2017A&A...598A..53D


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.13CEST08:15:18

2017A&A...598A..53D - Astronomy and Astrophysics, volume 598A, 53-53 (2017/2-1)

Search for aluminium monoxide in the winds of oxygen-rich AGB stars.

DE BECK E., DECIN L., RAMSTEDT S., OLOFSSON H., MENTEN K.M., PATEL N.A. and VLEMMINGS W.H.T.

Abstract (from CDS):

Context. Aluminium monoxide (AlO) is likely efficiently depleted from the gas around oxygen-rich evolved stars to form alumina (Al2O3) clusters and dust seeds. The presence of AlO gas in the extended atmospheres of evolved stars has been derived from optical spectroscopy. More recently, AlO gas was also detected at long wavelengths around the supergiant VY CMa and the oxygen-rich asymptotic giant branch star omicron Cet (Mira A). The central role aluminium might play in dust formation and wind driving, in combination with these first detections of AlO at long wavelengths, shows the need for a wider search for this molecule in the winds of evolved stars.
Aims. The detection at long wavelengths of emission in rotational transitions of AlO towards asymptotic giant branch stars can help constrain the presence and location of AlO gas in the outflows and ultimately also the efficiency of the depletion process.
Methods. In search of AlO, we mined data obtained with APEX, the IRAM 30 m telescope, Herschel/HIFI, SMA, and ALMA, which were primarily aimed at studying other species around asymptotic giant branch stars. We report here on observations of AlO towards a sample of eight oxygen-rich asymptotic giant branch stars in different rotational transitions, up to seven for some stars.
Results. We present definite detections of one rotational transition of AlO for omicron Cet and R Aqr, and tentative detections of one transition for R Dor and omicron Cet and two transitions for IK Tau and W Hya. The presented spectra of WX Psc, R Cas, and TX Cam show no signature of AlO. For omicron Cet, R Aqr, and IK Tau, we find that the AlO (N=9-8) emission likely traces the inner parts of the wind, out to only a few tens of AU, where the gas has not yet been accelerated to its terminal velocity. This is in agreement with recently published results from a detailed study on omicron Cet.
Conclusions. The conclusive detections of AlO emission in the case of omicron Cet and R Aqr confirm the presence of AlO in the gas phase in outflows of asymptotic giant branch stars. The tentative detections further support this. Since most of the observations presented in this study were obtained with stronger emission from other species than AlO in mind, observations with higher sensitivity in combination with high angular resolution will improve our understanding of the presence and behaviour of AlO. From the current data sets we cannot firmly conclude whether there is a direct correlation between the wind properties and the detection rate of AlO emission. We hope that this study can serve as a stimulus to perform sample studies in search of AlO in oxygen-rich outflows.

Abstract Copyright: © ESO, 2017

Journal keyword(s): stars: AGB and post-AGB - stars: mass-loss - circumstellar matter - astrochemistry - submillimeter: stars

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 IRC +10011 OH* 01 06 25.9889735162 +12 35 52.890666456   20.7   18.26 14.01 M8 396 0
2 * omi Cet Mi* 02 19 20.79210 -02 58 39.4956   7.63 6.53 5.03   M5-9IIIe+DA 1438 0
3 V* IK Tau Mi* 03 53 28.8884898148 +11 24 21.865959095 16.99 17.03 13.39 7.29 3.20 M7-11 570 0
4 V* R Dor AB* 04 36 45.59127 -62 04 37.7974 7.84 6.98 5.40 2.71 -0.44 M8III:e 282 0
5 V* TX Cam Mi* 05 00 51.1569959503 +56 10 54.093107078       14.02   M9-9.5 328 0
6 V* VY CMa s*r 07 22 58.32877 -25 46 03.2355 12.01 10.19 7.95     M5Iae 996 0
7 V* W Hya Mi* 13 49 02.0018313132 -28 22 03.532006894   8.97 7.70     M7.5-9e 598 0
8 V* W Aql S* 19 15 23.3581458294 -07 02 50.308513461   12.72 10.14     S6/6e 206 0
9 * chi Cyg S* 19 50 33.9243904 +32 54 50.609683 7.02 6.06 4.24 1.81 -0.01 S6-9/1-2e 663 0
10 V* R Aqr Sy* 23 43 49.4629939776 -15 17 04.184232557   8.823 7.683 9.37   M6.5-8.5e 736 0
11 V* R Cas Mi* 23 58 24.8700291935 +51 23 19.691977266 6.71 6.63 4.80     M6.5-9e 677 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2017A&A...598A..53D and select 'bookmark this link' or equivalent in the popup menu


2020.07.13-08:15:18

© Université de Strasbourg/CNRS

    • Contact