Temporal correlation between the optical and ? -ray flux variations in the blazar 3C 454.3
- Title
- Temporal correlation between the optical and ? -ray flux variations in the blazar 3C 454.3
- Creator
- Rajput B.; Stalin C.S.; Sahayanathan S.; Rakshit S.; Mandal A.K.
- Description
- Blazars show optical and ? -ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data at optical, ultraviolet, X-ray, and ? -ray energies, spanning about 9 yr from 2008 August to 2017 February.We have identified four time intervals (epochs), A, B, D, and E, when the source showed large-amplitude optical flares. In epochs A and B the optical and ? -ray flares are correlated, while in D and E corresponding flares in ? -rays are weak or absent. In epoch B the degree of optical polarization strongly correlates with changes in optical flux during a short-duration optical flare superimposed on one of long duration. In epoch E the optical flux and degree of polarization are anticorrelated during both the rising and declining phases of the optical flare. We carried out broad-band spectral energy distribution (SED) modelling of the source for the flaring epochs A,B, D, and E, and a quiescent epoch, C. Our SED modelling indicates that optical flares with absent or weak corresponding ? -ray flares in epochs D and E could arise from changes in a combination of parameters, such as the bulk Lorentz factor, magnetic field, and electron energy density, or be due to changes in the location of the ? -ray-emitting regions. 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
- Source
- Monthly Notices of the Royal Astronomical Society, Vol-486, No. 2, pp. 1781-1795.
- Date
- 2019-01-01
- Publisher
- Oxford University Press
- Subject
- galaxies: active; galaxies: jets; galaxies: nuclei; gamma-rays: galaxies; quasars: individual: 3C 454.3; X-rays: galaxies.
- Coverage
- Rajput B., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560034, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560034, India; Sahayanathan S., Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Rakshit S., Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Quantum, Vesilinnantie 5, Turku, FI-20014, Finland, Astrophysical-Sciences-Division, Bhabha Atomic Research-Centre, Mumbai, 400085, India; Mandal A.K., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560034, India, Department of Physics, CHRIST (Deemed to Be University), Hosur Road, Bangalore, 560029, India
- Rights
- All Open Access; Green Open Access
- Relation
- ISSN: 358711; CODEN: MNRAA
- Format
- Online
- Language
- English
- Type
- Article
Collection
Citation
Rajput B.; Stalin C.S.; Sahayanathan S.; Rakshit S.; Mandal A.K., “Temporal correlation between the optical and ? -ray flux variations in the blazar 3C 454.3,” CHRIST (Deemed To Be University) Institutional Repository, accessed February 24, 2025, https://archives.christuniversity.in/items/show/16727.