4 μm spectra of AGB stars I. Observations

Autor(en)
Thomas Lebzelter, Kenneth H. Hinkle, Bernhard Aringer
Abstrakt

We present times series of high resolution spectra of AGB variables at 4 œm. Line profiles from the major contributors to the spectra of oxygen-rich stars at 4 œm, OH, H2O, HCl and SiO, are examined. The velocity as well as shape variations of these profiles with time are discussed. The line profiles investigated frequently have emission and multiple absorption components. The changes with time of the 4 œm region lines do not always follow the cyclic variability seen in NIR spectra and in the photometric light curve. We interpret and discuss the results qualitatively considering comparing the spectral variability with that of the well behaved 1.6 œm region and of dynamical model atmospheres. Miras and semiregular variables are compared. The origins of non-periodic behavior are discussed, including the role of spatial inhomogeneities in the stellar atmosphere.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
National Optical Astronomy Observatory, Tucson, Università degli Studi di Padova
Journal
Astronomy & Astrophysics
Band
377
Seiten
617-630
Anzahl der Seiten
14
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20010994
Publikationsdatum
2001
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/a45f0b5a-9298-44aa-aedf-ae0fa22fdf0f