Institut für Astronomie und Astrophysik Abteilung Astronomie Sand 1, D-72076 Tübingen, Germany
Hinweis: Einige Seiten auf astro.uni-tuebingen.de können veraltet sein und werden nicht mehr aktualisiert. Note: Some webpages at astro.uni-tuebingen.de may be outdated and will no longer be updated.

Preprint 8/12

Chandra grating spectroscopy of three hot white dwarfs

J. Adamczak (1,2), K. Werner (1), T. Rauch (1), S. Schuh (3), J.J. Drake (4), J.W. Kruk (5)

(1) IAAT
(2) University of Texas, Austin
(3) Universität Göttingen
(4) CfA, Cambridge
(5) NASA GSFC

To be published in: A&A

Abstract. High-resolution soft X-ray spectroscopic observations of single hot white dwarfs are scarce. With the Chandra Low-Energy Transmission Grating, we have observed two white dwarfs, one is of spectral type DA (LB 1919) and the other is a non-DA of spectral type PG1159 (PG 1520+525). The spectra of both stars are analyzed, together with an archival Chandra spectrum of another DA white dwarf (GD 246). The soft X-ray spectra of the two DA white dwarfs are investigated in order to study the effect of gravitational settling and radiative levitation of metals in their photospheres. LB 1919 is of interest because it has a significantly lower metallicity than DAs with otherwise similar atmospheric parameters. GD 246 is the only white dwarf known that shows identifiable individual iron lines in the soft X-ray range. For the PG1159 star, a precise effective temperature determination is performed in order to confine the position of the blue edge of the GW Vir instability region in the HRD. (abridged)
 

Astrophysics (astro-ph): 1208.4478

[Home Page] [Preprints 2012] [Quick Reference] [Feedback]

| Impressum Last modified 27 Aug 2012