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.

Star formation

Bok globules

Gravitational collapse

Radiative transfer




Yao-Lun Yang

The University of Texas at Austin



Kyung Hee University

Korea Astronomy and Space Science Institute

The University of Texas at Austin

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

The California State University

Hannah Calcutt

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

Jes K. Jorgensen

University of Copenhagen

Joel D. Green

Space Telescope Science Institute (STScI)

The University of Texas at Austin

Tyler L. Bourke

SKA Organisation

Astrophysical Journal

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

Vol. 891 1 61

Subject Categories

Meteorology and Atmospheric Sciences

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics



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