Intranight Optical Variability of Radio-Quiet Weak Emission Line Quasars-II

Abstract

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 confidence BL Lac candidates' and are known to be radio-quiet. For 10 such RQWLQs, we present here the INOV observations taken in 16 sessions of durations > 3.5 hours each. Combining these data with our previously published INOV monitoring of RQWLQs in 13 sessions, gives a set of INOV observations of 15 RQWLQs monitored in 29 sessions each lasting more than 3.5 hours. The 29 differential light curves (DLCs), thus obtained for the 15 RQWLQs, were subjected to an statistical analysis using the F-test and the deduced INOV characteristics of the RQWLQs are compared with those published recently for several prominent AGN classes, also using the F-test. However, since the RQWLQs are generally 1-2 magnitudes fainter, a rigorous comparison has to wait for somewhat more sensitive INOV observations than those presented here. Based on our existing INOV observations, it seems that RQWLQs in our sample show a significantly higher INOV duty cycle than radio-quiet quasars and radio lobe-dominated quasars. Two sessions when we detected rather strong (blazar-like) INOV for RQWLQs are pointed out and both these RQWLQs are therefore candidates for radio-quiet BL Lacs.

arXiv comment8 pages, 2 figures and 3 tables, accepted for publication in MNRAS main journal

References in corpus (21)

• The Sloan Digital Sky Survey: Technical Summary
• The Seventh Data Release of the Sloan Digital Sky Survey
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• High-Redshift SDSS Quasars with Weak Emission Lines
• Testing tests on AGN microvariability
• Optically Selected BL Lacertae Candidates from the Sloan Digital Sky Survey Data Release Seven
• Optically identified BL Lacertae objects from the Sloan Digital Sky Survey
• A Large, Uniform Sample of X-ray Emitting AGN from the ROSAT All-Sky and Sloan Digital Sky Surveys: the Data Release 5 Sample
• Intranight optical variability of Blazars
• Clear Evidence for Intranight Optical Variability in Radio-quiet Quasars
• Intra-night Optical Variability of Luminous Radio Quiet QSOs
• Intranight optical variability of radio-quiet and radio lobe dominated quasars
• Multiwavelength Observations of Radio-quiet Quasars with Weak Emission Lines
• Optical Monitoring of Quasars: I. Variability
• Intra-night optical variability of core dominated radio quasars: the role of optical polarization
• Improved characterisation of intra-night optical variability of prominent AGN classes
• Optical microvariability properties of BALQSOs
• Highly Polarized Optically-Selected BL Lacertae Objects
• Optical variability properties of high luminosity AGN classes
• Short-term optical variability of high-redshift QSO's
• Intranight Optical Variability of Radio-Quiet Weak Emission Line Quasars

Cited by in corpus (6)

• On the reliability of microvariability tests in quasars
• Intranight Optical Variability of Radio-Quiet Weak Emission Line Quasars-III
• Intranight Optical Variability of Radio-Quiet Weak Emission Line Quasars-IV
• Evidence of under-developed torus and broad-line region of weak emission line quasars based on their spectral energy distribution
• Polarimetric and spectroscopic study of radio-quiet weak emission line quasars
• Intranight optical variability of radio-quiet BL Lacertae objects