collaborators

6 papers

astro-ph.GA2025

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,…

astro-ph.HE2025

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…

astro-ph.GA2025

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…

astro-ph.HE2024

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…

astro-ph.HE2024

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…

astro-ph.GA2024

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…