The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. I. Identifying and Characterizing the Protostellar Content of the OMC-2 FIR4 and OMC-2 FIR3 Regions
Journal article, 2019
We present Atacama Large Millimeter/submillimeter Array (0.87 mm) and Very Large Array (9 mm) observations toward OMC-2 FIR4 and OMC-2 FIR3 within the Orion integral-shaped filament, thought to be two of the nearest regions of intermediate-mass star formation. We characterize the continuum sources within these regions on ?40 au (01) scales and associated molecular line emission at a factor of ?30 better resolution than previous observations at similar wavelengths. We identify six compact continuum sources within OMC-2 FIR4, four in OMC-2 FIR3, and one additional source just outside OMC-2 FIR4. This continuum emission is tracing the inner envelope and/or disk emission on less than 100 au scales. HOPS-108 is the only protostar in OMC-2 FIR4 that exhibits emission from high-excitation transitions of complex organic molecules (e.g., methanol and other lines) coincident with the continuum emission. HOPS-370 in OMC-2 FIR3, with L;?;360 L, also exhibits emission from high-excitation methanol and other lines. The methanol emission toward these two protostars is indicative of temperatures high enough to thermally evaporate it from icy dust grains; overall, these protostars have characteristics similar to hot corinos. We do not identify a clear outflow from HOPS-108 in (CO)-C-12, but we find evidence of interaction between the outflow/jet from HOPS-370 and the OMC-2 FIR4 region. A multitude of observational constraints indicate that HOPS-108 is likely a low- to intermediate-mass protostar in its main mass accretion phase and is the most luminous protostar in OMC-2 FIR4. The high-resolution data presented here are essential for disentangling the embedded protostars from their surrounding dusty environments and characterizing them.
Star-forming regions
Radio interferometry
Interstellar medium
Young stellar objects
Protostars
Star formation
Author
John J. Tobin
National Radio Astronomy Observatory
S. Thomas Megeath
University of Toledo
Merel van't Hoff
Leiden University
Ana Karla Diaz-Rodriguez
Institute of Astrophysics of Andalusia (IAA)
Nickalas Reynolds
University of Oklahoma
Mayra Osorio
Spanish National Research Council (CSIC)
Guillem Anglada
Spanish National Research Council (CSIC)
Elise Furlan
California Institute of Technology (Caltech)
Nicole Karnath
University of Toledo
Stella S. R. Offner
The University of Texas at Austin
Patrick D. Sheehan
National Radio Astronomy Observatory
Sarah I. Sadavoy
Harvard-Smithsonian Center for Astrophysics
Amelia M. Stutz
University of Concepcion
Max Planck Society
William J. Fischer
Space Telescope Science Institute (STScI)
Mihkel Kama
University of Cambridge
Magnus V. Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
James Di Francesco
National Research Council Canada
Leslie W. Looney
University of Illinois
Dan M. Watson
University of Rochester
Zhi-Yun Li
University of Virginia
Ian Stephens
Harvard-Smithsonian Center for Astrophysics
Claire J. Chandler
National Radio Astronomy Observatory
Erin Cox
Northwestern University
Michael M. Dunham
Harvard-Smithsonian Center for Astrophysics
SUNY Fredonia
Kaitlin Kratter
University of Arizona
Marina Kounkel
Western Washington University
Brian Mazur
University of Toledo
Nadia M. Murillo
Leiden University
Lisa Patel
University of Oklahoma
Laura Perez
University of Chile (UCH)
Dominique Segura-Cox
Max Planck Society
Rajeeb Sharma
University of Oklahoma
Lukasz Tychoniec
Leiden University
Friedrich Wyrowski
Max Planck Society
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 886 1 6Subject Categories
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.3847/1538-4357/ab498f