2021/09/16 by Gopal Bhatta · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Blazar #Dark Matter and Cosmic Phenomena #Flux (metallurgy) #Gamma ray #Light curve #Observatory #Physics #Quasiperiodic function #Radio Astronomy Observations and Technology #Telescope #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/ac2819
25 pages, 7 Figures, ApJ accepted
arxiv created 2021/09/16 · openalex publication_date 2021/09/16 · arxiv updated 2021/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Optical observations of a sample of 12 γ-ray bright blazars from four optical data archives, AAVSO, SMARTS, Catalina, and Steward Observatory, are compiled to create densely sampled light curves spanning more than a decade. As a part of the blazar multi-wavelength studies, several methods of analyses, e. g., flux distribution and RMS-flux relation, are performed on the observations with an aim to compare the results with the similar ones in the \gama-ray band presented in Bhatta & Dhital 2020. It is found that, similar to γ-ray band, blazars display significant variability in the optical band that can be characterized with log-normal flux distribution and a power-law dependence of RMS on flux. It could be an indication of possible inherent linear RMS-flux relation, yet the scatter in the data does not allow to rule out other possibilities. When comparing variability properties in the two bands, the blazars in the \gama-rays are found to exhibit stronger variability with steeper possible linear RMS-flux relation and the flux distribution that is more skewed towards higher fluxes. The cross-correlation study shows that except for the source 3C 273, the overall optical and the γ-ray emission in the sources are highly correlated, suggesting a co-spatial existence of the particles responsible for both the optical and γ-ray emission. Moreover, the sources S5 0716+714, Mrk 421, Mrk 501, PKS 1424-418 and PKS 2155-304 revealed possible evidence for quasi-periodic oscillations in the optical emission with the characteristic timescales, which are comparable to those in the γ-ray band detected in our previous work.