Evolution of spectral and temporal properties of MAXI J1836-194 during 2011 outburst

Publications

Evolution of spectral and temporal properties of MAXI J1836-194 during 2011 outburst

Author : Dr Arghajit Jana

Year : 2018

Publisher : World Scientific Publishing Co. Pte. Ltd.

Source Title : 14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Proceedings

Document Type :

Abstract

We study transient Galatic black hole candidate MAXI J1836-194 during its 2011 outburst using RXTE/PCA archival data. 2.5-25 keV spectra are fitted with Two Component Advective Flow (TCAF) model fits file as an additive table local model in XSPEC. From TCAF model spectral fits, physical parameters such as Keplerian disk rate, sub-Keplerian halo rate, shock location and compression ratio are extracted directly for better understanding of accretion processes around the BHC during this outburst. Low frequency quasi-periodic oscillation (QPO) are observed sporadically during the entire epoch of the outburst, with a general trend of increasing frequency during rising and decreasing frequency during declining phases of the outburst, as in other transient BHCs. The nature of the variation of the accretion rate ratio (ratio of halo and disk rates) and QPOs (if observed), allows us to properly classify entire epoch of the outburst into following two spectral state, such as hard (HS), hard-intermediate (HIMS). These states are observed in the sequence of HS (Ris.) → HIMS (Ris.) → HIMS (Dec.) → HS (Dec.). This outburst of MAXI J1836-194 could be termed as ‘failed’ outburst, since no observation of soft (SS) and soft-intermediate (SIMS) spectral state are found during the entire outburst.