51 citations · 191 across the 51 of their papers we have counts for
54 papers
Long-term X-ray variability of the NLS1 Ark 564
Neha P R, Nikita S Arun, Savithri H. Ezhikode +4
We present a systematic spectral study of the X-ray emission from the Narrow- Line Seyfert 1 (NLS1) galaxy Ark 564 using Swift/XRT observations spanning sixteen years. The source e…
Comparative spectro-temporal study between 1A 1246588 and 4U 0614091 using AstroSat
Suchismito Chattopadhyay, Soma Mandal, Ranjeev Misra
We present a comparative broadband spectro-temporal study of the ultra-compact X-ray binary (UCXB) candidates 1A 1246588 and 4U 0614091 using AstroSat observations. Spectral…
Long-term X-ray spectral analysis of Cygnus X-1 using AstroSat
H Lalthantluanga, Akash Garg, Ranjeev Misra +2
We performed a spectral analysis of long-term observations (2016-2019) of the black hole binary Cygnus X-1 using AstroSat, covering its hard, intermediate, and soft states. During…
Spectral evolution of NS binary system GX 349+2 using AstroSat observations
Garima Tyagi, Suchismito Chattopadhyay, Sree Bhattacherjee +3
We present a broadband spectral study of the Sco-like Z source GX 349+2 using AstroSat LAXPC and SXT observations obtained during 2019 and 2024. The X-ray light curves exhibit larg…
Complex Energy-Dependent Behaviour of Quasi-Periodic Oscillation Observed in GRS 1915+105
Vaibhav Sharma, Ranjeev Misra, V. Jithesh +5
We present complex energy-resolved properties of quasi-periodic oscillations (QPOs) in the black hole X-ray binary GRS 1915+105 using an observation from the LAXPC instrument onboa…
Probing the High-Energy Emission of the VHE-emitting Changing-Look Blazar B2 1420+32
Anjum Peer, Zahir Shah, Sikandar Akbar +2
We present a multi-wavelength temporal and spectral study of the changing-look blazar B2~1420+32 using \emph{Fermi}-LAT, \emph{Swift}-XRT, and \emph{Swift}-UVOT data from MJD~58818…
Potential detection of ~ 4.2 keV emission line from GRS 1747-312
Amom Lanchenbi Chanu, Akash Garg, Ranjeev Misra +1
We present a broadband spectral analysis of the neutron star LMXB GRS 1747-312 using 40 ks AstroSat data. The source was observed during the decay phase of the 2017 outburst…
Relativistic Scattering in the Funnel of Cygnus X-3
Suraj K. Chaurasia, Ranjeev Misra, Amit Pathak
Cygnus X-3 presents significant challenges to standard accretion models. Recent polarimetric observations by IXPE reveal high polarization degrees (PD) in the hard state ($\sim 23\…
Correlations Between kHz QPOs and Spectral Parameters from Time-Resolved Spectro-Temporal Analysis of 4U 1728-34
Kewal Anand, Ranjeev Misra, J. S. Yadav +1
We present a time-resolved analysis of the persistent emission in 4U 1728--34 using AstroSat observations from 2016 to 2019. We detect kilohertz quasi-periodic oscillations (kHz QP…
Constraining Spin and Inclination Angle of XTE J2012+381 using AstroSat and NICER
Vaibhav Sharma, Ranjeev Misra, Shivani Chaudhary +2
We present a spectral analysis of a black hole X-ray binary XTE J2012+381 during its 2022 outburst, using data from NICER and AstroSat. Combining data from NICER, LAXPC20, and SXT,…
Accretion Disk Evolution in GX 339-4 Across Spectral States Using NuSTAR, NICER, and Insight-HXMT Observations
Ruchika Dhaka, Ranjeev Misra, Suraj Kumar Chaurasia
We present a broadband spectral analysis of the black hole X-ray binary GX 339-4 during its 2021 outburst, covering both hard and soft spectral states. Using simultaneous observati…
Tracing Fe K X-ray reverberation lag in the energy-resolved spectra of Narrow-line Seyfert 1 galaxy Ton S180
Dilip Kumar Roy, Samuzal Barua, Ranjeev Misra +2
We report the Fe K relativistic reverberation feature for the first time in the Narrow-line Seyfert\,1 galaxy Ton\,S180. Using a long observation from {\it XMM-Newton} we find that…
