The ISO Long Wavelength Spectrometer line spectrum of VY Canis Majoris and other oxygen-rich evolved stars

Abstract

The far-infrared spectra of circumstellar envelopes around various oxygen-rich stars were observed using the ISO Long Wavelength Spectrometer (LWS). We have examined high signal-to-noise ISO LWS observations of the luminous supergiant star, VY CMa, with the aim of identifying all of the spectral lines. By paying particular attention to water lines, we aim to separate the lines due to other species, in particular, to prepare for forthcoming observations that will cover the same spectral range using Herschel PACS and at higher spectral resolution using Herschel HIFI and SOFIA. We have developed a fitting method to account for blended water lines using a simple weighting scheme to distribute the flux. We have applied this approach to several other stars which we compare with VY CMa. We present line fluxes for the unblended H2O and CO lines, and present detections of several possible nu_2=1 vibrationally excited water lines. We also identify blended lines of OH, one unblended and several blended lines of NH3, and one possible detection of H3O+.

15 pages, 6 figures, accepted for publication in A&A

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Cited by in corpus (6)

• Fundamental properties and atmospheric structure of the red supergiant VY CMa based on VLTI/AMBER spectro-interferometry
• Comparative Spectra of Oxygen-Rich vs. Carbon-Rich Circumstellar Shells: VY Canis Majoris and IRC+10216 at 215-285 GHz
• The Impact of Recent Advances in Laboratory Astrophysics on our Understanding of the Cosmos
• Searching for Cool Dust in the Mid-to-Far Infrared: the Mass Loss Histories of The Hypergiants $\mu$ Cep, VY CMa, IRC+10420, and $\rho$ Cas
• PACS and SPIRE Spectroscopy of the Red Supergiant VY CMa
• Herschel SPIRE and PACS observations of the red supergiant VY CMa: analysis of the molecular line spectra