J/A+A/677/A92 Flow of gas in Barnard 5 (Valdivia-Mena+, 2023)
Flow of gas detected from beyond the filaments to protostellar scales in
Barnard 5.
Valdivia-Mena M.T., Pineda J.E., Segura-Cox D.M., Caselli P.,
Schmiedeke A., Choudhury S., Offner S., Neri R., Goodman A., Fuller G.
<Astron. Astrophys. 677, A92 (2023)>
=2023A&A...677A..92V 2023A&A...677A..92V (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; YSOs ; Infrared sources ; Interferometry
Keywords: ISM: kinematics and dynamics - ISM: individual objects: Barnard 5 -
stars: formation - ISM: structure
Abstract:
The infall of gas from outside natal cores has proven to feed
protostars after the main accretion phase (Class 0). This changes our
view of star formation to a picture that includes asymmetric accretion
(streamers), and a larger role of the environment. However, the
connection between streamers and the filaments that prevail in
star-forming regions is unknown. We investigate the flow of material
toward the filaments within Barnard 5 (B5) and the infall from the
envelope to the protostellar disk of the embedded protostar B5-IRS1.
Our goal is to follow the flow of material from the larger, dense core
scale, to the protostellar disk scale. We present new HC3N line data
from the NOEMA and 30m telescopes covering the coherence zone of B5,
together with ALMA H2CO and C18O maps toward the protostellar
envelope. We fit multiple Gaussian components to the lines so as to
decompose their individual physical components. We investigated the
HC3N velocity gradients to determine the direction of chemically fresh
gas flow. At envelope scales, we used a clustering algorithm to
disentangle the different kinematic components within H2CO emission.
At dense core scales, HC3N traces the infall from the B5 region
toward the filaments. HC3N velocity gradients are consistent with
accretion toward the filament spines plus flow along them. We found a
∼2800 au streamer in H2CO emission, which is blueshifted with
respect to the protostar and deposits gas at outer disk scales. The
strongest velocity gradients at large scales curve toward the position
of the streamer at small scales, suggesting a connection between both
flows. Our analysis suggests that the gas can flow from the dense core
to the protostar. This implies that the mass available for a protostar
is not limited to its envelope, and it can receive chemically
unprocessed gas after the main accretion phase.
Description:
We present the original cubes and the cubes reduced in size used to
obtain the results from the paper. These include the combined NOEMA
and 30m HC3N (8-7) and (10-9) data cubes from project S18AL (PI: J.
E. Pineda) and the ALMA H2CO (303-202) and C18O (2-1) data
cubes from project 2017.1.01078.S (PI: D. Segura-Cox).
Objects:
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RA (2000) DE Designation(s)
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03 48 00.0 +32 54 00 Barnard 5 = LDN 1471
03 47 41.6 +32 51 44 Barnard 5 IRS 1 = [BJE84] IRS 1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 222 8 List of fits datacubes
fits/* . 8 Individual fits datacubes
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 32 I3 --- Nz Number of slices
34- 55 A22 "datime" Obs.date Observation date
57- 67 E11.6 m/s bVRAD ? Lower value of VRAD interval
69- 79 E11.6 m/s BVRAD ? Upper value of VRAD interval
81- 91 F11.7 m/s dVRAD ? bVRAD resolution
93-103 E11.6 Hz bFreq ? Lower value of frequency interval
105-115 E11.6 Hz BFreq ? Upper value of frequency interval
117-123 F7.1 Hz dFreq ? Frequency resolution
125-130 I6 Kibyte size Size of FITS file
132-171 A40 --- FileName Name of FITS file, in subdirectory fits
173-222 A50 --- Title Title of the FITS file
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Acknowledgements:
Maria Teresa Valdivia-Mena, mvaldivi(at)mpe.mpg.de
(End) Maria Teresa Valdivia-Mena [MPE], Patricia Vannier [CDS] 01-Aug-2023