Constraining the Infalling Envelope Models of Embedded Protostars: BHR 71 and Its Hot Corino
Journal article, 2020
The collapse of a protostellar envelope results in the growth of a protostar and the development of a protoplanetary disk, playing a critical role during the early stages of star formation. Characterizing the gas infall in the envelope constrains the dynamical models of star formation. We present unambiguous signatures of infall, probed by optically thick molecular lines, toward an isolated embedded protostar, BHR 71 IRS1. The three-dimensional radiative transfer calculations indicate that a slowly rotating infalling envelope model following the "inside-out" collapse reproduces the observations of both lines, as well as the low-velocity emission of the HCN line. The envelope has a model-derived ag lines, where outflows or a Keplerian disk may contribute. The ALMA observations serendipitously discover the emission of complex organic molecules (COMs) concentrated within a radius of 100 au, indicating that BHR 71 IRS1 harbors a hot corino. Eight species of COMs are identified, including CH3OH and CH3OCHO, along with H2CS, SO2 and HCN v(2) = 1. The emission of methyl formate and C-13-methanol shows a clear velocity gradient within a radius of 50 au, hinting at an unresolved Keplerian rotating disk.
Astrochemistry
Gravitational collapse
Bok globules
Protostars
Radiative transfer
Star formation
Author
Yao-Lun Yang
RIKEN
University of Texas
Evans
University of Texas
Kyung Hee University
Korea Astronomy and Space Science Institute
Aaron Smith
Massachusetts Institute of Technology (MIT)
Jeong-Eun Lee
Kyung Hee University
John J. Tobin
University of Oklahoma
National Radio Astronomy Observatory
Susan Terebey
California State University
Hannah Calcutt
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Jes K. Jorgensen
University of Copenhagen
Joel D. Green
Space Telescope Science Institute (STScI)
University of Texas
Tyler L. Bourke
SKA Organisation
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 891 1 61Subject Categories (SSIF 2011)
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.3847/1538-4357/ab7201