X-ray variability of the magnetic cataclysmic variable V1432 Aquilae and the Seyfert galaxy NGC 6814

被引:24
作者
Mukai, K
Hellier, C
Madejski, G
Patterson, J
Skillman, DR
机构
[1] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[2] Univ Keele, Dept Phys, Keele ST5 5BG, Staffs, England
[3] Stanford Linear Accelerator Ctr, Glast Grp, Menlo Pk, CA 94025 USA
[4] Columbia Univ, Dept Astron, New York, NY 10027 USA
[5] Ctr Backyard Astrophys E, Laurel, MD 20723 USA
[6] Univ Space Res Assoc, Columbia, MD USA
[7] Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA
关键词
D O I
10.1086/378318
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
V1432 Aquilae (= RX J1940.2 - 1025) is the X-ray - bright, eclipsing magnetic cataclysmic variable similar to37' 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 similar to 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.
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页码:479 / 493
页数:15
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