TY - JOUR
T1 - The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. V. A Characterization of Protostellar Multiplicity
AU - Tobin, John J.
AU - Offner, Stella S.R.
AU - Kratter, Kaitlin M.
AU - Megeath, S. Thomas
AU - Sheehan, Patrick D.
AU - Looney, Leslie W.
AU - Diaz-Rodriguez, Ana Karla
AU - Osorio, Mayra
AU - Anglada, Guillem
AU - Sadavoy, Sarah I.
AU - Furlan, Elise
AU - Segura-Cox, Dominique
AU - Karnath, Nicole
AU - Van 'T Hoff, Merel L.R.
AU - Van Dishoeck, Ewine F.
AU - Li, Zhi Yun
AU - Sharma, Rajeeb
AU - Stutz, Amelia M.
AU - Tychoniec, Łukasz
N1 - Funding Information:
The authors thank the anonymous referee for a constructive report that helped improve the quality of the manuscript. J.J.T. acknowledges support from NSF AST-1814762 and HST-GO-15141.018-A. S.S.R.O. acknowledges support from NSF Career grant 1748571. L.W.L. acknowledges support from NSF AST-1910364. G.A. and M.O. acknowledge support from the Spanish MINECO/AEI AYA2017-84390-C2-1-R (co-funded by FEDER) and PID2020-114461GB-I00/AEI/10.13039/501100011033 grants, and from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). Z.Y.L. is supported in part by NASA NSSC18K1095 and NSF 1815784. A.S. gratefully acknowledges funding support through Fondecyt Regular (project code 1180350) and from the Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA) BASAL grant AFB-170002. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.00041.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The PI acknowledges assistance from Allegro, the European ALMA Regional Center node in the Netherlands. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This research made use of APLpy, an open-source plotting package for Python hosted at http://aplpy.github.com . This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration, 2013) http://www.astropy.org .
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/1/1
Y1 - 2022/1/1
N2 - We characterize protostellar multiplicity in 20 Current address: Niels Bohr Institute, University of Copenhagen, Øster Voldgade 5a7, DK-1350, Copenhagen K, Denmark. the Orion molecular clouds using Atacama Large Millimeter/submillimeter Array 0.87 mm and Very Large Array 9 mm continuum surveys toward 328 protostars. These observations are sensitive to projected spatial separations as small as ∼20 au, and we consider source separations up to 104 au as potential companions. The overall multiplicity fraction (MF) and companion fraction (CF) for the Orion protostars are 0.30 ± 0.03 and 0.44 ± 0.03, respectively, considering separations from 20 to 104 au. The MFs and CFs are corrected for potential contamination by unassociated young stars using a probabilistic scheme based on the surface density of young stars around each protostar. The companion separation distribution as a whole is double peaked and inconsistent with the separation distribution of solar-type field stars, while the separation distribution of Flat Spectrum protostars is consistent solar-type field stars. The multiplicity statistics and companion separation distributions of the Perseus star-forming region are consistent with those of Orion. Based on the observed peaks in the Class 0 separations at ∼100 au and ∼103 au, we argue that multiples with separations <500 au are likely produced by both disk fragmentation and turbulent fragmentation with migration, and those at ?3103 au result primarily from turbulent fragmentation. We also find that MFs/CFs may rise from Class 0 to Flat Spectrum protostars between 100 and 103 au in regions of high young stellar object density. This finding may be evidence for the migration of companions from >103 au to <103 au, and that some companions between 103 and 104 au must be (or become) unbound.
AB - We characterize protostellar multiplicity in 20 Current address: Niels Bohr Institute, University of Copenhagen, Øster Voldgade 5a7, DK-1350, Copenhagen K, Denmark. the Orion molecular clouds using Atacama Large Millimeter/submillimeter Array 0.87 mm and Very Large Array 9 mm continuum surveys toward 328 protostars. These observations are sensitive to projected spatial separations as small as ∼20 au, and we consider source separations up to 104 au as potential companions. The overall multiplicity fraction (MF) and companion fraction (CF) for the Orion protostars are 0.30 ± 0.03 and 0.44 ± 0.03, respectively, considering separations from 20 to 104 au. The MFs and CFs are corrected for potential contamination by unassociated young stars using a probabilistic scheme based on the surface density of young stars around each protostar. The companion separation distribution as a whole is double peaked and inconsistent with the separation distribution of solar-type field stars, while the separation distribution of Flat Spectrum protostars is consistent solar-type field stars. The multiplicity statistics and companion separation distributions of the Perseus star-forming region are consistent with those of Orion. Based on the observed peaks in the Class 0 separations at ∼100 au and ∼103 au, we argue that multiples with separations <500 au are likely produced by both disk fragmentation and turbulent fragmentation with migration, and those at ?3103 au result primarily from turbulent fragmentation. We also find that MFs/CFs may rise from Class 0 to Flat Spectrum protostars between 100 and 103 au in regions of high young stellar object density. This finding may be evidence for the migration of companions from >103 au to <103 au, and that some companions between 103 and 104 au must be (or become) unbound.
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U2 - 10.3847/1538-4357/ac36d2
DO - 10.3847/1538-4357/ac36d2
M3 - Article
AN - SCOPUS:85125849549
SN - 0004-637X
VL - 925
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 39
ER -