33 citations · 242 across the 20 of their papers we have counts for
20 papers
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…
Signature of Seyfert-like component in a blazar 3C 273 and its reflection-based explanation
Haritma Gaur, Main Pal, Muhammad S. Anjum +4
We present the results of blazar 3C 273 obtained from simultaneous observations obtained using XMM-Newton and NuSTAR satellites during the period 2015-2019 in five epochs. When the…
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…
Late-time radio brightening and emergence of a radio jet in the changing-look AGN 1ES 1927+654
Eileen T. Meyer, Sibasish Laha, Onic I. Shuvo +32
We present multi-frequency (5-345 GHz) and multi-resolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic…
Simulating Superconducting Properties of Overdoped Cuprates: the Role of Inhomogeneity
Mainak Pal, Andreas Kreisel, W. A. Atkinson +1
Theoretical studies of disordered -wave superconductors have focused, with a few exceptions, on optimally doped models with strong scatterers. Addressing recent controversies ab…
Spectral States of OJ 287 blazar from Multi-wavelength Observations with
K. P. Singh, P. Kushwaha, A. Sinha +3
We present {\it AstroSat} soft X-ray, near-UV (NUV), and far-UV (FUV) observations of a blazar, OJ~287, carried out in 2017, 2018, and 2020. The simultaneous observations with NuST…
Complex optical/UV and X-ray variability in Seyfert 1 galaxy Mrk 509
Neeraj Kumari, Main Pal, Sachindra Naik +3
We performed a detailed spectral and timing analysis of a Seyfert 1 galaxy Mrk 509 using data from the Neil Gehrels Swift observatory that spanned over ~13 years between 2006 and 2…
AstroSat View of Blazar OJ 287: A complete evolutionary cycle of HBL Component from end-phase to disappearance and Re-emergence
Pankaj Kushwaha, K. P. Singh, A. Sinha +3
We report three AstroSat observations of BL Lacertae object OJ 287. The three observations caught it in very different flux states that are connected to different broadband spectra…
Spectro-Timing Analysis of a highly variable narrow-line Seyfert 1 galaxy NGC 4748 with AstroSat and XMM-Newton
Main Pal, Neeraj Kumari, Pankaj Kushwaha +8
We present a detailed timing and spectral study of an extremely variable narrow-line Seyfert~1 galaxy NGC 4748 using observations in the year 2017 and 2014 performed with AstroSat…
Blazar OJ 287 After First VHE Activity: Tracking the Re-emergence of the HBL like Component in 2020
Pankaj Kushwaha, Main Pal, Nibedita Kalita +5
We report the re-emergence of a new broadband emission through a detailed and systematic study of the multi-wavelength spectral and temporal behavior of OJ 287 after its first-ever…
Short-term X-ray Variability during Different Activity Phases of Blazars S5 0716+714 and PKS 2155-304
Pankaj Kushwaha, Main Pal
We explored the statistical properties of short-term X-ray variability using long-exposure {\it XMM-Newton} data during high X-ray variability phases of blazars S5 0716+714 and PKS…
Strong Soft X-ray Excess in 2015 XMM-Newton Observation of BL--Lac OJ~287
Main Pal, Pankaj Kushwaha, Gulab C. Dewangan +1
We report a strong soft X-ray excess in the BL--Lacartae -ray blazar OJ~287 during the long exposure in May 2015, amongst two of the latest \xmm~{} observations performed in May…
UV to X-ray Comptonization delay in Mrk 493
Oluwashina Adegoke, Gulab C. Dewangan, Pramod Pawar +1
The broadband X-ray emission from type 1 active galactic nuclei, dominated by a powerlaw continuum, is thought to arise from repeated inverse Compton scattering of seed optical/UV…
The ever-surprising blazar OJ 287: multi-wavelength study and appearance of a new component in X-rays
Pankaj Kushwaha, Alok C. Gupta, Paul J. Wiita +21
We present a multi-wavelength spectral and temporal investigation of OJ 287 emission during its strong optical-to-X-ray activity between July 2016 - July 2017. The daily -ray fl…
Correlated X-ray/UV/optical emission and short term variability in a Seyfert 1 galaxy NGC 4593
Main Pal, Sachindra Naik
We present a detailed multi-frequency analysis of an intense monitoring programme of Seyfert 1 galaxy NGC 4593 over a duration of nearly for a month with Swift observatory. We used…
Complex Optical/UV and X-ray Variability of the Seyfert 1 galaxy 1H 0419-577
Main Pal, Gulab C. Dewangan, Ajit K. Kembhavi +2
We present detailed broadband UV/optical to X-ray spectral variability of the Seyfert 1 galaxy 1H 0419-577 using six XMM-Newton observations performed during 2002-2003. These obser…
Complex UV/X-ray variability of 1H~0707-495
P. K. Pawar, G. C. Dewangan, I. E. Papadakis +3
We study the relationship between the UV and X-ray variability of the narrow-line Seyfert 1 galaxy 1H~0707-495. Using a year long {\it Swift} monitoring and four long {\it XMM-Newt…
Correlated X-ray/UV/optical variability and the nature of accretion disc in the bare Seyfert 1 galaxy Fairall~9
Main Pal, Gulab C. Dewangan, S. D. Connolly +1
We study multi-wavelength variability of a bare Seyfert 1 galaxy Fairall~9 using \swift{} monitoring observations consisting of usable pointings spanning nearly two years and…
X-ray/UV variability and the origin of soft X-ray excess emission from II Zw 177
Main Pal, Gulab C. Dewangan, Ranjeev Misra +1
We study X-ray and UV emission from the narrow-line Seyfert 1 galaxy II~Zw~177 using a $137\ks$ long and another $13\ks$ short \xmm{} observation performed in 2012 and 2001, respec…
Variable X-ray reflection from 1H~0419--577
Main Pal, Gulab C. Dewangan
We present detailed broadband X-ray spectral variability of a Seyfert 1 galaxy 1H~0419--577 based on an archival \suzaku{} observation in July 2007, a new \suzaku{} observation per…