English

Optical intra-day variability of the blazar S5 0716+714

High Energy Astrophysical Phenomena 2023-11-20 v1

Abstract

We present an extensive recent multi-band optical photometric observations of the blazar S5 0716+714 carried out over 53 nights with two telescopes in India, two in Bulgaria, one in Serbia, and one in Egypt during 2019 November -- 2022 December. We collected 1401, 689, 14726, and 165 photometric image frames in B, V, R, and I bands, respectively. We montiored the blazar quasi-simultaneously during 3 nights in B, V, R, and I bands; 4 nights in B, V, and R; 2 nights in V, R, and I; 5 nights in B and R; and 2 nights in V and R bands. We also took 37 nights of data only in R band. Single band data are used to study intraday flux variability and two or more bands quasi-simultaneous observations allow us to search for colour variation in the source. We employ the power-enhanced F-test and the nested ANOVA test to search for genuine flux and color variations in the light curves of the blazar on intraday timescales. Out of 12, 11, 53, and 5 nights observations, intraday variations with amplitudes between ~3% and ~20% are detected in 9, 8, 31 and 3 nights in B, V, R, and I bands, respectively, corresponding to duty cycles of 75%, 73%, 58% and 60%. These duty cycles are lower than those typically measured at earlier times. On these timescales color variations with both bluer-when-brighter and redder-when-brighter are seen, though nights with no measurable colour variation are also present. We briefly discuss possible explanations for this observed intraday variability.

Keywords

Cite

@article{arxiv.2311.10358,
  title  = {Optical intra-day variability of the blazar S5 0716+714},
  author = {Tushar Tripathi and Alok C. Gupta and Ali Takey and Rumen Bachev and Oliver Vince and Anton Strigachev and Pankaj Kushwaha and E. G. Elhosseiny and Paul J. Wiita and G. Damljanovic and Vinit Dhiman and A. Fouad and Haritma Gaur and Minfeng Gu and G. E. Hamed and Shubham Kishore and A. Kurtenkov and Shantanu Rastogi and E. Semkov and I. Zead and Zhongli Zhang},
  journal= {arXiv preprint arXiv:2311.10358},
  year   = {2023}
}

Comments

19 pages, 5 figures, 4 tables, Accepted for Publication in MNRAS