14 citations · 29 across the 10 of their papers we have counts for
12 papers
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…
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…
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…
The transience and persistence of high optical polarization state in beamed radio quasars
Krishan Chand, Gopal-Krishna, Amitesh Omar +2
We examine the long-term stability (on decade-like time scales) of optical `high polarization' (HP) state with , which commonly occurs in flat-spectrum (i.e., beam…
Intranight optical variability of low-mass Active Galactic Nuclei: A Pointer to blazar-like activity
Gopal-Krishna, Krishan Chand, Hum Chand +4
This study aims to characterise, for the first time, intranight optical variability (INOV) of low-mass active galactic nuclei (LMAGN) which host a black hole (BH) of mass $M_{BH} \…
Persistence of blazar state in flat-spectrum radio quasars
Krishan Chand, Gopal-Krishna
Flat-spectrum radio quasars (FSRQs) whose brightness is dominated by a relativistically beamed core, are frequently found in 'blazar state' commonly inferred from a high optical po…
Pluto's atmosphere in plateau phase since 2015 from a stellar occultation at Devasthal
Bruno Sicardy, Nagarhalli M. Ashok, Anandmayee Tej +13
A stellar occultation by Pluto was observed on 6 June 2020 with the 1.3-m and 3.6-m telescopes located at Devasthal, Nainital, India, using imaging systems in the I and H bands, re…
Intranight variability of UV emission from powerful blazars
Krishan Chand, Gopal-Krishna, Amitesh Omar +4
We report the first study to characterise intranight variability of the blazar class from the perspective of (rest-frame) UV emission. For this, we carried out intranight optical m…
DXML: Distributed Extreme Multilabel Classification
Pawan Kumar
As a big data application, extreme multilabel classification has emerged as an important research topic with applications in ranking and recommendation of products and items. A sca…
A Search for Blazar Activity in Broad-Absorption-Line Quasars
Sapna Mishra, Gopal-Krishna, Hum Chand +3
Our recently reported lack of Intra-Night Optical Variability (INOV) among Broad-Absorption-Line (BAL) quasars exhibiting some blazar-like radio properties, either questions polar…
Are there broad absorption-line blazars?
Sapna Mishra, Gopal-Krishna, Hum Chand +2
We report the first systematic search for blazars among broad-absorption-line (BAL) quasars. This is based on our intranight optical monitoring of a well-defined sample of 10 candi…
Optical detection of a GMRT-detected candidate high-redshift radio galaxy with 3.6-m Devasthal optical telescope
A. Omar, A. Saxena, K. Chand +6
We report optical observations of TGSS J1054+5832, a candidate high-redshift () steep-spectrum radio galaxy, in and bands using the faint object spectrograph and…