PACS and SPIRE spectroscopy of the red supergiant VY CMa
2010 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 518, L145- p.Article in journal (Refereed) Published
With a luminosity > 10(5) L-circle dot and a mass-loss rate of similar to 2 x 10(-4) M-circle dot 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 similar to 1.3:1, and that chemical non-equilibrium processes determine the abundance fractions in the inner envelope.
Place, publisher, year, edition, pages
2010. Vol. 518, L145- p.
line: identification, stars: chemically peculiar, circumstellar matter, stars: mass-loss, supergiants
IdentifiersURN: urn:nbn:se:su:diva-51699DOI: 10.1051/0004-6361/201014641ISI: 000281527200146OAI: oai:DiVA.org:su-51699DiVA: diva2:385721
authorCount :372011-01-122011-01-122011-01-12Bibliographically approved