Accretion Flow Dynamics of Maxi j1836-194 During Its 2011 Outburst From Tcaf Solution

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To understand accretion flow dynamics around black hole candidates (BHCs) one needs to study spectral as well as temporal features in details. After the inclusion of Chakrabarti-Titarchuk two Component Advective Flow (TCAF) model into HEASARC's spectral analysis package XSPEC as a local additive table model, we found that it is quite capable of fitting spectra from different phases of few transient black hole candidates (TBHCs) during their X-ray outbursts. From spectral fits with TCAF model, one can directly extract physical flow parameters, such as two types of accretion (Keplerian disk and sub-Keplerian halo) rates and shock parameters (location and strength of the shock). A much better understanding of spectral and timing properties is achieved by studying evolution of these physical flow parameters during the outbursts of TBHCs. One can also predict frequency of primary dominating QPOs from TCAF fitted shock parameters. Based on a comparison of halo to disk accretion rate ratio (ARR) with quasi-periodic oscillation (QPOs; if present) frequencies, a physical understanding of the classification of the entire outburst phase of the BHCs into different spectral states emerges. We conclude that TCAF in XSPEC, provides us with a better tool to understand accretion flow dynamics during the outbursts of TBHCs.

Section: Mass Estimation Of Unknown Bhcsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Debnath¹,

Chakrabarti²,

Mondal³

et al. 2017

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“…In our recent study of MAXI objects (MAXI J1659-152, MAXI J1836-194, MAXI J1543-564), we observed that if we allow mass of the BHCs to vary in a small range while fitting spectra with TCAF solution, model normalization (which is a fraction 1 4πD 2 sin(i), where 'D' is the source distance in units of 10 kpc and 'i' is the disk inclination angle) comes out roughly in a constant 9,11 . This allows us to predict most preferable range of the mass of an unknown BHC, which could also be verified from POS model 2,3,12-14 fitted QPO frequency evolutions during rising and declining phases of the outbursts.…”

Section: Mass Estimation Of Unknown Bhcsmentioning

confidence: 99%

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

Debnath¹,

Chakrabarti²,

Mondal³

et al. 2017

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ASTROSAT is India's first multi-wavelength astronomy satellite, was successfully launched on 2015 September 28 by PSLV in a ∼ 650 km near-equatorial orbit. It can be used to study astronomical objects in a wide range of electromagnetic energy band from UV to hard X-rays. With a very high spectral, timing as well as spacial resolutions from different scientific instruments of the satellite, one can make a detailed spectral and timing study of transient black hole candidates (BHCs) during their outbursts. Recently, we have included Chakrabarti-Titarchuk (1995) Two-Component Advective Flow (TCAF) model in HEASARC's spectral analysis package XSPEC as a local additive table model to fit black hole with the model, and we found that it is quite capable of explaining both the spectral and temporal properties of BHCs very successfully. Multi-wavelength data of ASTROSAT is expected to provide some useful data to understand spectral as well as temporal variability of transient BHCs using TCAF solution. Here, we discuss various aspects of TCAF which can be verified from ASTROSAT data.

“…In general, these objects show different spectral states (hard (HS), hard Intermediate (HIMS), Soft Intermediate (SIMS) and Soft (SS), and low frequency quasi-periodic oscillations (QPOs) in some of these states (1,2,3). The spectral evolution of states in BH transients are also found to be associated with different branches of a physical hysteresis diagram, accretion rate ratio vs X-ray intensity (ARRID; see, Jana et al 4 ). Different branches of this diagram are found to be related with different observed spectral states.…”

Section: Introductionmentioning

confidence: 99%

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

Molla¹,

Debnath²,

Chakrabarti³

et al. 2017

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Transient black hole candidate MAXI J1659-152 showed rapid spectral and temporal evolution during its very first outburst. Our understanding about accretion flow dynamics around black hole candidates has improved much more after the inclusion of Chakrabarti-Titarchuk Two Component Advective Flow (TCAF) model as an additive table model in XSPEC. In this paper we make a detail study of temporal and spectral properties of black hole candidate MAXI J1659-152 during its 2010 outburst with TCAF and POS model. From our fit, we extract accretion flow parameters (Keplerian disk and sub-Keplerian halo rates, shock location, shock strength). We find mass of the object to be 4.17-7.74 M .