Mass estimation of MAXI J1659-152 during spectral and temporal analsyis with TCAF and POS models

The Galactic transient black hole candidate (BHC) MAXI J1659-152 showed its first X-ray outburst on 25th Spet. 2010. We make a detailed spectral and temporal study of this outburst with RXTE/PCA data. The spectral analysis was made with Two Component Advective Flow (TCAF) model fits file as an additive table model in XSPEC. While fitting spectra with TCAF, we note that model fitted normalization (N) remains almost constant (129.7 - 146.3) which lead us to calculate mass of the black hole (BH). We then refitted all the spectra with fixed normalization value of 139 (calculated from weighted averaging of the N values), and found that mass of the BH comes in the range of 4.69-7.75 M_Sun. It is to be noted that in TCAF model fits file, mass is an input parameter. We also calculted mass of the BH, with our study of the QPO frequency evolution during declining phase of the outburst with the Propagating Oscillatory Shock (POS) model. We observe that in the declining phase of the outburst the shock moves away from the black hole as the QPO frequency decreases. We obtain our best fit of QPO evolution by using mass of the BH at 6 M_Sun and acceptable fit (reduced chisq value < 1.5) for the mass range of 5.08-7.38 M_Sun, which lie within the range of mass obtained from our spectral fit. So, from the study of spectral and temporal variability of this source we conclude the probable mass range of the black hole to be 4.69 - 7.75 M_Sun.