2.4 - 197 micron spectroscopy of OH/IR stars: The IR characteristics of circumstellar dust in O-rich environments - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 1999

2.4 - 197 micron spectroscopy of OH/IR stars: The IR characteristics of circumstellar dust in O-rich environments

R. J. Sylvester
  • Fonction : Auteur
F. Kemper
  • Fonction : Auteur
M. J. Barlow
  • Fonction : Auteur
T. de Jong
  • Fonction : Auteur
L. B. F. M. Waters
  • Fonction : Auteur
A. G. G. M. Tielens
  • Fonction : Auteur

Résumé

Infrared spectra of a number of evolved O-rich stars have been obtained with the Short- and Long- Wavelength spectrometers on board the Infrared Space Observatory. The very broad wavelength coverage (2.4-197 micron) obtained by combining observations made with the two spectrometers includes practically all of the flux emitted by the sources, and allows us to determine the emission and absorption features of the dense circumstellar dust shells. Agreement between the fluxes obtained by the two instruments is generally very good; the largest discrepancies are probably due to source variability. Our sample of oxygen-rich AGB stars exhibits a wealth of spectral features due to crystalline silicates and crystalline water ice in emission and absorption. In this study a qualitative overview of all features due to crystalline silicates and water ice in these high mass loss rate objects is presented. It seems that there is a certain onset value for the mass loss rate above which these features appear in the spectrum. Moreover, crystalline silicate emission features have been detected for the first time at wavelengths where the amorphous silicates are still in absorption, implying different spatial distributions for the two materials. A spherically symmetric and an axi-symmetric geometry are proposed.
Fichier principal
Vignette du fichier
document.pdf (1.99 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00005500 , version 1 (30-12-2023)

Identifiants

Citer

R. J. Sylvester, F. Kemper, M. J. Barlow, T. de Jong, L. B. F. M. Waters, et al.. 2.4 - 197 micron spectroscopy of OH/IR stars: The IR characteristics of circumstellar dust in O-rich environments. Astronomy and Astrophysics - A&A, 1999, 352, pp.587. ⟨hal-00005500⟩
62 Consultations
10 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More