THE UNSTABLE LONG-TERM PERIODICITY OF AQUILA X-1

被引:36
|
作者
KITAMOTO, S [1 ]
TSUNEMI, H [1 ]
MIYAMOTO, S [1 ]
ROUSSELDUPRE, D [1 ]
机构
[1] LOS ALAMOS NATL LAB,DIV SPACE SCI,LOS ALAMOS,NM 87544
关键词
STARS; INDIVIDUAL (AQUILA X-1); NEUTRON; X-RAYS; BINARIES;
D O I
10.1086/172204
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of the periodicity analysis of 4.5 yr of data observed with the All Sky Monitor (ASM) on-board Ginga and of 10 yr of data accumulated by the Vela 5b satellite. ASM observed three outbursts from Aq1 X-1 which indicate a 309 day periodicity, but Vela 5b data instead show a 125 day periodicity. This result indicates that the Aq1 X-1 long-term periodicity is not stable and therefore, cannot be due to some regular mechanism such as orbital motion or precession. This long-term periodicity may be related to some unstable mechanism such as the activity of the companion star or some instability of the accretion disk. However, no models proposed so far can completely explain the observed behavior.
引用
收藏
页码:315 / 321
页数:7
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