31 citations · 230 across the 31 of their papers we have counts for
32 papers
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…
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…
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…
Quintessence-Chameleon transitions in anisotropic Kiselev model of neutron stars
M. V. Pradosh Keshav, V. Jithesh, Kenath Arun
We investigate a chameleon scalar field dynamically interacting with a Kiselev-type metric, where the static anisotropic fluid part of the metric is replaced by a density-dependent…
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…
X-Ray Spectral Variability of Thirteen TeV High Energy Peaked Blazars with XMM-Newton
P. U. Devanand, Alok C. Gupta, V. Jithesh +2
We present a comprehensive study of the X-ray spectral variability observed in 13 TeV photon emitting high energy peaked BL Lacs(HBLs). These data come from 54 XMM-Newton EPIC-PN p…
Time resolved spectroscopy of a GRS 1915+105 flare during its unusual low state using AstroSat
Sajad Boked, Bari Maqbool, V. Jithesh +3
Since its discovery in 1992, GRS 1915+105 has been among the brightest sources in the X-ray sky. However, in early 2018, it dimmed significantly and has stayed in this faint state…
Extreme photometric and polarimetric variability of blazar S4 0954+65 at its maximum optical and -ray brightness levels
C. M. Raiteri, M. Villata, M. I. Carnerero +64
In 2022 the BL Lac object S4 0954+65 underwent a major variability phase, reaching its historical maximum brightness in the optical and -ray bands. We present optical photometri…
A Search for X-ray/UV Correlation in the Reflection-Dominated Seyfert 1 Galaxy Mrk 1044
Samuzal Barua, Oluwashina K. Adegoke, Ranjeev Misra +3
Correlated variability between coronal X-rays and disc optical/UV photons provides a very useful diagnostic of the interplay between the different regions around an active galactic…
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…
Correlated variability of the reflection fraction with the X-ray flux and spectral index for Mkn 478
Samuzal Barua, V. Jithesh, Ranjeev Misra +2
The X-ray spectrum of Mkn 478 is known to be dominated by a strong soft excess which can be described using relativistic blurred reflection. Using observations from {\it XMM-Newton…
X-ray Intraday Variability of HBL Blazars with XMM-Newton
P. U. Devanand, Alok C. Gupta, V. Jithesh +1
We present an extensive study on the X-ray intraday variability of ten TeV-emitting high synchrotron peaked blazars (HBLs): 1ES 0229+200, 1ES 0414+009, PKS 0548-322, 1ES 1101-232,…
Spectral and Temporal Properties of Ultra-luminous X-ray Source NGC 55 ULX1
V. Jithesh
We investigate the spectral and temporal properties of ultra-luminous X-ray source (ULX) NGC~55~ULX1 using {\it Swift}, {\it XMM-Newton} and {\it NuSTAR} observations conducted dur…
Evidence for coronal temperature variation in Seyfert 2 ESO 103--035 using NuSTAR observations
Samuzal Barua, V. Jithesh, Ranjeev Misra +4
We report flux-resolved spectroscopic analysis of the active galactic nucleus (AGN) ESO 103--035 using \textit{NuSTAR} observations. Following an earlier work, we fit the spectra u…
Broadband Spectral and Timing Properties of MAXI J1348-630 using AstroSat and NICER Observations
V. Jithesh, Ranjeev Misra, Bari Maqbool +1
We present broadband X-ray spectral-timing analysis of the new Galactic X-ray transient MAXI~J1348--630 using five simultaneous {\it AstroSat} and {\it NICER} observations. Spectra…
Unveiling the broadband spectral and temporal properties of PKS\,0903-57 during its brightest flare
Zahir Shah, V. Jithesh, S. Sahayanathan +1
We carried a detailed spectral and temporal study of blazar, \mbox{PKS\,0903-57} using the \emph{Fermi}-LAT and \emph{Swift}-XRT/UVOT observations, during its brightest flaring per…
Broadband X-ray Spectral Study of Ultra-luminous X-ray Source M81 X--6
V. Jithesh, C. Anjana, Ranjeev Misra
Ultra-luminous X-ray sources (ULXs) are a class of extra-galactic, point-like, off-nuclear X-ray sources with X-ray luminosity from ~erg s to ~erg s$^…
NuSTAR observation of Ark 564 reveals the variation of coronal temperature with flux
Samuzal Barua, V. Jithesh, Ranjeev Misra +3
The hard X-ray spectral index of some AGN has been observed to steepen with the source flux. This has been interpreted in a Comptonization scenario, where an increase in the soft f…
Spectral and Timing Properties of the Galactic X-ray transient Swift~J1658.2--4242 using Astrosat Observations
V. Jithesh, Bari Maqbool, Ranjeev Misra +3
We present the X-ray timing and spectral analysis of the new Galactic X-ray transient Swift J1658.2-4242 observed with LAXPC and SXT instruments onboard {\it Astrosat}. We detect p…
Study on Temporal and Spectral behavior of 3C 279 during 2018 January flare
Zahir Shah, V. Jithesh, S. Sahayanathan +2
We present a detailed temporal and spectral study of the blazar 3C\,279 using multi-wavelength observations from Swift-XRT, Swift-UVOT and Fermi-LAT during a flare in 2018 January.…
FERMI observation of the jets of the microquasar SS433
Yi Xing, Zhongxiang Wang, Xiao Zhang +2
We report our analysis of the data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi) for the SS 433/W50 region. The total data length…
Exploring the Spectral Variability of the Ultra-luminous X-ray source M81 X-6 with Suzaku and XMM-Newton
V. Jithesh, Ranjeev Misra
We present X-ray spectral variability studies of the ultra-luminous X-ray source (ULX) M81 X--6 using {\it Suzaku} and {\it XMM-Newton} observations performed during 2001--2015. Th…
Long-term Spectral Variability of the Ultra-luminous X-ray source Holmberg IX X--1
V. Jithesh, Ranjeev Misra, Zhongxiang Wang
We investigate the long-term spectral variability in the ultra-luminous X-ray source Holmberg IX X--1. By analyzing the data from eight {\it Suzaku} and 13 {\it XMM-Newton} observa…
Transient X-ray Sources in the Magellanic-type Galaxy NGC 4449
V. Jithesh, Zhongxiang Wang
We report the identification of seven transient X-ray sources in the nearby Magellanic-type galaxy NGC 4449 using the archival multi-epoch X-ray observations conducted with {\it Ch…