Study of Aperiodic Time Variation of the X-ray binary Pulsar, Centaurus X-3

Takayoshi Kohmura(Department of Earth & Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan), Shunji Kitamoto (Department of Physics, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan), Ken'ichi Torii (Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), 2-1, Wako, Saitama 351-0198, Japan)


Abstract

We present the study of the aperiodic time variation of the binary X-ray pulsar Centaurus X-3 observed with the Rossi X-Ray Timing Explorer (RXTE). The iron K lines observed from Centaurus X-3 is considered to come from a re-processing matter around the neutron star. Thus the X-rays in the energy band containing the iron K lines is expected to have a certain delay from the higher energy X-rays.

We discovered, for the first time, that the temporal variation of iron-band emission is delayed as compared with that of the other energy X-rays by 0.39$\pm$0.10 ms (1-$\sigma$ error). We also discovered that a general trend such that the higher energy X-rays are advanced in comparison with the lower energy X-rays with the exception of the iron-band.

We will present our detail analysis by using cross spectra and discuss the implications of our results.

CATEGORY: BLACK HOLE AND NEUTRON STAR BINARIES



 

Himel Ghosh
2001-08-02