45 citations · 175 across the 13 of their papers we have counts for
8 papers · 1 filter
Investigating X-ray Emission from Radio-detected Broad- and Narrow-line Seyfert 1 Galaxies
Minhua Zhou, Minfeng Gu, Lei Xu +2
Context: This paper presents a study of the X-ray emission for a sample of radio-detected (RD-) broad- and narrow-line Seyfert 1 galaxies (NLS1s and BLS1s). Aims: To investigate th…
Multi-band optical photometric variability of the blazar OJ 287 from 2015 to 2025
Alok C. Gupta, Karan Dogra, Mark Kidger +101
We present the most densely sampled multi-band optical photometric observations of the peculiar BL Lacertae object OJ 287 from 2015 to 2025 with a focus on its optical activity on…
Multiband Optical Variability of the Blazar 3C 454.3 on Diverse Timescales
Karan Dogra, Alok C. Gupta, C. M. Raiteri +79
Due to its peculiar and highly variable nature, the blazar 3C 454.3 has been extensively monitored by the WEBT team. Here, we present for the first time these long-term optical flu…
Study of variability in long-term multiwavelength optical lightcurves of blazar AO 0235+164
Abhradeep Roy, Alok C. Gupta, Varsha R. Chitnis +9
We present a long-term and intraday variability study on optical multiwaveband () data from the blazar AO 0235+164 collected by various telescopes for 44 years (19…
X-ray emission of radio-loud quasar SDSS J121426.52+140258.9: independent variations between optical/UV and X-ray emission
Minhua Zhou, Minfeng Gu, Mai Liao +1
To understand the X-ray emission of active galactic nuclei (AGNs), we explored the optical-to-X-ray variation correlation of a radio-loud quasar (RLQ) SDSS J121426.52+140258.9 (her…
Long-term optical spectroscopic variations in blazar 3C 454.3
Krzysztof Nalewajko, Alok C. Gupta, Mai Liao +3
Characterisation of the long-term variations in the broad line region in a luminous blazar, where Comptonisation of broad-line emission within a relativistic jet is the standard sc…
Intra-day variability of three Seyfert Galaxies measured with XMM-Newton
Ashutosh Tripathi, Paul J. Wiita, Alok C. Gupta +2
We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest ( ks) observations made for NGC…
A peculiar multi-wavelength flare in the Blazar 3C 454.3
Alok C. Gupta, Arun Mangalam, Paul J. Wiita +20
The blazar 3C454.3 exhibited a strong flare seen in gamma-rays, X-rays, and optical/NIR bands during 3--12 December 2009. Emission in the V and J bands rose more gradually than did…