171 citations · 1.9k across the 85 of their papers we have counts for
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Multi-mission view of low-luminosity 'obscured' phase of GRS 1915+105
Athulya M. P., Anuj Nandi
GRS 1915+105 is observed in an 'obscured' phase since May 2019, exhibiting steady and low X-ray luminosities, while being intervened by sporadic re-brightenings. In this work, we p…
IXPE and NICER view of Black hole X-ray binary 4U 1630-47: First significant detection of polarized emission in thermal state
Ankur Kushwaha, Kiran M. Jayasurya, Vivek K. Agrawal +1
We present a detailed spectro-polarimetric study of Black hole X-ray binary 4U during its outburst with IXPE and NICER observations. The source is observed in disk…
Broadband X-ray properties of black holes GRS 1758-258 and 1E 1740.7-2942: AstroSat and NuSTAR results
Bhuvana G. R., Aneesha U., Radhika D. +4
We present the results on broadband X-ray properties of persistent black hole binaries GRS 1758258 and 1E 1740.72942 using AstroSat, NuSTAR and Swift-XRT observations carried…
AstroSat view of `Clocked` burster GS 1826-238:broad-band spectral nature of persistent and burst emission during soft state
Vivek Kumar Agrawal, Anuj Nandi, Tilak Katoch
In this paper, we have carried out a detailed study of the `Clocked' burster GS using 90 ks broad-band (0.7 - 60.0 keV) data obtained with {\it AstroSat} observat…
On the origin of core radio emissions from black hole sources in the realm of relativistic shocked accretion flow
Santabrata Das, Anuj Nandi, C. S. Stalin +5
We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that th…
Wide-band view of High Frequency QPOs of GRS 1915+105 in 'softer' variability classes observed with AstroSat
Seshadri Majumder, H. Sreehari, Nafisa Aftab +3
We present a comprehensive temporal and spectral analysis of the 'softer' variability classes (, , , , , , and ) of the source GRS 1915+105 observed by…
Unraveling the foretime of GRS 1915+105 using AstroSat observations: Wide-band spectral and temporal characteristics
Athulya M. P., Radhika D., V. K. Agrawal +4
We present a comprehensive study of GRS 1915+105 in wide energy band ( keV) using AstroSat observations during the period of . The MAXI X-ray lightcurve of the s…
Revealing the nature of the transient source MAXI J0637-430 through spectro-temporal analysis
Blessy E. Baby, Bhuvana G. R., Radhika D. +3
We study the spectral and temporal properties of MAXI J0637-430 during its 2019-2020 outburst using \textit{NICER}, \textit{AstroSat} and \textit{Swift-XRT} data. The source was in…
Multi-mission view of extragalactic black hole X-ray binaries LMC X-1 and LMC X-3: evolution of broadband spectral features
Bhuvana G. R., Radhika D., Anuj Nandi
Extragalactic black hole X-ray binaries LMC X-1 and LMC X-3 are the persistent sources, usually found in soft spectral state. We present the results from spectral and timing study…
Relativistic viscous accretion flow model for ULX sources: A case study for IC 342 X-1
Santabrata Das, Anuj Nandi, Vivek K. Agrawal +2
In this letter, we develop a model formalism to study the structure of a relativistic, viscous, optically thin, advective accretion flow around a rotating black hole in presence of…
AstroSat and MAXI view of Cygnus X-1: Signature of an `extreme' soft nature
Ankur Kushwaha, V. K. Agrawal, Anuj Nandi
We present a detailed spectral and timing analysis of Cygnus X-1 with multi-epoch observations, during to , by SXT and LAXPC on-board AstroSat. We model the spectra in…
Long-term XMM-Newton view of magnetar CXOU J010043.1721134: Comprehensive spectral and temporal results
Rwitika Chatterjee, Vivek K. Agrawal, Anuj Nandi
We present an in-depth analysis and results of eleven XMM-Newton datasets, spanning 2000 to 2016, of the anomalous X-ray Pulsar CXOU J010043.1721134 which has been classified as…
