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

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 RegionsTobin, John J.Megeath, S. Thomasvan't Hoff, MerelDíaz-Rodríguez, Ana KarlaReynolds, NickalasOsorio, MayraAnglada, GuillemFurlan, EliseKarnath, NicoleOffner, Stella S. R.Sheehan, Patrick D.Sadavoy, Sarah I.Stutz, Amelia M.Fischer, William J.Kama, MihkelPersson, Magnusdi Francesco, JamesLooney, Leslie W.Watson, Dan M.Li, Zhi-YunStephens, IanChandler, Claire J.Cox, ErinDunham, Michael M.Kratter, KaitlinKounkel, MarinaMazur, BrianMurillo, Nadia M.Patel, LisaPerez, LauraSegura-Cox, DominiqueSharma, RajeebTychoniec, ŁukaszWyrowski, FriedrichDOI: info:10.3847/1538-4357/ab498fv. 8866
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 et al. 2019. "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." The Astrophysical Journal 886:6. https://doi.org/10.3847/1538-4357/ab498f
ID: 154585
Type: article
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
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 , 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 12CO, 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.