IIA Institutional Repository

Browsing IIAP Publications by Author "Sahayanathan, S"

Browsing IIAP Publications by Author "Sahayanathan, S"

Sort by: Order: Results:

  • Awakening of the high-redshift blazar CGRaBS J0809+5341 
    Paliya, Vaidehi S; Parker, M. L; Stalin, C. S; Fabian, A. C; Ramya, S; Covino, S; Tagliaferri, G; Sahayanathan, S; Ravikumar, C. D (IOP Publishing, 2015-04)
    CGRaBS J0809+5341, a high-redshift blazar at z = 2.144, underwent a giant optical outburst on 2014 April 19 when it brightened by ~5 mag and reached an unfiltered apparent magnitude of 15.7 mag. This implies an absolute ...
  • Correlation between optical and γ -ray flux variations in bright flat spectrum radio quasars 
    Rajput, Bhoomika; Stalin, C. S; Sahayanathan, S (Oxford University Press on behalf of the Royal Astronomical Society, 2020-11)
    Blazars are known to show flux variations over a range of energies from low-energy radio to high-energy γ-rays. Cross-correlation analysis of the optical and γ-ray light curves in blazars shows that flux variations are ...
  • Correlation between optical and γ-ray flux variations in BL Lacs 
    Rajput, Bhoomika; Shah, Zahir; Stalin, C. S; Sahayanathan, S; Rakshit, S (Oxford University Press on behalf of the Royal Astronomical Society, 2021-06)
    We report here results of the analysis of correlated flux variations between the optical and GeV γ-ray bands in three bright BL Lac objects, namely AO 0235+164, OJ 287, and PKS 2155−304. This was based on the analysis of ...
  • Multi-wavelength observations of 3C 279 during the extremely bright gamma-ray flare in 2014 March-April 
    Paliya, Vaidehi S; Sahayanathan, S; Stalin, C. S (IOP Publishing, 2015-04)
    The well-studied blazar 3C 279 underwent a giant γ-ray outburst in 2014 March–April. The measured γ-ray flux is the highest detected from 3C 279 by the Fermi Large Area Telescope. Hour scale γ-ray flux variability is ...
  • Multiwavelength spectral modelling of the candidate neutrino blazar PKS 0735+178 
    Bharathan, Athira M; Stalin, C. S; Sahayanathan, S; Bhattacharyya, Subir; Mathew, Blesson (Oxford University Press on behalf of Royal Astronomical Society, 2024-04)
    The BL Lac object PKS 0735+178 was in its historic γ-ray brightness state during 2021 December. This period also coincides with the detection of a neutrino event IC 211208A, which was localized close to the vicinity of PKS ...
  • The Nature of γ -ray loud Narrow-line Seyfert I Galaxies PKS 1502+036 And PKS 2004-447 
    Paliya, Vaidehi S; Stalin, C. S; Shukla, A; Sahayanathan, S (IOP Publishing, 2013-05-01)
    Variable γ-ray emission has been discovered in five radio-loud narrow-line Seyfert 1 (NLSy1) galaxies by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. This has clearly demonstrated that these NLSy1 ...
  • On the Spectral Curvature of VHE Blazar 1ES 1011 + 496: Effect of Spatial Particle Diffusion 
    Sinha, A; Sahayanathan, S; Acharya, B. S; Anupama, G. C; Chitnis, V. R; Singh, B. B (IOP Publishing, 2017-02-10)
    The American Astronomical Society, find out more The Institute of Physics, find out more On the Spectral Curvature of VHE Blazar 1ES 1011+496: Effect of Spatial Particle Diffusion Atreyee Sinha1, S. ...
  • The peculiar radio-loud narrow line seyfert 1 galaxy 1H 0323+342 
    Paliya, Vaidehi S; Sahayanathan, S; Parker, M. L; Fabian, A. C; Stalin, C. S; Anjum, A; Pandey, S. B (IOP Publishing, 2014-07-10)
    We present a multi-wavelength study of the radio-loud narrow line Seyfert 1 galaxy (NLSy1), 1H 0323+342, detected by Fermi Gamma Ray Space Telescope. Multi-band light curves show many orphan X-ray and optical flares having ...
  • Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3 
    Rajput, Bhoomika; Stalin, C. S; Sahayanathan, S; Rakshit, S; Amit Kumar Mandal (Oxford University Press on behalf of the Royal Astronomical Society, 2019-06)
    Blazars show optical and γ-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 ...
  • The violent hard X-ray variability of MRK 421 observed by Nustar in 2013 April 
    Paliya, Vaidehi S; Bottcher, M; Diltz, C; Stalin, C. S; Sahayanathan, S; Ravikumar, C. D (IOP Publishing, 2015-10-01)
    The well-studied blazar Markarian 421 (Mrk 421, z = 0.031) was the subject of an intensive multi-wavelength campaign when it flared in 2013 April. The recorded X-ray and very high-energy (E > 100 GeV) γ-ray fluxes are the ...

Search DSpace


Browse

My Account