Timing and Spectral Analysis of Thermonuclear X-ray Burst from LMXB 4U 1636-536

Thermonuclear X -ray burst

Abstract

Here we are presenting the results of Thermonuclear X-ray burst of 4U1636-536 using ASTROSAT/LAXPC data during the year 2017.  Light curve analysis of this source reveals 12 thermonuclear X-ray burst like events.  All the bursts are very strong and the burst peak to persistent intensity < 9 times except two burst B2 and B10.  Energy resolved burst profile shows the burst like event disappear above 30 keV. We fitted each burst in different energy range with model BURS and found that the decay time decreases with energy.  For the spectral analysis, nH value was frozen to 0.25 atoms /cm^2. Time resolved spectral analysis shows that the flux and spectral data counts showed a maximum value at the peak time of each burst. The flux tends to show a decreasing manner after the peak time with respect to time duration.