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
Artikel i vetenskaplig tidskrift, 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


Star formation


John J. Tobin

National Radio Astronomy Observatory

S. Thomas Megeath

University of Toledo

Merel van't Hoff

Universiteit Leiden

Ana Karla Diaz-Rodriguez

Instituto de Astrofisica de Andalucía (IAA)

Nickalas Reynolds

University of Oklahoma

Mayra Osorio

Consejo Superior de Investigaciones Científicas (CSIC)

Guillem Anglada

Consejo Superior de Investigaciones Científicas (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

Universidad de Concepción


William J. Fischer

Space Telescope Science Institute (STScI)

Mihkel Kama

University of Cambridge

Magnus V. Persson

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

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

Universiteit Leiden

Lisa Patel

University of Oklahoma

Laura Perez

Universidad de Chile (UCH)

Dominique Segura-Cox


Rajeeb Sharma

University of Oklahoma

Lukasz Tychoniec

Universiteit Leiden

Friedrich Wyrowski


Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 886 1 6


Meteorologi och atmosfärforskning

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik



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