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Related papers: Multi wavelength study of 4C+28.07

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The active galactic nucleus 4C +28.07 is a flat spectrum radio quasar, one of the brightest at $\gamma$-ray energies. We study its multi-wavelength emission by analysing $\sim12.3$ years of \textit{Fermi-LAT} data in the $\gamma$-ray band…

High Energy Astrophysical Phenomena · Physics 2022-01-10 Davit Zargaryan , Jonathan Mackey , Thibault Barnouin , Felix Aharonian

Recently, blazar 4C +27.50 was found to be flaring in gamma-rays since its detection with Fermi-LAT in 2008. For the first time, a dedicated temporal and spectral study of the blazar 4C +27.50 has been performed in this work to understand…

High Energy Astrophysical Phenomena · Physics 2025-04-29 Joysankar Majumdar , Sakshi Maurya , Raj Prince

We present 14.5-year multi-wavelength analysis of flat-spectrum radio quasar B2 1348+30B using Swift-UVOT, Swift-XRT, and Fermi-LAT observations. In the gamma-ray band, the 3 day bin lightcurve reveals two major flaring events on 2010-09-19…

High Energy Astrophysical Phenomena · Physics 2025-06-04 Sajad Ahanger , Sunder Sahayanathan , Sitha K. Jagan , Shah Zahir , Naseer Iqbal

3C 454.3 is frequently observed in flaring state. The long term light curve of this source has been analysed with 9 year (August 2008 - July 2017) data from Fermi LAT detector. We have identified five flares and one quiescent state. The…

High Energy Astrophysical Phenomena · Physics 2020-05-06 Avik Kumar Das , Raj Prince , Nayantara Gupta

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…

High Energy Astrophysical Phenomena · Physics 2022-06-22 Malik Zahoor , Shah Zahir , Sunder Sahayanathan , Naseer Iqbal , Aaqib Manzoor

The results of a long-term multiwavelength study of the powerful flat spectrum radio quasar 3C 454.3 using {\it Fermi}-LAT and Swift XRT/UVOT data are reported. In the $\gamma$-ray band, {\it Fermi}-LAT observations show several major…

High Energy Astrophysical Phenomena · Physics 2021-04-28 N. Sahakyan

This paper presents the gamma-ray spectral and timing results from the long-term regular observations of Mrk 421 with the Large Area Telescope (LAT) onboard Fermi during 2008 August - 2023 August. We discerned six periods the relatively…

High Energy Astrophysical Phenomena · Physics 2025-03-05 B. Kapanadze , A. Gurchumelia , M. Aller

The FSRQ 4C+01.28 is a bright and highly variable radio and $\gamma$-ray emitter. We aim to pinpoint the location of the $\gamma$-ray emitting region within its jet in order to derive strong constraints on $\gamma$-ray emission models for…

High Energy Astrophysical Phenomena · Physics 2026-01-14 F. Rösch , M. Kadler , E. Ros , L. Ricci , M. A. Gurwell , T. Hovatta , N. R. MacDonald , A. C. S. Readhead

We investigate the $\gamma$-ray and X-ray properties of the flat spectrum radio quasar (FSRQ) \4c50 at redshift $z= 1.517$. The {\it Fermi} Large Area Telescope (LAT) data indicate that this source was in an active state since 2013 July.…

High Energy Astrophysical Phenomena · Physics 2021-06-03 Jianeng Zhou , V. Jithesh , Chen Liang , Zhongxiang Wang

As one of the most active blazars, Mrk421 is an excellent candidate for the study of the physical processes within the jets of AGN. Here we report on the extensive multi-wavelength observations of Mrk 421 over 4.5 years, from 2008 August to…

High Energy Astrophysical Phenomena · Physics 2015-10-08 Songzhan Chen , Silvia Vernetto

We present a multi-wavelength study of the FSRQ CTA 102 using Fermi-LAT and simultaneous Swift-XRT/UVOT observations. The Fermi-LAT telescope detected one of the brightest flares from this object during Sep, 2016 to Mar, 2017. In the 190…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Raj Prince , Gayathri Raman , Joachim Hahn , Nayantara Gupta , Pratik Majumdar

The flat spectrum radio quasar 3C 279 was observed in an extremely high activity state on June 16, 2015 (MJD 57189). In this paper, we investigate the properties of this flaring episode in the high energy $\gamma$-ray and optical bands…

High Energy Astrophysical Phenomena · Physics 2020-03-05 K K Singh , P J Meintjes , B Bisschoff , F A Ramamonjisoa , B van Soelen

High redshift blazars are among the most powerful non-explosive sources in the Universe and play a crucial role in understanding the evolution of relativistic jets. To understand these bright objects, we performed a detailed investigation…

High Energy Astrophysical Phenomena · Physics 2024-01-29 N. Sahakyan , G. Harutyunyan , S. Gasparyan , D. Israyelyan

We report the results of our long-term multiwavelength spectral energy distribution (SED) study on the flat spectrum radio quasar 3C 279 during the $\sim14$ years (2008--2022) of {\sl Fermi}-LAT (Large Area Telescope) observing period. The…

The blazar 4C 31.03 recently underwent a major gamma-ray outburst at the beginning of 2023 after a prolonged quiescent phase. Fermi-LAT reported a daily average flux of 5x10^-6 phs cm^-2 s^-1, which is about 60 times its average value. We…

High Energy Astrophysical Phenomena · Physics 2024-04-16 Aminabi Thekkoth , Baheeja C , S Sahayanathan , C D Ravikumar

The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) gamma-ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy…

