C.D.S. - SIMBAD4 rel 1.7 - 2020.07.04CEST14:46:49

2018A&A...617A..23B - Astronomy and Astrophysics, volume 617A, 23-23 (2018/9-1)

Molecular line study of the S-type AGB star W Aquilae. ALMA observations of CS, SiS, SiO and HCN.


Abstract (from CDS):

Context. With the outstanding spatial resolution and sensitivity of the Atacama Large Millimeter/sub-millimeter Array (ALMA), molecular gas other than the abundant CO can be observed and resolved in circumstellar envelopes (CSEs) around evolved stars, such as the binary S-type asymptotic giant branch (AGB) star W Aquilae.
Aims. We aim to constrain the chemical composition of the CSE and determine the radial abundance distribution, the photospheric peak abundance, and isotopic ratios of a selection of chemically important molecular species in the innermost CSE of W Aql. The derived parameters are put into the context of the chemical evolution of AGB stars and are compared with theoretical models.
Methods. We employ one-dimensional radiative transfer modeling - with the accelerated lambda iteration (ALI) radiative transfer code-of the radial abundance distribution of a total of five molecular species (CS, SiS, 30SiS, 29SiO and H13CN) and determine the best fitting model parameters based on high-resolution ALMA observations as well as archival single-dish observations. The additional advantage of the spatially resolved ALMA observations is that we can directly constrain the radial profile of the observed line transitions from the observations.
Results. We derive abundances and e-folding radii for CS, SiS, 30SiS, 29SiO and H13CN and compare them to previous studies, which are based only on unresolved single-dish spectra. Our results are in line with previous results and are more accurate due to resolution of the emission regions.

Abstract Copyright: © ESO 2018

Journal keyword(s): stars: abundances - stars: AGB and post-AGB - circumstellar matter - stars: mass-loss - stars: winds, outflows - submillimeter: stars

Simbad objects: 6

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Number of rows : 6

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
1 V* R Scl C* 01 26 58.0946233986 -32 32 35.437732667 17.26 9.59 5.72 3.69 2.30 C-N5+ 297 0
2 IRC +10216 C* 09 47 57.40632 +13 16 43.5648     10.96     C9,5e 2133 0
3 V* RW LMi C* 10 16 02.2834693816 +30 34 18.977096332       15.27   C4,3e 379 0
4 QSO B1908-202 QSO 19 11 09.65289198 -20 06 55.1089891   18.21   18.14   ~ 235 0
5 V* W Aql S* 19 15 23.3581458294 -07 02 50.308513461   12.72 10.14     S6/6e 206 0
6 QSO B1921-293 BLL 19 24 51.05595514 -29 14 30.1210524   18.71 18.21 15.07   ~ 689 0

    Equat.    Gal    SGal    Ecl

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