312 — 13 December 2018 Editor: Bo Reipurth ([email protected]) List of Contents
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THE STAR FORMATION NEWSLETTER An electronic publication dedicated to early stellar/planetary evolution and molecular clouds No. 312 — 13 December 2018 Editor: Bo Reipurth ([email protected]) List of Contents The Star Formation Newsletter Abstracts of Newly Accepted Papers ........... 3 Abstracts of Newly Accepted Major Reviews . 37 Editor: Bo Reipurth [email protected] Dissertation Abstracts ........................ 38 Associate Editor: Anna McLeod New Jobs ..................................... 41 [email protected] Meetings ..................................... 44 Technical Editor: Hsi-Wei Yen Summary of Upcoming Meetings ............. 45 [email protected] Editorial Board Joao Alves Alan Boss Cover Picture Jerome Bouvier Lee Hartmann NGC 2175 is a 1-2 Myr old cluster in Gemini at a Thomas Henning distance of roughly 2 kpc. It is dominated by the Paul Ho O6.5V star HD 42088, which ionizes the surround- Jes Jorgensen ing HII region, also known as NGC 2175, but more Charles J. Lada commonly as Sh2-252. The western side of the HII Thijs Kouwenhoven region is bounded by molecular clouds, which are Michael R. Meyer sculpted by the UV radiation and the expansion of Ralph Pudritz the HII region, as seen in this HST image. Luis Felipe Rodr´ıguez Ewine van Dishoeck Courtesy ESA/Hubble & NASA Hans Zinnecker The Star Formation Newsletter is a vehicle for fast distribution of information of interest for as- tronomers working on star and planet formation and molecular clouds. You can submit material Submitting your abstracts for the following sections: Abstracts of recently accepted papers (only for papers sent to refereed Latex macros for submitting abstracts journals), Abstracts of recently accepted major re- and dissertation abstracts (by e-mail to views (not standard conference contributions), Dis- [email protected]) are appended to sertation Abstracts (presenting abstracts of new each Call for Abstracts. You can also Ph.D dissertations), Meetings (announcing meet- submit via the Newsletter web inter- ings broadly of interest to the star and planet for- face at http://www2.ifa.hawaii.edu/star- mation and early solar system community), New formation/index.cfm Jobs (advertising jobs specifically aimed towards persons within the areas of the Newsletter), and Short Announcements (where you can inform or re- quest information from the community). Addition- ally, the Newsletter brings short overview articles on objects of special interest, physical processes or theoretical results, the early solar system, as well as occasional interviews. Newsletter Archive www.ifa.hawaii.edu/users/reipurth/newsletter.htm Abstracts of recently accepted papers Inner disk structure of the classical T Tauri star LkCa 15 S.H.P. Alencar1,2, J. Bouvier2, J.-F. Donati3, E. Alecian2, C.P. Folsom3, K. Grankin4, G.A.J. Hussain5, C. Hill3, A.-M. Cody6, A. Carmona3, C. Dougados2, S.G. Gregory7, G. Herczeg8, F. M´enard2, C. Moutou9, L. Malo9 and M. Takami10 1 Departamento de Fisica ICEx UFMG, Av. Antˆonio Carlos 6627, 30270-901 Belo Horizonte, MG, Brazil; 2 Universit´e Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France; 3 IRAP, Universit´ede Toulouse, CNRS, UPS, CNES, 14 Avenue Edouard Belin, Toulouse, F-31400, France; 4 Crimean Astrophysical Observatory, Scientific Research Institute, 298409, Nauchny, Crimea; 5 ESO, Karl-Schwarzschild-Str. 2, D-85748 Garching, Germany; 6 NASA Ames Research Center, Moffett Field, CA 94035, USA; 7 SUPA, School of Physics and Astronomy, Univ. of St Andrews, St Andrews, Scotland KY16 9SS, UK; 8 Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, Beijing 100871, China; 9 CFHT Corporation, 651238 Mamalahoa Hwy, Kamuela, Hawaii 96743, USA; 10 Institute of Astronomy and Astrophysics, Academia Sinica, PO Box 23141, 106, Taipei, Taiwan E-mail contact: silvia at fisica.ufmg.br Magnetospheric accretion has been thoroughly studied in young stellar systems with full non-evolved accretion disks, but it is poorly documented for transition disk objects with large inner cavities. We aim at characterizing the star- disk interaction and the accretion process onto the central star of LkCa 15, a prototypical transition disk system with an inner dust cavity that is 50 au wide. We obtained quasi-simultaneous photometric and spectropolarimetric observations of the system over several rotational periods. We analyzed the system light curve and associated color variations, as well as changes in spectral continuum and line profile to derive the properties of the accretion flow from the edge of the inner disk to the central star. We also derived magnetic field measurements at the stellar surface. We find that the system exhibits magnetic, photometric, and spectroscopic variability with a period of about 5.70 days. The light curve reveals a periodic dip, which suggests the presence of an inner disk warp that is located at the corotation radius at about 0.06 au from the star. Line profile variations and veiling