Binary corrected X-ray light curve of Cygnus X-3: Implications for the timing properties of the compact binary system

¹ Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400005, India
² ISRO Satellite Centre, Bangalore-560017, India
³ Dept. of Physics, Manipur University, Canchipur, Imphal, Manipur-795003, India

Corresponding author: M. Choudhury, manojulu@tifr.res.in

Received: 5 May 2003
Accepted: 9 March 2004

Abstract

We study the binary corrected X-ray light curve of Cygnus X-3 using the RXTE-ASM (All Sky Monitor) data and RXTE-PCA data. We find that the X-ray template derived from the EXOSAT observations adequately explains the binary variations. Using the recently determined quadratic binary ephemeris we correct the RXTE-PCA lightcurve and obtain the power spectrum which shows distinct features of shifting towards the low frequency regime vis-a-vis the Galactic X-ray binaries. The power spectrum doesn't vary from the hard to the soft state. We also obtain the binary corrected RXTE-ASM monitoring lightcurve and examine the previously obtained correlation between soft X-ray (2-12 keV from RXTE ASM), hard X-ray (20-100 keV from CGRO-BATSE) and radio (2.2 GHz from GBI) after the binary correction. We find that the correlation time scale is less than a day.