Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Sunder Sahayanathan"'
Autor:
Soumya Gupta, Sunder Sahayanathan
Publikováno v:
The Astrophysical Journal Letters, Vol 970, Iss 1, p L12 (2024)
The spectral properties of a composite thermal emission arising from a relativistic expanding fireball can be remarkably different from the Planck function. We perform a detailed study of such a system to explore the features of the prompt emission s
Externí odkaz:
https://doaj.org/article/c7d2e1b555e14966966e907ba684865b
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 511:994-1003
The very-high-energy (VHE) gamma-ray spectral indices of blazars show a strong correlation with the source redshift. The absence of any such correlation in low-energy gamma-rays and X-rays indicates the presence of extragalactic background light (EBL
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4500fa7ba1b8784077e8b341d98bb5de
https://doi.org/10.1093/mnras/stab3173
https://doi.org/10.1093/mnras/stab3173
We conducted a detailed long-term spectral and temporal study of flat spectrum radio quasar 4C +01.02, by using the multi-wavelength observations from Fermi-LAT, Swift-XRT, and Swift-UVOT. The $2$-day bin $\gamma$-ray lightcurve in the 2014-2017 acti
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a1c932df8b53285d70944d720d54ea8a
http://arxiv.org/abs/2206.04441
http://arxiv.org/abs/2206.04441
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 504:1772-1786
We report here results on the analysis of correlated flux variations between the optical and GeV $\gamma$-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 about 10 years of d
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9a4525e7a54fd69d6d4b3b23d7d77c48
https://doi.org/10.1093/mnras/stab970
https://doi.org/10.1093/mnras/stab970
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 504:416-427
We carried a detailed spectral and temporal study of blazar, \mbox{PKS\,0903-57} using the \emph{Fermi}-LAT and \emph{Swift}-XRT/UVOT observations, during its brightest flaring period MJD\,58931--58970. During this period, the maximum daily averaged
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::eed82c80ff471144789a656b35805de4
https://doi.org/10.1093/mnras/stab834
https://doi.org/10.1093/mnras/stab834
The attenuation of very high energy (VHE) photons by the extragalactic background light (EBL) prevents the observation of high redshift flat spectrum radio quasars (FSRQs). However, the correlation of VHE spectral index with source redshift suggests
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c827cc61e25c45c187229e925f1997b1
http://arxiv.org/abs/2204.03229
http://arxiv.org/abs/2204.03229
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 498:5128-5148
Blazars are known to show flux variations over a range of energies from low energy radio to high energy gamma-rays. Cross-correlation analysis of the optical and $\gamma$-ray light curves in blazars shows that flux variations are generally correlated
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e98c778b91943ab82005dd485dbccc6a
https://doi.org/10.1093/mnras/staa2708
https://doi.org/10.1093/mnras/staa2708
Autor:
Ranjeev Misra, Sunder Sahayanathan, N. Mankuzhiyil, Rupjyoti Gogoi, Zahoor Malik, Atreyee Sinha, Pranjupriya Goswami, Sunil Chandra
Publikováno v:
Proceedings of 37th International Cosmic Ray Conference — PoS(ICRC2021).
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::385ccc00f56ae0367588054fa6743632
https://doi.org/10.22323/1.395.0961
https://doi.org/10.22323/1.395.0961
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 486:1781-1795
Blazars show optical and $\gamma$-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, UV, X-ray
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::75abcd2386f7addd1367ce2b90d5866c
https://doi.org/10.1093/mnras/stz941
https://doi.org/10.1093/mnras/stz941
The convex (concave upward) high-energy X-ray spectra of the blazar PKS\,2155-304, observed by \emph{XMM-Newton}, is interpreted as the signature of sub-dominant inverse Compton emission. The spectra can be well fitted by a superposition of two power
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::49a0d1fbea7b37b1bb4d920628bef6c2