Estimation of Mass of Compact Object in H 1743-322 from 2010 and 2011 Outbursts using TCAF Solution and Spectral Index - QPO Frequency Correlation

Abstract

The well known black hole candidate H~1743-322 exhibited temporal and spectral variabilities during several outbursts. Daily variation of the accretion rates and the flow geometry change on a daily basis during each of the outbursts could be understood very well using the recent implementation of two component advective flow (TCAF) solution of the viscous transonic flow equations as an additive table model in XSPEC. This has dramatically improved our understanding about the accretion flow dynamics. Most interestingly, the solution allows to treat mass of the black hole candidate as a free parameter and there mass could be estimated from spectral fits. In this paper, we fit the data of two successive outbursts of H~1743-322 in 2010 and 2011 and studied evolutions of accretion flow parameters, such as, two component (Keplerian and sub-Keplerian) accretion rates, shock location (i.e., size of the Compton cloud), etc. We assume that the model Normalization remains the same accross the states in both these outbursts. We use this to estimate mass of the black hole and found that it comes out in the range of $9.25-12.86 M_\odot$. For the sake of comparison, we also estimated mass using Photon index vs. QPO frequency correlation method which turns out to be $11.65 \pm 0.67 M_\odot$ using GRO J1655-40 as reference source. Combining these two estimates, the most probable mass of the compact object becomes $11.21^{+1.65}_{-1.96} M_\odot$.