Abstract Details

Name: SNEHA MUDAMBI
Affiliation: Christ (Deemed to be University), Bengaluru
Conference ID: ASI2019_103
Title : Broadband spectral studies of LMC X-1 using AstroSat
Authors and Co-Authors : M. Sneha Prakash (1), A. Rao (2), S. B. Gudennavar (1), R. Misra (3) and S. G. Bubbly (1) (1) Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Road, Bengaluru-560029, India. (2) Department of Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton SO17 1BJ, UK 0000-0003-3105-2615. (3) Inter-University Centre for Astronomy and Astrophysics, Ganeshkind, Pune-411007, India
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : LMC X-1, a persistent high mass black hole binary system, has been monitored by all major X-ray missions till date in its high soft state. Since its discovery in 1969, LMC X-1 has never transitioned to a low hard state. Interestingly, LMC X-1 is highly luminous, however its luminosity does not follow Stefan’s law. Its ability to maintain a constant luminosity of ∼ 0.16 LEdd, despite showing significant fluctuations in the rms amplitude of its power density spectrum, has intrigued researchers over the last three decades. Though several models - relativistic disk model, perturbation propagation model - have been put forward to explain this unusual behaviour, none of them are successful. In this work, we will report the results of the first broadband spectral studies of the LMC X-1 as observed by Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counters (LAXPC) instruments aboard AstroSat. Unlike, most other X-ray binaries, the distance to the source is well constrained and hence the broad band spectral studies (0.3-30 keV) would provide an accurate measurement of the system's accretion rate. Likewise, the flux resolved spectroscopy will provide the information about how the high energy component, arising from a Comptonizing medium surrounding the disk, varies with accretion rate, thereby giving insights to the dynamical geometry of the inner most regions close to the blackhole. This work will also demonstrate AstroSat's capability to do broad band (0.3-30 keV) timing studies for such faint (~ 20 mcrab) source by cross-correlating the light curves from the two instruments- SXT and LAXPC.