X-Ray Emission of Nova Puppis 1991: Accretion or a Shocked Shell?
Abstract
Nova Puppis 1991 (V351 Pup) was observed and detected in X-rays by the ROSAT Position Sensitive Proportional Counter 16 months after the visual maximum with a count rate of 0.223±0.005 counts s-1. With follow-up optical observations we determined the value E(B - V) = 0.3±0.1 for the interstellar absorption and D = 4.7±0.6 kpc as the distance to the nova. The best spectral fit to the X-ray data is a model of thermal plasma at temperature kT ≃ 1.1 keV and source flux fx ≃ 3 x 1012 ergs cm-2 s-1 in the range 0.2-2.4 keV, implying an X-ray source luminosity of 7.5 x 1033 ergs s-1. The source brightness varied between the two ROSAT exposures taken 2 days apart. The X-ray emission could be due to restored accretion at a very high rate or to shocks in the ejected shell; it does not have the characteristics of a "supersoft" thermal X-ray source associated with nuclear burning on a white dwarf. Nova Puppis 1991 is the third classical nova that emits hard X-rays, among five that have been observed by ROSAT during outburst.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1996
- DOI:
- 10.1086/177520
- Bibcode:
- 1996ApJ...466..410O
- Keywords:
-
- STARS: BINARIES: CLOSE;
- STARS: INDIVIDUAL CONSTELLATION NAME: NOVA PUPPIS 1991;
- STARS: NOVAE;
- CATACLYSMIC VARIABLES;
- X-RAYS: STARS