Tauri stars (TTS) are often X-ray emitters. What component from the jet very close to the star (20-30 AU is the basic mechanism? and closer) and a highly absorbed component from a very hot, flaring corona. The absorption lacks the expected, A: TTS X-rays were discovered in the early days of X-ray accompanying dust extinction; our model for these ”Two astronomy. They are akin to X-rays from other young, Absorber X-ray” (TAX) sources posits that absorption is active stars and so are thought to be coronal. Strong due to dust-depleted gas streams close to the star, most magnetic fields abound on T Tauri stars, after all. There likely the accretion streams but maybe also disk winds. are some interesting, distinctive properties of classical T Tauris (CTTS), however.