Back to Search Start Over

PACS and SPIRE spectroscopy of the red supergiant VY CMa*

Authors :
Royer, P.
Decin, L.
Wesson, R.
Barlow, M. J.
Polehampton, E. T.
Matsuura, M.
Agúndez, M.
Blommaert, J. A. D. L.
Cernicharo, J.
Cohen, M.
Daniel, F.
Degroote, P.
De Meester, W.
Exter, K.
Feuchtgruber, H.
Gear, W. K.
Gomez, H. L.
Groenewegen, M. A. T.
Hargrave, P. C.
Huygen, R.
Imhof, P.
Ivison, R. J.
Jean, C.
Kerschbaum, F.
Leeks, S. J.
Lim, T.
Lombaert, R.
Olofsson, G.
Posch, T.
Regibo, S.
Savini, G.
Sibthorpe, B.
Swinyard, B. M.
Vandenbussche, B.
Waelkens, C.
Witherick, D. K.
Yates, J. A.
Source :
Astronomy and Astrophysics; July 2010, Vol. 518 Issue: 1
Publication Year :
2010

Abstract

With a luminosity >105$L_{\odot}$and a mass-loss rate of ~2 × 10-4$M_{\odot}$yr-1, the red supergiant VY CMa truly is a spectacular object. Because of its extreme evolutionary state, it could explode as supernova any time. Studying its circumstellar material, into which the supernova blast will run, provides interesting constraints on supernova explosions and on the rich chemistry taking place in such complex circumstellar envelopes. We have obtained spectroscopy of VY CMa over the full wavelength range offered by the PACS and SPIRE instruments of Herschel, i.e. 55–672 micron. The observations show the spectral fingerprints of more than 900 spectral lines, of which more than half belong to water. In total, we have identified 13 different molecules and some of their isotopologues. A first analysis shows that water is abundantly present, with an ortho-to-para ratio as low as ~1.3:1, and that chemical non-equilibrium processes determine the abundance fractions in the inner envelope.

Details

Language :
English
ISSN :
00046361 and 14320746
Volume :
518
Issue :
1
Database :
Supplemental Index
Journal :
Astronomy and Astrophysics
Publication Type :
Periodical
Accession number :
ejs53146301
Full Text :
https://doi.org/10.1051/0004-6361/201014641