TY - JOUR
T1 - Multiband optical variability of the TeV blazar PG 1553 + 113 in 2019
AU - Dhiman, Vinit
AU - Gupta, Alok C.
AU - Kurtanidze, Sofia O.
AU - Eglītis, Ilgmārs
AU - Strigachev, A.
AU - Damljanovic, G.
AU - Wiita, Paul J.
AU - Gu, Minfeng
AU - Gaur, Haritma
AU - Vince, Oliver
AU - Bachev, R.
AU - Bisen, D. P.
AU - Ibryamov, S.
AU - Ivanidze, R. Z.
AU - Jovanovic, Miljana D.
AU - Kurtanidze, Omar M.
AU - Nikolashvili, M. G.
AU - Semkov, E.
AU - Spassov, B.
AU - Stojanovic, M.
AU - Villarroel, Beatriz
AU - Xu, Haiguang
AU - Zhang, Zhongli
N1 - Publisher Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - We report the flux and spectral variability of PG 1553 + 113 on intra-night (IDV) to short-term time-scales using BVRI data collected over 91 nights from 28 February to 8 November 2019 employing 10 optical telescopes: three in Bulgaria, two each in India and Serbia, and one each in Greece, Georgia, and Latvia. We monitored the blazar quasi-simultaneously for 16 nights in the V and R bands and 8 nights in the V, R, I bands and examined the light curves (LCs) for intra-day flux and colour variations using two powerful tests: the power-enhanced F-test and the nested ANOVA test. The source was found to be significantly (>99 per cent) variable in 4 nights out of 27 in R-band, 1 out of 16 in V-band, and 1 out of 6 nights in I-band. No temporal variations in the colours were observed on IDV time-scale. During the course of these observations the total variation in R-band was 0.89 mag observed. We also investigated the spectral energy distribution (SED) using B-, V-, R-, and I-band data. We found optical spectral indices in the range of 0.878 ± 0.029 to 1.106 ± 0.065 by fitting a power law (Fν∝ν−α) to these SEDs of PG 1553 + 113. We found that the source follows a bluer-when-brighter trend on IDV time-scales. We discuss possible physical causes of the observed spectral variability.
AB - We report the flux and spectral variability of PG 1553 + 113 on intra-night (IDV) to short-term time-scales using BVRI data collected over 91 nights from 28 February to 8 November 2019 employing 10 optical telescopes: three in Bulgaria, two each in India and Serbia, and one each in Greece, Georgia, and Latvia. We monitored the blazar quasi-simultaneously for 16 nights in the V and R bands and 8 nights in the V, R, I bands and examined the light curves (LCs) for intra-day flux and colour variations using two powerful tests: the power-enhanced F-test and the nested ANOVA test. The source was found to be significantly (>99 per cent) variable in 4 nights out of 27 in R-band, 1 out of 16 in V-band, and 1 out of 6 nights in I-band. No temporal variations in the colours were observed on IDV time-scale. During the course of these observations the total variation in R-band was 0.89 mag observed. We also investigated the spectral energy distribution (SED) using B-, V-, R-, and I-band data. We found optical spectral indices in the range of 0.878 ± 0.029 to 1.106 ± 0.065 by fitting a power law (Fν∝ν−α) to these SEDs of PG 1553 + 113. We found that the source follows a bluer-when-brighter trend on IDV time-scales. We discuss possible physical causes of the observed spectral variability.
KW - quasars: individual
KW - galaxies: active
KW - BL Lacertae objects: individual: PG 1553 + 113
KW - BL Lacertae objects: general
UR - https://academic.oup.com/mnras/article/519/2/2796/6948336
UR - https://www.scopus.com/pages/publications/85159190954
U2 - 10.1093/mnras/stac3709
DO - 10.1093/mnras/stac3709
M3 - Article
SN - 0035-8711
VL - 519
SP - 2796
EP - 2811
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -