7 citations · 7 across the 8 of their papers we have counts for
9 papers
Intranight optical monitoring of eight quasars with superluminal jets and low optical polarization: Probing the mechanism of rapid flux variability
Krishan Chand, Gopal-Krishna, Ashutosh Tomar +3
Intranight optical variability (INOV) of blazars whose emission arises predominantly from a relativistic jet, has been widely linked to a combination of two key observational diagn…
Search for intranight optical variability in a large sample of intermediate-mass black holes
Himanshu Sharma, Gopal-Krishna, Vibhore Negi +3
Using the extensive archival database of the Zwicky Transient Facility (ZTF) survey, we have investigated intranight optical variability (INOV) in a large sample of low-mass active…
Evidence for in-situ acceleration of relativistic particles in the wings of X-shaped radio galaxies
Dusmanta Patra, Gopal-Krishna, Ravi Joshi
We report evidence for in-situ acceleration/re-acceleration of relativistic particles in 11 radio wings out of a total of 68 wings sufficiently well-resolved for spectral mapping,…
The alternating 'changing-look' blazar OQ 334 (B2 1420+32): New observational clues to the blazar state transitions
Krishan Chand, Gopal-Krishna
The high-luminosity blazar OQ 334 is a leading exponent of the intriguing rare phenomenon of alternating between a flat-spectrum radio quasar (FSRQ) and a BL Lac (BLL) states. Its…
Weak-emission-line quasars: A new clue from their optical variability
Ritish Kumar, Gopal-Krishna, Hum Chand +1
Weak-emission-line QSOs (WLQs) are an enigmatic subclass of the QSO population, as their optical/UV spectra are marked by abnormally weak (or absent) emission lines. To obtain much…
Cosmic ray contributions from rapidly rotating stellar mass black holes: Cosmic Ray GeV to EeV proton and anti-proton sources
M. L. Allen, P. L. Biermann, A. Chieffi +12
In Radio Super Novae (RSNe) a magnetic field of is observed; these are the same numbers for Blue Supe…
Intranight optical monitoring of the rare quasar J0950+5128, the brightest known candidate for transition from radio-quiet to radio-loud state
Krishan Chand, Gopal-Krishna, Hum Chand
We report a novel pilot project to characterise intra-night optical variability (INOV) of an extremely rare type of quasar, which has recently been caught in the act of transiting…
GPS in the cosmos
Gopal-Krishna
This note chronicles the early steps and incidences from over four decades ago, that gave a kickstart to research on the now prominent subclass of radio galaxies, called 'Gigahertz…
Clues on the nature of the quasi-periodic optical outbursts of the blazar OJ 287
Gopal-Krishna
The fascination with the blazar OJ 287 stems not only from its status as a prominent candidate for a close supermassive black hole (SMBH) binary, but also because of the thermal br…