variability are consistent with a magnetospheric accretion model where the funnel flows reach the star at high latitudes. This leads to the development of an accretion shock close to the magnetic poles. All diagnostics point to a highly inclined inner disk that interacts with the stellar magnetosphere. The spectroscopic and photometric variability on a timescale of days to weeks of LkCa 15 is remarkably similar to that of AA Tau, the prototype of periodic dippers. We therefore suggest that the origin of the variability is a rotating disk warp that is located at the inner edge of a highly inclined disk close to the star. This contrasts with the moderate inclination of the outer transition disk seen on the large scale and thus provides evidence for a significant misalignment between the inner and outer disks of this planet-forming transition disk system. Accepted by Astronomy & Astrophysics http://arxiv.org/pdf/1811.04806 The Formation of Supermassive Black Holes from Population III.1 Seeds. I. Cosmic Formation Histories and Clustering Properties Nilanjan Banik1, Jonathan C. Tan2 and Pierluigi Monaco3 1 Univ. of Amsterdam and Leiden Univ.; 2 Chalmers Univ. and Univ. of Virginia; 3 INAF–Osservatorio Astronomico di Trieste E-mail contact: jctan.astro at gmail.com We calculate cosmic distributions in space and time of the formation sites of the first, “Pop III.1” stars, exploring a model in which these are the progenitors of all supermassive black holes (SMBHs), seen in the centers of most large galaxies. Pop III.1 stars are defined to form from primordial composition gas in dark matter minihalos with 6 ∼ 10 M⊙ that are isolated from neighboring astrophysical sources by a given isolation distance, diso. We assume Pop 3 III.1 sources are seeds of SMBHs, based on protostellar support by dark matter annihilation heating that allows them 5 to accrete a large fraction of their minihalo gas, i.e., ∼ 10 M⊙. Exploring diso from 10–100 kpc (proper distances), we predict the redshift evolution of Pop III.1 source and SMBH remnant number densities. The local, z = 0 density 3 of SMBHs constrains diso ∼< 100 kpc (i.e., 3 Mpc comoving distance at z ≃ 30). In our simulated (∼ 60 Mpc) comoving volume, Pop III.1 stars start forming just after z = 40. Their formation is largely complete by z ≃ 25 to 20 for diso = 100 to 50 kpc. We follow source evolution to z = 10, by which point most SMBHs reside in halos with > 8 ∼10 M⊙. Over this period, there is relatively limited merging of SMBHs for these values of diso. We also predict SMBH clustering properties at z = 10: feedback suppression of neighboring sources leads to relatively flat angular correlation functions. Accepted by MNRAS https://arxiv.org/pdf/1608.04421 Kinematic links and the co-evolution of MHD winds, jets, and inner disks from a high- resolution optical [OI] survey Andrea Banzatti1,2, Ilaria Pascucci1,2,3, Suzan Edwards4, Min Fang5,2, Uma Gorti6 and Mario Flock3 1 Department of Planetary Sciences, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721, USA; 2 Earths in Other Solar Systems Team, NASA Nexus for Exoplanet System Science; 3 Max Planck Institute for Astronomy (MPIA), K¨onigsthul 17, 69117, Heidelberg, Germany; 4 Five College Astronomy Department, Smith College, Northampton, MA 01063, USA; 5 Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA; 6 SETI Institute/NASA Ames Research Center, Mail Stop 245-3, Moffett Field, CA 94035-1000, USA E-mail contact: banzatti at lpl.arizona.edu We present a survey of optical [OI] emission at 6300 A˚ toward 65 TTauri stars at the spectral resolution of ∼ 7 km/s. Past work identified a highly blueshifted velocity component (HVC) tracing microjets, and a less blueshifted low-velocity-component (LVC) attributed to winds. We focus here on the LVC kinematics to investigate links between winds, jets, accretion, and disk dispersal. We track the behavior of four types of LVC components: a broad and narrow component (“BC” and “NC”) in LVCs that are decomposed into two Gaussians, which typically have an HVC, and the single-Gaussian LVC profiles separated into those that have an HVC (“SCJ”) and those that do not (“SC”). LVC centroid velocities and line widths correlate with HVC equivalent width and accretion luminosity, suggesting that LVC/winds and HVC/jets are kinematically linked and connected to accretion. The deprojected HVC velocity correlates with accretion luminosity, showing that faster jets come with higher accretion. BC and NC kinematics correlate and their blueshifts are maximum at ∼ 35◦, suggesting a conical wind geometry with this semi-opening angle. Only SCs include n13−31 up to ∼ 3 and their properties correlate with this infrared index, showing that [OI] emission recedes to larger radii as the inner dust is depleted, tracing less dense/hot gas and a decrease in wind velocity. All together, these findings support a scenario where optically thick, accreting inner disks launch radially-extended MHD disk winds that feed jets, and where inner disk winds recede to larger radii and jets disappear in concert with dust depletion.