The Supersoft X-Ray Source CAL 83: A Massive White Dwarf
Abstract
We have obtained Chandra HRC-S/LETG spectroscopy of the prototypical supersoft source CAL 83 in the Large Magellanic Cloud. The data reveal a very rich absorption line spectrum from the hot white dwarf photosphere. We have recently completed the analysis of the Chandra spectrum and of an earlier XMM-Newton RGS spectrum of CAL 83 with new non-LTE line-blanketed model atmospheres that explicitly include 74 ions of the 11 most abundant species. We have successfully matched the Chandra and XMM-Newton spectra, and have thus derived the basic stellar parameters of the hot white dwarf. In particular, we have obtained the first direct spectroscopic evidence that the white dwarf is massive (M > 1Msolar). We also found no spectral signatures of a wind from the white dwarf. These results provide direct support for supersoft sources as likely progenitors of SN Ia.
- Publication:
-
Interacting Binaries: Accretion, Evolution, and Outcomes
- Pub Date:
- October 2005
- DOI:
- 10.1063/1.2130249
- Bibcode:
- 2005AIPC..797..313L
- Keywords:
-
- X-ray binary stars;
- white dwarfs;
- stellar atmospheres;
- stellar mass;
- 97.80.Jp;
- 97.20.Rp;
- 97.10.Ex;
- X-ray binaries;
- Faint blue stars white dwarfs degenerate stars nuclei of planetary nebulae;
- Stellar atmospheres;
- radiative transfer;
- opacity and line formation