Constraining the Infalling Envelope Models of Embedded Protostars: BHR 71 and its Hot Corino

Abstract

The collapse of the protostellar envelope results in the growth of the 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 HCO${}^{+}$ $J=4\to 3$ and CS $J=7\to 6$ lines, and the low velocity emission of the HCN $J=4\to 3$ line. The envelope has a model-derived age of 12000$\pm$3000 years after the initial collapse. The envelope model underestimates the high velocity emission at the HCN $J=4\to 3$ and H${}^{13}$CN $J=4\to 3$ 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 CH${}_3$OH and CH${}_3$OCHO, along with H${}_2$CS, SO${}_2$ and HCN $v_2=1$. The emission of methyl formate and ${}^{13}$C-methanol shows a clear velocity gradient within a radius of 50 au, hinting at an unresolved Keplerian rotating disk.

arXiv comment42 pages, 38 figures, accepted for publication in ApJ

References in corpus (51)

• Astropy: A Community Python Package for Astronomy
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Physical Conditions in Regions of Star Formation
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• Physical structure and CO abundance of low-mass protostellar envelopes
• A Rigorous Attempt to Verify Interstellar Glycine
• Molecular Inventories and Chemical Evolution of Low-mass Protostellar Envelopes
• Water in star-forming regions with Herschel (WISH): II. Evolution of 557 GHz 110-101 emission in low-mass protostars
• LIME - a flexible, non-LTE line excitation and radiation transfer method for millimeter and far-infrared wavelengths
• HYPERION: An open-source parallelized three-dimensional dust continuum radiative transfer code
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Protostellar Core Formation
• Evolution of Chemistry and Molecular Line Profile during Protostellar Collapse
• Infall, Outflow, Rotation, and Turbulent Motions of Dense Gas within NGC 1333 IRAS 4
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Magnetohydrodynamic Effects and Early Formation of Circumstellar Disks
• Testing grain surface chemistry : a survey of deuterated formaldehyde and methanol in low-mass Class 0 protostars
• Infalling-Rotating Motion and Associated Chemical Change in the Envelope of IRAS 16293-2422 Source A Studied with ALMA
• eXtended CASA Line Analysis Software Suite (XCLASS)
• The first ALMA view of IRAS 16293-2422: Direct detection of infall onto source B and high-resolution kinematics of source A
• CO rovibrational emission as a probe of inner disk structure
• Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Key Program: Continuum SEDs, and an Inventory of Characteristic Far-Infrared Lines from PACS Spectroscopy
• Complex Structure in Class 0 Protostellar Envelopes
• A recent accretion burst in the low-mass protostar IRAS 15398-3359: ALMA imaging of its related chemistry
• Formation and Atmosphere of Complex Organic Molecules of the HH 212 Protostellar Disk
• Probing Pre-Protosellar Cores with Formaldehyde
• Molecular freeze-out as a tracer of the thermal and dynamical evolution of pre- and protostellar cores
• L483: Warm Carbon-Chain Chemistry Source Harboring Hot Corino Activity
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• Unveiling the Evolutionary Sequence from Infalling Envelopes to Keplerian Disks around Low-Mass Protostars
• Detection of Infall in the Protostar B335 with ALMA
• The Lyman-alpha signature of the first galaxies
• B335: A Laboratory for Astrochemistry in a Collapsing Cloud
• The organic chemistry in the innermost, infalling envelope of the Class 0 protostar L483
• Rotational spectra of isotopic species of methyl cyanide, CH${}_3$CN, in their ground vibrational states up to terahertz frequencies
• Protostar Formation in Supersonic Flows: Growth and Collapse of Spherical Cores
• Subarcsecond Analysis of Infalling-Rotating Envelope around the Class I Protostar IRAS 04365+2535
• ATCA and Spitzer Observations of the Binary Protostellar Systems CG30 and BHR71
• IRAS 11590-6452 in BHR 71 - a binary protostellar system?
• Prestellar Core Formation, Evolution, and Accretion from Gravitational Fragmentation in Turbulent Converging Flows
• A grid of 1D low-mass star formation collapse models
• CO and CH3OH observations of the BHR71 outflows with APEX
• The Formation Conditions of the Wide Binary Class 0 Protostars within BHR 71
• Laboratory spectroscopic study of isotopic thioformaldehyde, H${}_2$CS, and determination of its equilibrium structure
• CO in Protostars (COPS): $Herschel$-SPIRE Spectroscopy of Embedded Protostars
• Revisiting the shocks in BHR71: new observational constraints and H2O predictions for Herschel
• Radiative effects during the assembly of direct collapse black holes
• The Class 0 Protostar BHR71: Herschel Observations and Dust Continuum Models
• Impacts of pure shocks in the BHR71 bipolar outflow
• JCMT POL-2 and ALMA polarimetric observations of 6000-100 au scales in the protostar B335: linking magnetic field and gas kinematics in observations and MHD simulations

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• The Perseus ALMA Chemistry Survey (PEACHES). I. The Complex Organic Molecules in Perseus Embedded Protostars
• The THESAN project: Lyman-alpha emission and transmission during the Epoch of Reionization
• H-alpha emission in local galaxies: star formation, time variability and the diffuse ionized gas
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• JWST Observations of Young protoStars (JOYS): overview of program and early results
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Hot Corino Survey toward Protostellar Cores in the Orion Cloud
• Organic chemistry in the protosolar analogue HOPS-108: Environment matters
• Importance of source structure on complex organics emission. I. Observations of CH${}_3$OH from low-mass to high-mass protostars
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): I. Detection of New Hot Corinos with ACA
• Methanol deuteration in high-mass protostars
• Importance of source structure on complex organics emission II. Can disks explain lack of methanol emission from some low-mass protostars?
• Hot corino chemistry in the Class I binary source Ser-emb 11
• Models of Rotating Infall for the B335 Protostar
• Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST. IV
• Physical and Chemical Structure of the Disk and Envelope of the Class 0/I Protostar L1527
• FERIA: Flat Envelope Model with Rotation and Infall under Angular Momentum Conservation
• FAUST VII. Detection of A Hot Corino in the Prototypical Warm Carbon-Chain Chemistry Source IRAS 15398-3359
• SO2 and OCS toward high-mass protostars: A comparative study between ice and gas
• ALMA ACA study of the H${}_2$S/OCS ratio in low-mass protostars
• A Catalog of Molecular Clumps and Cores with Infall Signatures
• FAUST XV. A disk wind mapped by CH${}_3$OH and SiO in the inner 300 au of the NGC 1333 IRAS 4A2 protostar
• Nobeyama Survey of Inward Motions toward Cores in Orion Identified by SCUBA-2
• Early Planet Formation in Embedded Disks (eDisk). XI. A high-resolution view toward the BHR 71 Class 0 protostellar wide binary
• Survival of Molecular Complexity under Recent Supernova Feedback: Detection of Hot Cores in RX J1713.7-3946
• Which molecule traces what: chemical diagnostics of protostellar sources