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

DOI: 
10.3847/1538-4357/ab498f
Publication date: 
01/11/2019
Main author: 
Tobin, John J.
IAA authors: 
Díaz-Rodríguez, Ana Karla;Osorio, Mayra;Anglada, Guillem
Authors: 
Tobin, John J.;Megeath, S. Thomas;van’t Hoff, Merel;Díaz-Rodríguez, Ana Karla;Reynolds, Nickalas;Osorio, Mayra;Anglada, Guillem;Furlan, Elise;Karnath, Nicole;Offner, Stella S. R.;Sheehan, Patrick D.;Sadavoy, Sarah I.;Stutz, Amelia M.;Fischer, William J.;Kama, Mihkel;Persson, Magnus;Di Francesco, James;Looney, Leslie W.;Watson, Dan M.;Li, Zhi-Yun;Stephens, Ian;Chandler, Claire J.;Cox, Erin;Dunham, Michael M.;Kratter, Kaitlin;Kounkel, Marina;Mazur, Brian;Murillo, Nadia M.;Patel, Lisa;Perez, Laura;Segura-Cox, Dominique;Sharma, Rajeeb;Tychoniec, Łukasz;Wyrowski, Friedrich
Journal: 
The Astrophysical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
886
Pages: 
6
Abstract: 
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 (0.″1) 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 <SUB>☉</SUB>, 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 <SUP>12</SUP>CO, 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.
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077332268&doi=10.3847%2f1538-4357%2fab498f&partnerID=40&md5=66f1fe692d966425f158e93a7ca2eede
ADS Bibcode: 
2019ApJ...886....6T
Keywords: 
Interstellar medium;Protostars;Radio interferometry;Star formation;Star-forming regions;Young stellar objects