220 citations · 1.5k across the 63 of their papers we have counts for
17 papers · 1 filter
The emergence of X-ray emission lines during relativistic radio-jet formation in the changing-look active galactic nucleus 1ES 1927+654
Dev R. Sadaula, Sibasish Laha, Eileen T. Meyer +27
We present results from a comprehensive multi-wavelength monitoring campaign of the changing-look active galactic nucleus 1ES 1927+654 during the onset and evolution of a relativis…
Study of mass outflows from magnetized accretion disks around rotating black holes with thermal conduction
Camelia Jana, Monu Singh, Suvendu Rakshit +1
We examine mass outflows from a low-angular momentum, viscous, advective, and magnetized accretion disk around a rotating black hole in presence of thermal conduction. We consider…
Multi-wavelength observations of a jet launch in real time from the post-changing-look Active Galaxy 1ES 1927+654
Sibasish Laha, Eileen T. Meyer, Dev R. Sadaula +34
We present results from a high cadence multi-wavelength observational campaign of the enigmatic changing look AGN 1ES 1927+654 from May 2022- April 2024, coincident with an unprece…
Testing particle acceleration in blazar jets with continuous high-cadence optical polarization observations
Ioannis Liodakis, Sebastian Kiehlmann, Alan P. Marscher +44
Variability can be the pathway to understanding the physical processes in astrophysical jets, however, the high-cadence observations required to test particle acceleration models a…
A Case for a Binary Black Hole System Revealed via Quasi-Periodic Outflows
Dheeraj R. Pasham, Francesco Tombesi, Petra Sukova +33
Binaries containing a compact object orbiting a supermassive black hole are thought to be precursors of gravitational wave events, but their identification has been extremely chall…
A re-emerging bright soft-X-ray state of the changing-look Active Galactic Nucleus 1ES~1927+654: a multi-wavelength view
Ritesh Ghosh, Sibasish Laha, Eileen Meyer +24
1ES1927+654 is a nearby active galactic nucleus that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of mont…
The first look at Narrow-Line Seyfert 1 Galaxies with eROSITA
G. Grünwald, Th. Boller, S. Rakshit +6
We present the first look at the spectral and timing analysis of Narrow-Line Seyfert 1 Galaxies (NLS1s) with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA)…
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…
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…
Host galaxy properties of quasi-periodically erupting X-ray sources
T. Wevers, D. R. Pasham, P. Jalan +2
Quasi-periodic X-ray eruptions (QPEs) are a recently discovered phenomenon, the nature of which remains unclear. Based on their discovery in active galactic nuclei (AGN), explanati…
Correlation between optical and -ray flux variations in BL Lacs
Bhoomika Rajput, Zahir Shah, C. S. Stalin +2
We report here results on the analysis of correlated flux variations between the optical and GeV -ray bands in three bright BL Lac objects, namely AO\, 0235+164, OJ 287 and PKS…
TXS 1206+549: a new -ray detected narrow-line Seyfert 1 galaxy at redshift 1.34?
Suvendu Rakshit, Malte Schramm, C. S. Stalin +5
Radio and -ray loud narrow-line Seyfert 1 galaxies (NLS1s) are unique objects to study the formation and evolution of relativistic jets, as they are believed to have high accret…
Long term optical and infrared variability characteristics of Fermi Blazars
P. Z. Safna, C. S. Stalin, Suvendu Rakshit +1
We present long term optical and near infrared flux variability analysis of 37 blazars detected in the -ray band by the {\it Fermi Gamma-Ray Space Telescope}. Among them, 30 are…
A comparison of X-ray photon indices among the narrow and broad-line Seyfert 1 galaxies
Vineet Ojha, Hum Chand, Gulab Chand Dewangan +1
We present a detailed comparative systematic study using a sample of 221 Narrow-line Seyfert 1 (NLSy1) galaxies in comparison to a redshift matched sample of 154 Broad-line Seyfert…
Long term γ -ray variability of blazars
Bhoomika Rajput, C. S. Stalin, Suvendu Rakshit
We used the data from the Fermi Gamma-ray Space Telescope to characterise the γ-ray flux variability of blazars on month-like time scales. Our sample consists of 1120 blazars of wh…
Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3
Bhoomika Rajput, C. S. Stalin, S. Sahayanathan +2
Blazars show optical and -ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based…
Gamma-ray Emitting Narrow Line Seyfert 1 Galaxies in The Sloan Digital Sky Survey
Vaidehi S. Paliya, M. Ajello, S. Rakshit +4
The detection of significant -ray emission from radio-loud narrow line Seyfert 1 (NLSy1s) galaxies enables us to study jets in environments different than those in blazars. Howe…