Arghajit Jana

ACCRETION FLOW PROPERTIES OF MAXI J1543–564 DURING 2011 OUTBURST FROM THE TCAF SOLUTION

We derive accretion flow properties of the transient black hole candidate (BHC) MAXI J1543–564 using the RXTE data. We use the two-component advective flow (TCAF) solution to fit the data of the initial rising phase of outburst (from 2011 May 10 to 15). The 2.5–25 keV spectra are fitted using the TCAF solution fits file as a local additive table model in XSPEC. We extract physical flow parameters such as the two-component (Keplerian disk and sub-Keplerian halo) accretion rates and size and the property of the Compton cloud (post-shock region close to a black hole). Similar to other classical transient BHCs, monotonic evolution of low-frequency quasi-periodic oscillations (QPOs) is observed during the rising phase of the outburst, which is fitted with the propagating oscillatory shock (POS) model, which describes how the Compton cloud properties change from day to day. From the nature of variations of TCAF model fitted physical flow parameters and QPOs, we only found hard-intermediate and soft-intermediate spectral states during this phase of the outburst under study. We also calculated the frequency of the dominating QPOs from the TCAF model fitted shock parameters and found that they roughly match with the observed and POS model fitted values. From our spectro-temporal study of the source with TCAF and POS models, the most probable mass of the BHC is found to be 12.6–14.0 M ⊙, or .

ACCRETION FLOW DYNAMICS OF MAXI J1836-194 DURING ITS 2011 OUTBURST FROM TCAF SOLUTION

The Galactic transient X-ray binary MAXI~J1836-194 was discovered on 29th August 2011. Here we make a detailed study of the spectral and timing properties of its 2011 outburst using archival data of RXTE Proportional Counter Array instrument. The evolution of accretion flow dynamics of the source during the outburst through spectral analysis with Chakrabarti-Titarchuks two-component advective flow (TCAF) solution as a local table model in XSPEC. We also fitted spectra with combined disk blackbody and power-law models and compared it with the TCAF model fitted results. The source is found to be in hard and hard-intermediate spectral states only during entire phase of this outburst. No soft or soft-intermediate spectral states are observed. This could be due to the fact that this object belongs to a special class of sources (e.g., MAXI~J1659-152, Swift~J1753.5-0127, etc.) that have very short orbital periods and that companion is profusely mass-losing or the disk is immersed inside an excretion disk. In these cases, flows in the accretion disk is primarily dominated by low viscous sub-Keplerian flow and the Keplerian rate is not high enough to initiate softer states. Low-frequency quasi-periodic oscillations (QPOs) are observed sporadically although as in normal outbursts of transient black holes, monotonic evolutions of QPO frequency during both rising and declining phases are observed. From the TCAF fits, we find mass of the black hole in the range of

Estimation of the mass of the black hole candidate MAXI J1659−152 using TCAF and POS models

7.5-11~M_\odot

Properties of X-Ray Flux of Jets during the 2005 Outburst of Swift J1753.5−0127 Using the TCAF Solution

and from time differences between peaks of the Keplerian and sub-Keplerian accretion rates we obtain viscous timescale for this particular outburst

Accretion Flow Properties of Swift J1753.5-0127 during Its 2005 Outburst

\sim 10

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

~days.

Properties of the Black Hole XTE J1118+480 with the TCAF Solution in 2000 During its Jet activity induced Outburst

The Galactic transient black hole candidate (BHC) MAXI~J1659-152 exhibited temporal and spectral evolution during its very first X-ray outburst (2010) after its discovery on 25th Sept. 2010. Our recent studies of a few transient BHCs including MAXI~J1659-152 using Chakrabarti-Titarchuk two-component advective flow (TCAF) solution as an additive table local model in XSPEC revealed details of accretion flow dynamics around the black hole (BH). The TCAF model fitted normalization (N) comes out to be almost constant throughout the entire outburst consisting of several spectral states. We introduce two independent methods to determine the mass (

Possible ASTROSAT observation of transient black hole candidates to study spectral and timing properties with TCAF solution

M_{BH}

Accretion flow dynamics of a few transient black hole candidates from their spectral evolution study using TCAF solution

) of the BHC, namely, {\it

Temporal and spectral properties of MAXI J1659-152 during its 2010 outburst

i)