155 citations · 3.1k across the 108 of their papers we have counts for
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Multi-wavelength Intra-day Variability and Quasi-periodic Oscillation in Blazars
Alok C. Gupta
We reviewed multi-wavelength blazars variability and detection of quasi-periodic oscillations on intra-day timescales. The variability timescale from few minutes to up to less than…
Multi-Band Intra-Night Optical Variability of BL Lacertae
Haritma Gaur, Alok C. Gupta, R. Bachev +5
We monitored BL Lacertae frequently during 2014 - 2016 when it was generally in a high state. We searched for intra-day variability for 43 nights using quasi-simultaneous measureme…
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…
Origin of X-rays in the low state of the FSRQ 3C 273: Evidence of inverse Compton emission
Nibedita Kalita, Alok C. Gupta, Paul J. Wiita +2
We analyze the 2.5--10 keV X-ray spectra of the luminous quasar 3C 273 and simultaneous observations in UV wavelengths from XMM--Newton between 2000 and 2015. The lowest flux level…
X-ray Intraday Variability of Five TeV Blazars with NuSTAR
Ashwani Pandey, Alok C. Gupta, Paul J. Wiita
We have examined 40 NuSTAR light curves (LCs) of five TeV emitting high synchrotron peaked blazars: 1ES 0229+200, Mrk 421, Mrk 501, 1ES 1959+650 and PKS 2155-304. Four of the blaza…
Core shift effect in blazars
A. Agarwal, P. Mohan, Alok C. Gupta +8
We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies () between 4.…