Dynamical structure of the inner 100 AU of the deeply embedded protostar IRAS 16293–2422

Journal Article · Sun Jul 20 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/790/1/55· OSTI ID:22365563

Favre, Cécile; Field, David ^[1]; Jørgensen, Jes K.; Brinch, Christian; Bisschop, Suzanne E. ^[2]; Bourke, Tyler L. ^[3]; Hogerheijde, Michiel R. ^[4]; Frieswijk, Wilfred W. F., ^[5]

---

1. Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
2. Centre for Star and Planet Formation, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark)
3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS42, Cambridge, MA 02138 (United States)
4. Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands)
5. Netherlands Institute for Radio Astronomy, Postbus 2, 7990-AA Dwingeloo (Netherlands)

A fundamental question about the early evolution of low-mass protostars is when circumstellar disks may form. High angular resolution observations of molecular transitions in the (sub)millimeter wavelength windows make it possible to investigate the kinematics of the gas around newly formed stars, for example, to identify the presence of rotation and infall. IRAS 16293–2422 was observed with the extended Submillimeter Array (eSMA) resulting in subarcsecond resolution (0.''46 × 0.''29, i.e., ∼55 × 35 AU) images of compact emission from the C{sup 17}O (3-2) and C{sup 34}S (7-6) transitions at 337 GHz (0.89 mm). To recover the more extended emission we have combined the eSMA data with SMA observations of the same molecules. The emission of C{sup 17}O (3-2) and C{sup 34}S (7-6) both show a velocity gradient oriented along a northeast-southwest direction with respect to the continuum marking the location of one of the components of the binary, IRAS 16293A. Our combined eSMA and SMA observations show that the velocity field on the 50-400 AU scales is consistent with a rotating structure. It cannot be explained by simple Keplerian rotation around a single point mass but rather needs to take into account the enclosed envelope mass at the radii where the observed lines are excited. We suggest that IRAS 16293–2422 could be among the best candidates to observe a pseudo-disk with future high angular resolution observations.

• OSTI ID: 22365563
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 790; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CARBON MONOXIDE
CARBON SULFIDES
EMISSION
EVOLUTION
MASS
MOLECULES
PROTOSTARS
RESOLUTION
ROTATION
STARS
VELOCITY
WAVELENGTHS