The Envelope Kinematics and a Possible Disk Around the Class 0 Protostar within BHR7

Abstract

We present a characterization of the protostar embedded within the BHR7 dark cloud, based on both photometric measurements from the near-infrared to millimeter and interferometric continuum and molecular line observations at millimeter wavelengths. We find that this protostar is a Class 0 system, the youngest class of protostars, measuring its bolometric temperature to be 50.5~K, with a bolometric luminosity of 9.3~L${}_{\odot }$. The near-infrared and \textit{Spitzer} imaging show a prominent dark lane from dust extinction separating clear bipolar outflow cavities. Observations of ${}^{13}$CO ($J=2\to 1$), C${}^{18}$O ($J=2\to 1$), and other molecular lines with the Submillimeter Array (SMA) exhibit a clear rotation signature on scales $<$1300~AU. The rotation can be traced to an inner radius of $\sim$170~AU and the rotation curve is consistent with an R${}^{-1}$ profile, implying that angular momentum is being conserved. Observations of the 1.3~mm dust continuum with the SMA reveal a resolved continuum source, extended in the direction of the dark lane, orthogonal to the outflow. The deconvolved size of the continuum indicates a radius of $\sim$100~AU for the continuum source at the assumed distance of 400~pc. The visibility amplitude profile of the continuum emission cannot be reproduced by an envelope alone and needs a compact component. Thus, we posit that the resolved continuum source could be tracing a Keplerian disk in this very young system. If we assume that the continuum radius traces a Keplerian disk (R$\sim$120~AU) the observed rotation profile is consistent with a protostar mass of 1.0~$M_{\odot }$.

arXiv comment36 pages; 11 Figures, 2 Tables; Accepted to ApJ

References in corpus (43)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• The Herschel-SPIRE instrument and its in-flight performance
• The Submillimeter Array
• ALMA Survey of Lupus Protoplanetary Disks I: Dust and Gas Masses
• Gravitational Instabilities in Circumstellar Disks
• From Molecular Cores to Planet-forming Disks: A SIRTF Legacy Program
• 2-D Radiative Transfer in Protostellar Envelopes: I. Effects of Geometry on Class I Sources
• 2-D Radiative Transfer in Protostellar Envelopes: II. An Evolutionary Sequence
• The Burst Mode of Protostellar Accretion
• Spiral Density Waves in a Young Protoplanetary Disk
• On the Role of Disks in the Formation of Stellar Systems: A Numerical Parameter Study of Rapid Accretion
• A 0.2 solar mass protostar with a Keplerian disk in the very young L1527 IRS system
• A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk
• Imaging the water-snow line during a protostellar outburst
• The Herschel Orion Protostar Survey: Spectral Energy Distributions and Fits Using a Grid of Protostellar Models
• HYPERION: An open-source parallelized three-dimensional dust continuum radiative transfer code
• A Keplerian disk around a Class 0 source: ALMA observations of VLA1623A
• Formation of a Keplerian disk in the infalling envelope around L1527 IRS: transformation from infalling motions to Kepler motions
• The N2D+/N2H+ ratio as an evolutionary tracer of Class 0 protostars
• Signs of Early-Stage Disk Growth Revealed with ALMA
• Molecular Excitation and Differential Gas-Phase Depletions in the IC 5146 Dark Cloud
• Complex Structure in Class 0 Protostellar Envelopes
• Complex Structure in Class 0 Protostellar Envelopes II: Kinematic Structure from Single-Dish and Interferometric Molecular Line Mapping
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• A Flattened Protostellar Envelope in Absorption around L1157
• Extreme Active Molecular Jets in L1448C
• Observations of L1521F: a highly evolved starless core
• The ALMA view of the protostellar system HH212 - The wind, the cavity, and the disk
• Imaging chemical differentiation around the low-mass protostar L483-mm
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution
• Unveiling the Evolutionary Sequence from Infalling Envelopes to Keplerian Disks around Low-Mass Protostars
• Complex Structure in Class 0 Protostellar Envelopes III: Velocity Gradients in Non-Axisymmetric Envelopes, Infall or Rotation?
• HH 212: SMA Observations of a Remarkable Protostellar Jet
• Constraining the Envelope Structure of L1527 IRS: Infrared Scattered Light Modeling
• Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?
• Disentangling the entangled: Observations and analysis of the triple non-coeval protostellar system VLA1623
• Resolved Depletion Zones and Spatial Differentiation of N2H+ and N2D+
• ALMA observations of the kinematics and chemistry of disc formation
• The VLA Nascent Disk And Multiplicity (VANDAM) Survey of Perseus Protostars. Resolving the Sub-Arcsecond Binary System in NGC 1333 IRAS2A
• Spitzer and HHT observations of starless cores: masses and environments
• The Inner Envelope and Disk of L1527 Revealed: Gemini L'-band Scattered Light Imaging

Cited by in corpus (9)

• Characterizing young protostellar disks with the CALYPSO IRAM-PdBI survey: large Class 0 disks are rare
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• The Formation Conditions of the Wide Binary Class 0 Protostars within BHR 71
• An observational correlation between magnetic field, angular momentum and fragmentation in the envelopes of Class 0 protostars?
• Protostellar disk formation by a non-rotating, non-axisymmetric collapsing cloud: model and comparison with observations
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -XIII. Ongoing triggered star formation within clump-fed scenario found in the massive ($\sim 1500$ ${\mathrm{M}}_{\odot }$) clump
• Modeling snowline locations in protostars: The impact of the structure of protostellar cloud cores
• Constraining the Chemical Signatures and the Outburst Mechanism of the Class 0 Protostar HOPS 383
• Effects of magnetic field orientations in dense cores on gas kinematics in protostellar envelopes