A Machine Learning approach for classification of accretion states of Black hole binaries
H Sreehari, Anuj Nandi
In this paper, we employ Machine Learning algorithms on multi-mission observations for the classification of accretion states of outbursting Black hole X-ray binaries for the first…
Broadband 'spectro-temporal' features of extragalactic black hole binaries LMC X-1 and LMC X-3: An AstroSat perspective
Bhuvana G. R., Radhika D., V. K. Agrawal +2
We present the first results of extragalactic black hole X-ray binaries LMC X-1 and LMC X-3 using all the archival and legacy observations by AstroSat during the period of $2016-20…
AstroSat view of IGR J17091-3624 and GRS 1915+105: decoding the 'pulse' in the 'Heartbeat State'
Tilak Katoch, Blessy E. Baby, Anuj Nandi +3
IGR J17091--3624 is a transient galactic black hole which has a distinct quasi-periodic variability known as `heartbeat', similar to the one observed in GRS 1915+105. In this paper…
AstroSat view of GRS 1915+105 during the Soft State: Detection of HFQPOs and estimation of Mass and Spin
Sreehari H., Anuj Nandi, Santabrata Das +4
We report the results of AstroSat observations of GRS 1915105 obtained using 100 ks guaranteed-time (GT) during the soft state. The Color-Color Diagram (CCD) indicates a variabi…
AstroSat view of LMC X-2: Evolution of broadband X-ray spectral properties along a complete Z-track
V. K. Agrawal, Anuj Nandi
In this paper, we report the first results of the extragalactic Z-source LMC X-2 obtained using the 140 ks observations with {\it Large Area X-ray Proportional Counter (LAXP…
AstroSat and MAXI view of the Black Hole binary 4U 1630-472 during 2016 and 2018 Outbursts
Blessy E. Baby, V. K. Agrawal, Ramadevi M. C. +4
We present an in-depth spectral and timing analysis of the Black Hole binary 4U 1630-472 during 2016 and 2018 outbursts as observed by \textit{AstroSat} and \textit{MAXI}. The exte…
AstroSat/LAXPC view of GX 17+2: Spectral Evolution along the Z-track
V. K. Agrawal, Anuj Nandi, M. C. Ramadevi
In this paper, we present the first results obtained using 50 ks observations of the bright low-mass X-ray binary (LMXB) GX 17+2 with Large Area X-ray Proportional Counter (…
AstroSat view of MAXI J1535-571: broadband spectro-temporal features
Sreehari H., Ravishankar B. T., Nirmal Iyer +4
We present the results of Target of Opportunity (ToO) observations made with AstroSat of the newly discovered black hole binary MAXI J1535-571. We detect prominent C-type Quasi-per…
Shocks in relativistic viscous accretion flows around Kerr black holes
I. Dihingia, Santabrata Das, Debaprasad Maity +1
We study the relativistic viscous accretion flows around the Kerr black holes. We present the governing equations that describe the steady state flow motion in full general relativ…
A Possible Model for the Long-Term Flares of Sgr A*
Toru Okuda, Chandra B. Singh, Santabrata Das +3
We examine the effects of magnetic field on low angular momentum flows with standing shock around black holes in two dimensions. The magnetic field brings change in behavior and lo…
Accretion-ejection in rotating black holes: a model for `outliers' track of radio-X-ray correlation in X-ray binaries
Ramiz Aktar, Anuj Nandi, Santabrata Das
We study the global accretion-ejection solutions around a rotating black hole considering three widely accepted pseudo-Kerr potentials that satisfactorily mimic the space-time geom…
Low angular momentum relativistic hot accretion flow around Kerr black holes with variable adiabatic index
Indu K. Dihingia, Santabrata Das, Anuj Nandi
We study the relativistic, time-independent, low angular momentum, inviscid, advective accretion flow around Kerr black hole. Considering the relativistic equation of state (REoS),…