X-ray Dip as a Probe of Orbital and Accretion Disk Dynamics for Low Mass X-ray Binary
X-ray dips in a dipping Low Mass X-ray Binary (LMXB) are believed to be owing to absorption of X-rays by vertical structure in the accretion disk. Studying the variations of X-ray dips allows us to probe the orbital and accretion disk dynamics for an LMXB. We have developed a new method to unbiasedly extract the properties of an X-ray dip, such as dip center time and dip width, and applied it to the ultra compact LMXB X1916-053. Observations by the Rossi XRay Timing Explorer from 1998 clearly show a 4.87 day periodic variation in the dip width, which is like due to nodal precession of the accretion disk. Combining more than 24 years of historical data, we find an orbital period derivative Porb/Porb = (1.62±0.34) x 1O-7yr-1. On the other hand, radiation-driven model can properly account for the period derivative. With the best ephemeris, we find that the standard deviation of the primary dips is smaller than that of the secondary dips. This means that the primary dips are more stable than the secondary dips. Thus, we conclude that the primary dips of X1916-053 occur from the bulge where the accretion stream encounters the rim of the disk, rather than the inner disk ring.
X-ray binaries stars indidual (X1916-053)
Yi Chou Chin-Ping Hu Yi-Ying Chung Ting-Chang Yang
Graduate Institute of Astronomy, National Central University, Taiwan
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
210-211
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）