High Energy Astrophysical Phenomena · Physics 2015-06-19 M. Ackermann , M. Ajello , A. Allafort , E. Antolini , G. Barbiellini , D. Bastieri , R. Bellazzini , E. Bissaldi , E. Bonamente , J. Bregeon , M. Brigida , P. Bruel , R. Buehler , S. Buson , G. A. Caliandro , R. A. Cameron , P. A. Caraveo , E. Cavazzuti , C. Cecchi , R. C. G. Chaves , A. Chekhtman , J. Chiang , G. Chiaro , S. Ciprini , R. Claus , J. Cohen-Tanugi , J. Conrad , S. Cutini , F. D'Ammando , F. de Palma , C. D. Dermer , E. do Couto e Silva , D. Donato , P. S. Drell , C. Favuzzi , J. Finke , W. B. Focke , A. Franckowiak , Y. Fukazawa , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , N. Giglietto , F. Giordano , M. Giroletti , G. Godfrey , I. A. Grenier , S. Guiriec , M. Hayashida , J. W. Hewitt , D. Horan , R. E. Hughes , G. Iafrate , A. S. Johnson , J. Knodlseder , M. Kuss , J. Lande , S. Larsson , L. Latronico , F. Longo , F. Loparco , M. N. Lovellette , P. Lubrano , M. Mayer , M. N. Mazziotta , J. E. McEnery , P. F. Michelson , T. Mizuno , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , R. Nemmen , E. Nuss , T. Ohsugi , M. Orienti , E. Orlando , J. S. Perkins , M. Pesce-Rollins , F. Piron , G. Pivato , T. A. Porter , S. Rainò , M. Razzano , A. Reimer , O. Reimer , D. A. Sanchez , A. Schulz , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , L. Stawarz , H. Takahashi , T. Takahashi , J. G. Thayer , J. B. Thayer , D. J. Thompson , M. Tinivella , D. F. Torres , G. Tosti , E. Troja , T. L. Usher , J. Vandenbroucke , V. Vasileiou , G. Vianello , V. Vitale , M. Werner , B. L. Winer , D. L. Wood , K. S. Wood , J. Aleksic , S. Ansoldi , L. A. Antonelli , P. Antoranz , A. Babic , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra Gonzalez , W. Bednarek , K. Berger , E. Bernardini , A. Biland , O. Blanch , R. K. Bock , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , E. Carmona , A. Carosi , D. Carreto Fidalgo , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , P. Da Vela , F. Dazzi , A. De Angelis , G. De Caneva , B. De Lotto , C. Delgado Mendez , M. Doert , A. Dominguez , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher , D. Elsaesser , E. Farina , D. Ferenc , M. V. Fonseca , L. Font , K. Frantzen , C. Fruck , R. J. Garcia Lopez , M. Garczarczyk , D. Garrido Terrats , M. Gaug , G. Giavitto , N. Godinovic , A. Gonzalez Munoz , S. R. Gozzini , D. Hadasch , A. Herrero , D. Hildebrand , J. Hose , D. Hrupec , W. Idec , V. Kadenius , H. Kellermann , M. L. Knoetig , K. Kodani , Y. Konno , J. Krause , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , N. Lewandowska , E. Lindfors , S. Lombardi , M. Lopez , R. Lopez-Coto , A. Lopez-Oramas , E. Lorenz , I. Lozano , M. Makariev , K. Mallot , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martinez , D. Mazin , U. Menzel , M. Meucci , J. M. Miranda , R. Mirzoyan , A. Moralejo , P. Munar-Adrover , D. Nakajima , A. Niedzwiecki , K. Nishijima , K. Nilsson , N. Nowak , R. Orito , A. Overkemping , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , S. Partini , M. Persic , F. Prada , P. G. Prada Moroni , E. Prandini , S. Preziuso , I. Puljak , R. Reinthal , W. Rhode , M. Ribo , J. Rico , J. Rodriguez Garcia , S. Rugamer , A. Saggion , T. Saito , K. Saito , M. Salvati , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpaa , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , V. Stamatescu , A. Stamerra , T. Steinbring , J. Storz , S. Sun , T. Suric , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzic , D. Tescaro , M. Teshima , J. Thaele , O. Tibolla , T. Toyama , A. Treves , P. Vogler , R. M. Wagner , F. Zandanel , R. Zanin , M. F. Aller , E. Angelakis , D. A. Blinov , S. G. Djorgovski , A. J. Drake , N. V. Efimova , M. A. Gurwell , D. C. Homan , B. Jordan , E. N. Kopatskaya , Y. Y. Kovalev , O. M. Kurtanidze , A. Lahteenmaki , V. M. Larionov , M. L. Lister , E. Nieppola , M. G. Nikolashvili , E. Ros , T. Savolainen , L. A. Sigua , M. Tornikoski , .

A multiwavelength temporal and spectral analysis of flares of 3C 279 during November 2017--July 2018 are presented in this work. Three bright gamma-ray flares were observed simultaneously in X-ray and Optical/UV along with a prolonged…

High Energy Astrophysical Phenomena · Physics 2020-03-04 Raj Prince

The flat-spectrum radio quasar 3C~454.3 throughout the years has presented very high activity phases (flares) in which the different wavebands increase their flux dramatically. In this work, we perform multiwavelength analysis from radio to…

High Energy Astrophysical Phenomena · Physics 2021-01-06 Raúl Antonio Amaya-Almazán , Vahram Chavushyan , Victor Manuel Patiño-Álvarez

Determining the location of $\gamma$-ray emission in blazar jets is a challenging task. Pinpointing the exact location of $\gamma$-ray production within a relativistic jet can place strong constraints on our understanding of high-energy…

High Energy Astrophysical Phenomena · Physics 2021-12-20 F. Rösch , M. Kadler , E. Ros , M. Gurwell , T. Hovatta , M. Kreter , N. R. MacDonald , A. C. S. Readhead
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