| Abstract : | In the Low Mass X-ray Binary (LMXB) sources, during the active accretion from the secondary star, the accumulated fuel (a mixture of Hydrogen and Helium) undergoes hydrostatic compression as more matter keeps piling up. When temperature and density conditions reach ignition levels (typically within a few hours to days), the entire fuel layer on the NS surface burns rapidly, leading to a thermonuclear burst. During these bursting episodes, the X-ray intensity rises by order of magnitude within a few seconds – reaching peak luminosities of 10**39 erg/s. The flux then exponentially decays at a slower rate (tens to hundreds of seconds).
Studying the spectral and timing properties of Thermal nuclear bursts helps us probe the fundamental properties of the Neutron stars and the accretion environment of the binary systems. This work presents our preliminary results of analyzing AstroSat data of well-known thermonuclear burst source 4U 1728-34. We report 22 type-1 thermonuclear bursts throughout 8 AstroSat observations. We have fitted the continuum with cutoff power law and a broad iron line at 6.92 +/- 0.28 keV. A time spectral analysis of the burst spectrum was also done, fitting it with blackbody radiation and examining the evolution of various parameters over time. We will present a detailed comparison of the continuums and bursts of the source, spanning over years of observation. |
