Abstract Details
| Name: Blessy Baby Affiliation: ISAC, Bengaluru Conference ID: ASI2019_165 Title : Spectro-Temporal Analysis of 4U 1630-472 during its 2018 outburst with AstroSat Authors and Co-Authors : Blessy E.B., V. K. Agrawal, Ramadevi M.C., Tilak Katoch, Anuj Nandi. Abstract Type : Oral Abstract Category : Stars, ISM and Galaxy Abstract : 4U 1630-472 is classified as a black hole candidate based on its spectral and timing properties. It is a recurrent X ray transient which undergoes regular outbursts with a period between 600 and 730 d. This source was recently in an outburst as detected by MAXI and Swift on the 4th of June, 2018. The Hardness Intensity Diagram(HID) of the source obtained from MAXI observation of 2018 outburst, shows that the source does not undergo canonical state transitions. Under ToO campaign, the source was observed with AstroSat during the period of August 04 to September 17, 2018. We analysed all the data available with SXT and LAXPC observations in the energy range 0.7-50 keV, with the aim of discerning the evolution of the source during the outburst.The broadband spectra were fitted with the phenomenological models. The source is mostly found to be in the soft state with photon-index(Γ) ranging from ~ 2.0 – 3.0. The inner disk temperature is found to vary between 1.25 and 1.40 kT. Rms variability of < 3% is seen in the range 0.01 – 10 Hz, but no QPO's are detected in all the obervations. In this work, we present a comparison between the spectral and timing evolution of the latest outburst observed with Astrosat and that of the 1999 outburst observed with RXTE. We also comment on the possible physical scenarios to explain the observed spectral and timing properties. |