J/A+A/633/A7 IRAS 16293-2422 spectral cubes (van 't Hoff+, 2020)
Temperature profiles of young disk-like structures: The case of IRAS 16293A.
van 't Hoff M.L.R., van Dishoeck E.F., Jorgensen J.K., Calcutt H.
<Astron. Astrophys. 633, A7 (2020)>
=2020A&A...633A...7V 2020A&A...633A...7V (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Infrared sources ; Spectroscopy
Keywords: stars: formation - stars: protostars - ISM: molecules -
ISM: individual objects: IRAS 16293-2422
Abstract:
Temperature is a crucial parameter in circumstellar disk evolution and
planet formation because it governs the resistance of the gas to
gravitational instability and sets the chemical composition of the
planet-forming material. We set out to determine the gas temperature
of the young disk-like structure around the Class 0 protostar IRAS
16293-2422A.
We used Atacama Large Millimeter/submillimeter Array (ALMA)
observations of multiple H2CS J=7-6 and J=10-9 lines from the
Protostellar Interferometric Line Survey (PILS) to create a
temperature map for the inner ∼200AU of the disk-like structure. This
molecule is a particularly useful temperature probe because
transitions between energy levels with different K_a quantum numbers
operate only through collisions.
Based on the H2CS line ratios, the temperature is between ∼100-175K
in the inner ∼150AU, and drops to ∼75K at ∼200AU. At the current
resolution (0.5"∼70AU), no jump is seen in the temperature at the
disk-envelope interface. The temperature structure derived from H2CS
is consistent with envelope temperature profiles that constrain the
temperature from 1000AU scales down to ∼100AU, but does not follow the
temperature rise seen in these profiles at smaller radii. Higher
angular resolution observations of optically thin temperature tracers
are needed to establish whether cooling by gas-phase water, the
presence of a putative disk, or the dust optical depth influences the
gas temperature at ≲100AU scales. The temperature at 100AU is higher
in IRAS 16293A than in the embedded Class 0/I disk L1527, consistent
with the higher luminosity of the former.
Description:
This data collection contains 34 spectral cubes (RA, Dec, Frequency)
extracted from the ALMA-PILS dataset (ALMA project IDs 2012.1.00712.S
and 2013.100278.S) and 1 spectral cube from ALMA dataset
2016.1.01150.S (PI: V. Taquet). Additional reduction and processing
issues are given in Jorgensen et al. (2016A&A...595A.117J 2016A&A...595A.117J) and
Taquet et al. (2018A&A...618A..11T 2018A&A...618A..11T). Each FITS file represents a
small frequency range around the formaldehyde or thioformaldehyde
lines listed in Table A.1 in the paper.
Objects:
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RA (2000) DE Designation(s)
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16 32 22.56 -24 28 31.8 IRAS 16293 = IRAS 16293-2422
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 181 35 List of fits datacubes
fits/* . 35 Individual 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- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz Number of slices
32- 57 A26 "datime" Obs.date Observation date
59- 69 E11.6 Hz bFREQ Lower value of frequency interval
71- 81 E11.6 Hz BFREQ Upper value of frequency interval
83- 88 I6 Hz dFREQ Frequency resolution
90- 95 I6 Kibyte size Size of FITS file
97-131 A35 --- FileName Name of FITS file, in subdirectory fits
133-181 A49 --- Title Title of the FITS file
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Acknowledgements:
Merel van 't Hoff, vthoff(at)strw.leidenuniv.nl
(End) Patricia Vannier [CDS] 26-Nov-2019