PACS and SPIRE spectroscopy of the red supergiant VY CMa

Author(s)
Pierre Royer, Leen Decin, Roger Wesson, Michael J. Barlow, Edward Polehampton, Mikako Matsuura, Marcelino Agundez, Joris A D L Blommaert, Jos Cernicharo, Martin Cohen, Fabien Daniel, Pieter Degroote, Wim De Meester, Katrina Exter, Helmut Feuchtgruber, Walter K Gear, Haley L. Gomez, Martin A. T. Groenewegen, Peter Hargrave, Rik Huygen, Peter Imhof, Rob J. Ivison, Christophe Jean, Franz Kerschbaum, Sarah Jane Leeks, Tanya Lim, Robin Lombaert, Göran Olofsson, Thomas Posch, Sara Regibo, Giorgio Savini, Bruce Sibthorpe, Bruce M Swinyard, Bart Vandenbussche, Christoffel Waelkens, Dugan K. Witherick, Jeremy Yates
Abstract

With a luminosity >105  and a mass-loss rate of ~2 × 10-4  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.

Organisation(s)
Department of Astrophysics
External organisation(s)
Katholieke Universiteit Leuven, University College London, University of Lethbridge, Université de recherche Paris Sciences et Lettres, Spanish National Research Council (CSIC), University of California, Berkeley, Max-Planck-Institut für extraterrestrische Physik, Cardiff University, Royal Observatory of Belgium, Blue Sky Spectroscopy, UK Astronomy Technology Centre, Rutherford Appleton Laboratory, Stockholm University, The Royal Observatory, Edinburgh
Journal
Astronomy & Astrophysics
Volume
518
No. of pages
5
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/201014641
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
107003 History of natural sciences, 103004 Astrophysics
Portal url
https://ucrisportal.univie.ac.at/en/publications/323e0e2b-8e3b-4b78-aa83-f62359ece28b