J/A+A/629/A146 ALMA data cubes for IRC+10216 (Velilla-Prieto+, 2019)
IRC+10 216 mass loss properties through the study of λ3mm emission:
Large spatial scale distribution of SiO, SiS, and CS.
Velilla-Prieto L., Cernicharo J., Agundez M., Fonfria J.P.,
Quintana-Lacaci G., Marcelino N., Castro-Carrizo A.
<Astron. Astrophys. 629, A146 (2019)>
=2019A&A...629A.146V 2019A&A...629A.146V (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Radio lines
Keywords: stars: AGB and post-AGB - circumstellar matter -
stars: individual: IRC+10216
Abstract:
Low-mass evolved stars are major contributors to interstellar medium
enrichment as a consequence of the intense mass-loss process these
stars experience at the end of their lives. The study of the gas in
the envelopes surrounding asymptotic giant branch (AGB)stars through
observations in the millimetre wavelength range provides information
about the history and nature of these molecular factories. Here we
present ALMA observations at subarsecond resolution, complemented with
IRAM-30m data, of several lines of SiO, SiS, and CS towards the
best-studied AGB circumstellar envelope, IRC+10 216. We aim to
characterise their spatial distribution and determine their fractional
abundances mainly through radiative transfer and chemical modelling.
The three species display extended emission with several enhanced
emission shells. CS displays the most extended distribution reaching
distances up to ap-proximately 20". SiS and SiO emission have similar
sizes of approximately 11", but SiS emission is slightly more compact.
We have estimated fractional abundances relative to H2, which on
average are equal to f(SiO)∼10-7, f(SiS)∼10-6, and f(CS)∼10-6 up
to the photo-dissociation region. The observations and analysis
presented here show evidence that the circumstellar material displays
clear deviations from an homogeneous spherical wind, with clumps and
low density shells that may allow UV photons from the interstellar
medium (ISM) to penetrate deep into the envelope, shifting the
photo-dissociation radius inwards. Our chemical model predicts
photo-dissociation radii compatible with those derived from the
observations, although it is unable to predict abundance variations
from the starting radius of the calculations (∼10R☉), which may
reflect the simplicity of the model. We conclude that the spatial
distribution of the gas proves the episodic and variable nature of the
mass loss mechanism of IRC+10 216, on timescales of hundreds of years
Description:
Data cubes in fits-format that correspond to the merged ALMA and
IRAM-30 m observations of the following lines (of the ground
vibrational state): SiO J=2-1, 29SiO J=2-1, 30SiO J=2-1,
SiS J=5-4, 29SiS J=5-4, 30S iS J=5-4, Si34S J=5-4, SiS J=6-5,
29SiS J=6-5, 30SiS J=6-5, Si34S J=6-5, CS J=2-1, 13CS J=2-1,
C34S J=2-1, and C33S J=2-1.
Objects:
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RA (2000) DE Designation(s)
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09 47 57.446 +13 16 43.86 IRC+10216 = CW Leo
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 113 15 List of datacubes
fits/* . 15 Indifidual datacubes
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See also:
J/A+A/330/676 : IRC+10216 Silicon and sulfur chemistry (Willacy+ 1998)
J/ApJS/177/275 : 1.3 and 2mm survey of IRC+10216 (He+, 2008)
J/ApJS/190/348 : 1mm spectral survey of IRC+10216 + VY CMa (Tenenbaum+, 2010)
J/ApJS/193/17 : Spectral-line survey of IRC+10216 at 293-355GHz (Patel+, 2011)
J/A+A/545/A12u : Chemistry of IRC+10216 inner wind modelled (Cherchneff, 2012)
J/A+A/574/A56 : IRC+10216 17.8GHz-26.3GHz spectrum (Gong+, 2015)
J/ApJ/806/L3 : Disilicon carbide (SiCSi) discovery in CW Leo
(Cernicharo+, 2015)
J/A+A/601/A4 : IRC+10216 carbon chains mapped with ALMA (Agundez+, 2017)
J/A+A/606/A74 : IRC+10216 13.3GHz-18.5GHz spectrum (Zhang+, 2017)
J/A+A/618/A4 : IRC+10216 as a spectroscopic laboratory (Cernicharo+, 2018)
J/ApJ/688/L83 : Detection of C5N- in IRC +10216 (Cernicharo+, 2008)
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- 31 I2 --- Nz Number of slices
33- 40 F8.1 m/s bVRAD Lower value of VRAD interval
42- 50 F9.3 m/s BVRAD Upper value of VRAD interval
52- 58 F7.3 m/s dVRAD VRAD resolution
60- 65 I6 Kibyte size Size of FITS file
67- 80 A14 --- FileName Name of FITS file, in subdirectory fits
82-113 A32 --- Title Title of the FITS file
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Acknowledgements:
Luis Velilla-Prieto, luis.velilla(at)chalmers.se
(End) Luis Velilla-Prieto [Chalmers, Sweden], Patricia Vannier [CDS] 13-Aug-2019