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相关论文: Further evidence for intra-night optical variabili…

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We present the results of a comparative study of the intra-night optical variability (INOV) characteristics of radio-loud and radio-quiet quasars, which involves a systematic intra-night optical monitoring of seven sets of high luminosity…

天体物理学 · 物理学 2009-11-10 C. S. Stalin , Gopal-Krishna , Ram Sagar , Paul J. Wiita

We present results of a programme of multi-epoch, intra-night optical monitoring of a sample of non-blazar type AGN, which includes seven radio-quiet QSOs (RQQs) and an equal number of radio-loud, lobe-dominated quasars (LDQs), covering a…

天体物理学 · 物理学 2009-11-10 C. S. Stalin , Gopal-Krishna , Ram Sagar , Paul J. Wiita

We report an extension of our program to search for radio-quiet BL Lac candidates using intra-night optical variability (INOV) as a probe. The present INOV observations cover a well-defined representative set of 10 `radio-quiet…

高能天体物理现象 · 物理学 2016-07-27 Parveen Kumar , Hum Chand , Gopal-Krishna

This is continuation of our programme to search for the elusive radio-quiet BL Lacs, by carrying out a systematic search for intranight optical variability (INOV) in a subset of `weak-line quasars' which are already designated as…

高能天体物理现象 · 物理学 2015-06-23 Parveen Kumar , Gopal-Krishna , Hum Chand

We report the results of our intensive intranight optical monitoring of 8 `radio-intermediate quasars' (RIQs) having flat or inverted radio spectra. The monitoring was carried out in {\it R-} band on 25 nights during 2005-09. An intranight…

宇宙学与河外天体物理 · 物理学 2015-05-14 Arti Goyal , Gopal-Krishna , S. Joshi , R. Sagar , Paul J. Wiita , G. C. Anupama , D. K. Sahu

This is continuation of our search for the elusive radio-quiet blazars, by carrying out a systematic programme to detect intranight optical variability (INOV) in a subset of `Weak-Lines-Quasars' (WLQs) which are designated as `high…

高能天体物理现象 · 物理学 2015-06-19 Hum Chand , Parveen Kumar , Gopal-Krishna

Based on a recently started programme, we report the first search for intranight optical variability among radio-quiet weak-line-quasars (RQWLQs). Eight members of this class were observed on 13 nights in the R-band, such that each source…

宇宙学与河外天体物理 · 物理学 2020-04-08 Gopal-Krishna , Ravi Joshi , Hum Chand

We report optical monitoring observations of 20 high-luminosity AGN, 12 of which are radio-quiet quasars (RQQs). Intra-night optical variability (INOV) was detected for 13 of the 20 objects, including 5 RQQs. The variations are distinctly…

天体物理学 · 物理学 2009-11-10 C. S. Stalin , A. C. Gupta , Gopal-Krishna , P. J. Wiita , R. Sagar

We present results of a multi-epoch intra-night optical monitoring of eleven blazars consisting of six BL Lac objects and five radio core-dominated quasars (CDQs). These densely sampled and sensitive R-band CCD observations, carried out…

天体物理学 · 物理学 2009-11-10 Ram Sagar , C. S. Stalin , Gopal-Krishna , Paul J. Wiita

We present the results of an optical photometric monitoring program of 10 extremely radio loud broad absorption line quasars (RL-BALQSOs) with radio-loudness parameter, R, greater than 100 and magnitude g_i < 19. Over an observing run of…

高能天体物理现象 · 物理学 2015-06-12 Ravi Joshi , Hum Chand

We present new clues to the problem of the radio loudness dichotomy arising from an extensive search for intranight optical variability in seven sets of optically luminous radio-quiet quasars and (radio-loud) BL Lacertae objects, which are…

天体物理学 · 物理学 2009-11-07 Gopal-Krishna , C. S. Stalin , Ram Sagar , Paul J. Wiita

{Abridged} Rapid variations in optical flux are seen in many quasars and all blazars. The amount of variability in different classes of Active Galactic Nuclei has been studied extensively but many questions remain unanswered. We present the…

高能天体物理现象 · 物理学 2015-06-05 Arti Goyal , Gopal-Krishna , Paul J. Wiita , G. C. Anupama , D. K. Sahu , R. Sagar , S. Joshi

We explore the potential of the ongoing Zwicky-Transient-Facility (ZTF) survey for studying Intra-Night Optical Variability (INOV) of active galactic nuclei (AGN), in particular for picking rare events of large INOV amplitudes, whose…

星系天体物理 · 物理学 2023-05-03 Vibhore Negi , Gopal-Krishna , Ravi Joshi , Hum Chand , Paul Wiita , Navaneeth P K , Ravi S. Singh

The incidence of intra-night optical variability (INOV) is known to to differ significantly among different classes of powerful active galactic nuclei (AGN). A number of statistical methods have been employed in the literature for testing…

高能天体物理现象 · 物理学 2015-06-16 Arti Goyal , Gopal-Krishna , Paul J. Wiita , C. S. Stalin , Ram Sagar

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 from a radio-quiet to radio-loud state, on a decadal time…

高能天体物理现象 · 物理学 2024-12-18 Krishan Chand , Gopal-Krishna , Hum Chand

For a new sample of 8 weak-line-quasars (WLQs) we report a sensitive search in 20 intranight monitoring sessions, for blazar-like optical flux variations on hour-like and longer time scale (day/month/year$-$like). The sample consists…

高能天体物理现象 · 物理学 2017-09-20 P. Kumar , Gopal-Krishna , C. S. Stalin , H. Chand , R. Srianand , P. Petitjean

This overview provides a historical perspective highlighting the pioneering role which the fairly modest observational facilities of ARIES have played since the 1990s in systematically characterizing the optical variability on hour-like…

星系天体物理 · 物理学 2017-11-16 Gopal-Krishna , Paul J. Wiita

We present the result of our extensive intranight optical monitoring of the well known low-energy peaked BL Lac (LBL) object PKS 0735+178. This long-term follow-up consists of $R$-band monitoring for a minimum duration of $\sim 4$ hours, on…

宇宙学与河外天体物理 · 物理学 2015-05-13 Arti Goyal , Gopal-Krishna , G. C. Anupama , D. K. Sahu , R. Sagar , S. Britzen , M. Karouzos , M. F. Aller , H. D. Aller

In the present paper we report the detection of intra-night variability in some of the RQQSOs and one LDQ. To study intra-night variability, we carried out photometric monitoring of seven RQQSOs and one LDQ in Johnson V-passband using 1.2…

天体物理学 · 物理学 2007-05-23 A. C. Gupta , U. C. Joshi

In this first systematic attempt to characterise the intranight optical variability (INOV) of TeV detected blazars, we have monitored a well defined set of 9 TeV blazars on total 26 nights during 2004-2010. In this R (or V)-band monitoring…

宇宙学与河外天体物理 · 物理学 2015-05-28 Gopal-Krishna , Arti Goyal , S. Joshi , Chrisphin Karthick , R. Sagar , Paul J. Wiita , G. C. Anupama , D. K. Sahu
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