Abstract:
We report the first results obtained from our campaign to characterize the intra-night-optical variability (INOV)
properties of Fermi detected blazars, using the observations from the recently commissioned 1.3 m J. C.
Bhattacharya telescope (JCBT). During the first run, we were able to observe 17 blazars in the Bessel R filter for
∼137 hr. Using C- and scaled F-statistics, we quantify the extent of INOV and derive the duty cycle (DC), which is
the fraction of time during which a source exhibits a substantial flux variability. We find a high DC of 40% for BL
Lac objects and the flat spectrum radio quasars are relatively less variable (DC ∼ 15%). However, when estimated
for blazars sub-classes, a high DC of ∼59% is found in low synchrotron peaked (LSP) blazars, whereas,
intermediate and high synchrotron peaked objects have a low DC of ∼11% and 13%, respectively. We find
evidence of the association of the high amplitude INOV with the γ-ray flaring state. We also notice a high
polarization during the elevated INOV states (for the sources that have polarimetric data available), thus supporting
the jet based origin of the observed variability. We plan to enlarge the sample and utilize the time availability from
the small telescopes, such as 1.3 m JCBT, to strengthen/verify the results obtained in this work and those existing
in the literature.
