针对Cygnus X-2的X射线观测
摘要
We report on a joint BEppoSAX/RossiXTE observation of the Z-type low mass X-ray binary Cyg X-2. The source was in the so-called high overall intensity state and in less than 24 hours went through all three branches of the Z-track. The continuum x-ray spectrum could be described by the absorbed sum of a soft thermal component, modeled as either a blackbody or a multicolor disk blackbody, and a Comptonized component. The timing power spectrum showed several components including quasiperiodic oscillations in the range 28-50 Hz while the source was on the horizontal branch (horizontal branch oscillation; HBO). We found that the HBO frequency was well correlated with the parameters of the soft thermal component in the x-ray spectrum. We discuss implications of this correlation for models of the HBO.
引用
@article{arxiv.astro-ph/0110553,
title = {X-Ray Observations of Cygnus X-2},
author = {S. Piraino and A. Santangelo and P. Kaaret},
journal= {arXiv preprint arXiv:astro-ph/0110553},
year = {2007}
}
备注
22 pages, accepted to the Astrophysical Journal