106 citations · 1.3k across the 67 of their papers we have counts for
32 papers · 1 filter
Spectral Properties of GX~339--4 in the Intermediate State Using AstroSat Observation
Arghajit Jana, Debjit Chatterjee, Hsiang-Kuang Chang +2
We present the results obtained from the spectral studies of black hole X-ray binary GX~339--4 using \astrosat~ observations during its 2021 outburst. \astrosat~ observed the sourc…
Broadband X-ray spectral analysis of the ULX NGC 1313\,X-1 using JeTCAF: Origin of the ULX bubble
Biswaraj Palit, Santanu Mondal
NGC 1313\,X-1 is a mysterious Ultra-luminous X-ray (ULX) source whose X-ray powering mechanism and a bubble-like structure surrounding the source are topics of intense study. Here,…
Spectral and Temporal Studies of Swift\,J1658.2--4242 using {\it AstroSat} Observations with {\tt JeTCAF} Model
Santanu Mondal, V. Jithesh
We present the X-ray spectral and temporal analysis of the black hole X-ray transient Swift J1658.2--4242 observed by {\it AstroSat}. Three epochs of data have been analysed using…
Evolution of low frequency quasi-periodic oscillations in GX 339-4 during its 2021 outburst using AstroSat data
Santanu Mondal, Anirudh Salgundi, Debjit Chatterjee +3
The black hole X-ray binary GX\,339-4 showed an X-ray outburst during 2021. The {\it AstroSat} captured this outburst when the source entered into the intermediate flux state while…
Misaligned jets from Sgr A and the origin of Fermi/eROSITA bubbles
Kartick C. Sarkar, Santanu Mondal, Prateek Sharma +1
One of the leading explanations for the origin of Fermi Bubbles is a past jet activity in the Galactic center supermassive black hole Sgr A. The claimed jets are often assumed…
Study of accretion flows around an ultraluminous X-ray source M82 X-1 using NuSTAR data
Santanu Mondal, Biswaraj Palit, Sandip K. Chakrabarti
We study the spectral properties and accretion flow behavior of an ultraluminous X-ray source M82\,X-1 using {\it NuSTAR} observations. We use the physical two component advective…
Variable mass accretion and failed wind explain changing look phenomena in NGC 1365
Santanu Mondal, Tek P. Adhikari, Krzysztof Hryniewicz +2
Changing look active galactic nuclei (CLAGNs) show complex nature in their X-ray spectral shape and line of sight column density variation. The physical mechanisms responsible for…
Flux and spectral variability of Mrk 421 during its moderate activity state using NuSTAR: Possible accretion disc contribution?
Santanu Mondal, Priyanka Rani, C. S. Stalin +2
The X-ray emission in BL Lac objects is believed to be dominated by synchrotron emission from their relativistic jets. However, when the jet emission is not strong, one could expec…
Low Frequency Quasi Periodic Oscillations and Shocks in Accretion onto Black Hole
Chandra B. Singh, Santanu Mondal, David Garofalo
Low-frequency quasi-periodic oscillations (LFQPOs) have been routinely observed in black hole X-ray binaries (BHXRBs). These LFQPOs can be explained by axisymmetric shock oscillati…
Fermi bubbles: the collimated outburst needed to explain forward-shock edges
Santanu Mondal, Uri Keshet, Kartick C. Sarkar +1
The bipolar, nonthermal, high-latitude lobes known as the Fermi bubbles (FBs) are thought to originate from a massive energy release near the Galactic centre (GC). We constrain the…
Spectral signature of mass outflow in Two Component Advective Flow Paradigm
Santanu Mondal, Sandip K. Chakrabarti
Outflows are common in many astrophysical systems. In the Two Component Advective Flow ({\fontfamily{qcr}\selectfont TCAF}) paradigm which is essentially a generalized Bondi flow i…
Emission lines from X-ray illuminated accretion disc in black hole binaries
Santanu Mondal, Tek P. Adhikari, Chandra B. Singh
X-ray flux from the inner hot region around central compact object in a binary system illuminates the upper surface of an accretion disc and it behaves like a corona. This region c…
Changing Accretion Geometry of Seyfert 1 Mrk 335 with {\it NuSTAR}: A Comparative Study
Santanu Mondal, C. S. Stalin
We present a detailed spectral study of the narrow-line Seyfert~1 galaxy, Markarian~335, using eight epoch observations made between 2013 and 2020 with the Nuclear Spectroscopic Te…
Spectral properties of NGC 4151 and the Estimation of black hole mass using TCAF solution
Prantik Nandi, Sandip K. Chakrabarti, Santanu Mondal
We present X-ray spectral analysis of Seyfert 1.5 Active Galactic Nuclei (AGN) NGC~4151 using \textit{NuSTAR} observation during 2012. This is the first attempt to fit an AGN data…
Evolution of spectral and temporal properties of MAXI J1836-194 during 2011 outburst
Arghajit Jana, Dipak Debnath, Sandip K. Chakrabarti +3
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 Flo…
Implications on accretion flow dynamics from spectral study of Swift~J1357.2-0933
Santanu Mondal, Sandip K Chakrabarti
We report a detailed spectral study of Swift~J1357.2-0933 low-mass X-ray binary during its 2017 outburst using {\it Swift} and {\it NuSTAR} observations. We fit the data with two c…
Possible range of viscosity parameter to trigger black hole candidates to exhibit different states of outbursts
Santanu Mondal, Sandip K. Chakrabarti, Shreeram Nagarkoti +1
In a two component advective flow around a compact object, a high viscosity Keplerian disk is flanked by a low angular momentum and low viscosity flow which forms a centrifugal pre…
Accretion Flow Properties of Swift J1753.5-0127 during its 2005 outburst
Dipak Debnath, Arghajit Jana, Sandip K. Chakrabarti +2
Galactic X-ray binary black hole candidate Swift~J1753.5-0127 was discovered on June 30 2005 by Swift/BAT instrument. In this paper, we make detailed analysis of spectral and timin…
Estimation of Mass of Compact Object in H 1743-322 from 2010 and 2011 Outbursts using TCAF Solution and Spectral Index - QPO Frequency Correlation
Aslam Ali Molla, Sandip K. Chakrabarti, Dipak Debnath +1
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…
Accretion Flow Properties of MAXI J1543-564 During 2011 Outburst from TCAF Solution
Debjit Chatterjee, Dipak Debnath, Sandip K. Chakrabarti +2
We derive accretion flow properties of the transient black hole candidate (BHC) MAXI~J1543-564 using the RXTE data. We use Two-Component Advective Flow (TCAF) solution to fit the d…
Estimation of Mass of the Black Hole Candidate MAXI J1659-152 using TCAF and POS Models
Aslam Ali Molla, Dipak Debnath, Sandip K. Chakrabarti +2
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 S…
Spectral study of GX 339-4 with TCAF using Swift/XRT and NuSTAR Observation
Santanu Mondal, Sandip K. Chakrabarti, Dipak Debnath
We fit spectra of galactic transient source GX~339-4 during its 2013 outburst using Two Component Advective Flow (TCAF) solution. For the first time, we are fitting combined NuSTAR…
Accretion flow dynamics of MAXI J1836-194 during its 2011 outburst from TCAF solution
Arghajit Jana, Dipak Debnath, Sandip K. Chakrabarti +2
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 usin…
Spectral and Temporal Properties of MAXI J1836-194 during 2011 Outburst
A. Jana, D. Debnath, S. Mondal +3
We study black hole candidate (BHC) MAXI~J1836-194 during its 2011 outburst with Two Component Advective Flow (TCAF) model using RXTE/PCU2 data in ~keV band. From spectral…