X-Ray Variability of the Magnetic Cataclysmic Variable V1432 Aquilae and the Seyfert Galaxy NGC 6814
Abstract
V1432 Aquilae (=RX J1940.2-1025) is the X-ray-bright, eclipsing magnetic cataclysmic variable ~37' away from the Seyfert galaxy NGC 6814. Because of a 0.3% difference between the orbital (12,116.3 s) and the spin (12,150 s) periods, the accretion geometry changes over the ~50 day beat period. Here we report the results of a Rossi X-Ray Timing Explorer campaign to observe the eclipse 25 times, as well as of archival observations with ASCA and BeppoSAX. Having confirmed that the eclipse is indeed caused by the secondary, we use the eclipse timings and profiles to map the accretion geometry as a function of the beat phase. We find that the accretion region is compact and that it moves relative to the center of white dwarf on the beat period. The amplitude of this movement suggests a low-mass white dwarf, in contrast to the high mass previously estimated from its X-ray spectrum. The size of the X-ray emission region appears to be larger than in other eclipsing magnetic cataclysmic variables. We also report on the RXTE data as well as the long-term behavior of NGC 6814, indicating flux variability by a factor of at least 10 on timescales of years.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2003
- DOI:
- 10.1086/378318
- arXiv:
- arXiv:astro-ph/0307195
- Bibcode:
- 2003ApJ...597..479M
- Keywords:
-
- Stars: Binaries: Eclipsing;
- Galaxies: Individual: NGC Number: NGC 6814;
- Galaxies: Seyfert;
- Stars: Novae;
- Cataclysmic Variables;
- Stars: Individual: Constellation Name: V1432 Aquilae;
- X-Rays: Binaries;
- X-Rays: Galaxies;
- Astrophysics
- E-Print:
- 44 pages including 16 figures