Neuro-Parametric Spectral Classification of Black Hole and Neutron Star X-ray Binary Systems
Akash Garg, Aman Kumar, Ajit Kembhavi +5
We perform the classification of black hole and neutron star X-ray binary systems using deep neural networks applied to archival RXTE X-ray spectral data. We first construct two ne…
Evolution of the 2021 Outburst of GX 339-4 with AstroSat
Vaibhav Sharma, Ranjeev Misra, J S Yadav +2
We present a comprehensive study of the 2021 outburst of GX 339-4 using AstroSat observations in the hard-intermediate (HIMS) and soft-intermediate states (SIMS). Spectral and timi…
Spectral State Switching in Mrk 421: Results from the AstroSat LAXPC/SXT Observations
Sikandar Akbar, Zahir Shah, Ranjeev Misra +1
We carried a detailed time and flux resolved X-ray spectral analysis of the high-synchrotron-peaked blazar Mrk\,421 using simultaneous LAXPC20 and SXT observations. The 100\,s binn…
Multiwavelength spectral and temporal analysis of VHE Blazar 1ES 1959+650: Tracing emission mechanisms across flux states
Peer Anjum, Athar A. Dar, Zahir Shah +2
The high-synchrotron-peaked BL Lac object 1ES\,1959+650 exhibited pronounced activity between MJD~60310 -- 60603, including a very high energy (VHE) detection reported by LHAASO. T…
Synchrotron radiation from NGC 470 HLX1 - a hidden hyperluminous accreting neutron star?
Tanuman Ghosh, Shiv Sethi, Gulab Chand Dewangan +3
We present the first broadband spectral analysis of NGC 470 HLX1, a hyperluminous X-ray source that exhibits significant flux variability over different epochs. We investigate the…
The strong Fe K line and spin of the black-hole X-ray binary MAXI J1631-479
Andrzej A. Zdziarski, Swadesh Chand, Gulab Dewangan +5
We study the transient black hole binary MAXI J1631--479 in its soft spectral state observed simultaneously by the NICER and NuSTAR instruments. Its puzzling feature is the presenc…
Probing the Origin of X-ray Flares in the Low-Hard State of GRS 1915+105 Using AstroSat and NuSTAR
Shahzada Akhter, Sajad Boked, Bari Maqbool +2
We performed a detailed time-resolved spectral study of GRS 1915+105 during its low-flux rebrightening phase using the broadband capabilities of AstroSat and NuSTAR in May-June 201…
Probing the energy-dependent temporal nature of MAXI J1803-298 with AstroSat and NICER
Arbind Pradhan, Akash Garg, Ranjeev Misra +1
We performed the spectral and temporal analysis of MAXI J1803-298 using AstroSat/LAXPC and NICER observations taken in May 2021 during the initial phase of the outburst. We found t…
Quasi-Periodic Oscillations due to radiative feedback mechanism between the disc and corona
Akash Garg, Ranjeev Misra, Somasri Sen
Compact object systems exhibit Quasi-Periodic Oscillations (QPOs) as revealed by peaked features in their power density spectra. It has been known that stochastic variations in the…
Spectral evolution of GX 17+2 using AstroSat and NICER observations
Sree Bhattacherjee, Ranjeev Misra, Biplob Sarkar +3
We study the spectral evolution of the Z-track source GX 17+2 using AstroSat and NICER observations taken between 2016 and 2020. The AstroSat observations cover the period when the…
Indication for Dual Periodic Signatures in PKS 0805-07 from Multi-technique Time Series Analysis
Sikandar Akbar, Zahir Shah, Ranjeev Misra +2
We report the identification of two statistically significant quasi-periodic oscillations in the weekly binned -ray light curve of the flat-spectrum radio quasar PKS 080507,…
Statistical Insights into Flux and Photon Index Distributions of VHE FSRQs from Fermi-LAT Observations
Zahoor Malik, Sikandar Akbar, Zahir Shah +8
This study examines the flux and photon index distributions of 11 Very High Energy (VHE) Flat Spectrum Radio Quasars (FSRQs) using over 16 years of Fermi-LAT -ray data. The dist…