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Related papers: Gamma-ray blazars: the view from AGILE

200 papers

Blazars, radio-loud active galactic nuclei with the relativistic jet closely aligned with the line of sight, dominate the extragalactic sky observed at gamma-ray energies, above 100 MeV. We discuss some of the emission properties of these…

High Energy Astrophysical Phenomena · Physics 2016-05-25 F. Tavecchio

The AGILE satellite discovered the transient source AGL J2241+4454 in 2010 which triggered the study of the associated field allowing for the discovery of the first Be/black hole binary system: MWC 656. This binary was suggested to be the…

High Energy Astrophysical Phenomena · Physics 2016-10-05 P. Munar-Adrover , S. Sabatini , G. Piano , M. Tavani , L. H. Nguyen , F. Lucarelli , F. Verrecchia , C. Pittori

During its first four years of scientific observations, the Fermi Large Area Telescope (Fermi-LAT) detected 3033 $\gamma$-ray sources above a 4$\sigma$ significance level. Although most of the extra-Galactic sources are active galactic…

High Energy Astrophysical Phenomena · Physics 2019-08-15 G. La Mura , G. Chiaro , S. Ciroi , P. Rafanelli , D. Salvetti , M. Berton , V. Cracco

Preliminary results of a systematic study on the simultaneous optical-to-X-rays variability in blazars are presented. Data from Swift observations of four bright gamma-ray blazars (3C 279, ON+231, S5 0716+71, PKS 2155-304) have been…

Astrophysics · Physics 2009-11-13 L. Foschini

BL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of $\gamma$-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in…

High Energy Astrophysical Phenomena · Physics 2020-04-08 E. J. Marchesini , A. Paggi , F. Massaro , N. Masetti , R. D'Abrusco , I. Andruchow , R. de Menezes

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope discovered a rapid (about 5 days duration), high-energy (E >100 MeV) gamma-ray outburst from a source identified with the blazar PKS 1502+106 (OR 103, S3 1502+10,…

High Energy Astrophysical Phenomena · Physics 2012-08-27 The Fermi LAT Collaboration , the Multifrequency Campaing Collaboration

Blazars are highly variable, radio-loud active galactic nuclei with jets oriented at a small angle to the line of sight. The observed emission of these sources covers the whole electromagnetic spectrum from radio frequencies up to the high…

High Energy Astrophysical Phenomena · Physics 2016-04-20 Alicja Wierzcholska

Blazars are the brightest and most abundant persistent sources in the extragalactic gamma-ray sky. Due to their significance, they are often observed across various energy bands to explore potential correlations between emissions at…

High Energy Astrophysical Phenomena · Physics 2024-01-22 P. Giommi , N. Sahakyan , D. Israyelyan , M. Manvelyan

High-redshift blazars are among the most powerful objects in the Universe. The spectral and temporal properties of thirty-three distant blazars ($z>2.5$) detected in the high energy $\gamma$-ray band are investigated by analyzing the {\it…

High Energy Astrophysical Phenomena · Physics 2020-08-25 N. Sahakyan , D. Israyelyan , G. Harutyunyan , M. Khachatryan , S. Gasparyan

We present an overview of the main AGILE Data Center activities and architecture. AGILE is a space mission of the Italian Space Agency (ASI) in joint collaboration with INAF, INFN, CIFS, and with the participation of several Italian space…

Instrumentation and Methods for Astrophysics · Physics 2019-11-28 Carlotta Pittori

This work investigates the multi-wavelength properties of 165 4FGL blazars from the Fermi-LAT fourth source catalogue, looking for with counterparts in the Australian SKA Pathfinder (ASKAP) First Large Absorption Survey in HI (FLASH)…

We report the results of our exploratory program carried out with the Southern Astrophysical Research (SOAR) telescope aimed at associating counterparts and establishing the nature of the Fermi Unidentified gamma-ray Sources (UGS). We…

High Energy Astrophysical Phenomena · Physics 2015-06-24 M. Landoni , F. Massaro , A. Paggi , R. D'Abrusco , D. Milisavljevic , N. Masetti , Howard. A. Smith , G. Tosti , L. Chomiuk , J. Strader , C. C. Cheung

We are leading a comprehensive multi-waveband monitoring program of 34 gamma-ray bright blazars designed to locate the emission regions of blazars from radio to gamma-ray frequencies. The "maps" are anchored by sequences of images in both…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Alan Marscher , Svetlana G. Jorstad , Valeri M. Larionov , Margo F. Aller , Anne Lahteenmaki

It has been suggested that unresolved radio galaxies and radio quasars (sometimes referred to as misaligned active galactic nuclei) could be responsible for a significant fraction of the observed diffuse gamma-ray background. In this study,…

High Energy Astrophysical Phenomena · Physics 2016-08-17 Dan Hooper , Tim Linden , Alejandro Lopez

Active Galactic Nuclei (AGN) are now known to be strong gamma-ray emitters. After briefly describing the different classes of AGN and the basic tenets of unified schemes, I discuss the role of blazars (that is BL Lacs and flat-spectrum…

Astrophysics · Physics 2007-05-23 Paolo Padovani

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

Among more than fifty blazars detected in very high energy (VHE, E>100GeV) gamma-rays, only three belong to the subclass of Flat Spectrum Radio Quasars (FSRQs). MAGIC observed FSRQ PKS 1510-089 in February-April 2012 during a high activity…

High Energy Astrophysical Phenomena · Physics 2015-06-18 MAGIC Collaboration , J. Aleksić , S. Ansoldi , L. A. Antonelli , P. Antoranz , A. Babic , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , E. Bernardini , A. Biland , O. Blanch , 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. Domínguez , 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. García López , M. Garczarczyk , D. Garrido Terrats , M. Gaug , N. Godinović , A. González Muñoz , S. R. Gozzini , D. Hadasch , M. Hayashida , J. Herrera , A. Herrero , D. Hildebrand , J. Hose , D. Hrupec , W. Idec , V. Kadenius , H. Kellermann , K. Kodani , Y. Konno , J. Krause , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , N. Lewandowska , E. Lindfors , S. Lombardi , M. López , R. López-Coto , A. López-Oramas , E. Lorenz , I. Lozano , M. Makariev , K. Mallot , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martínez , D. Mazin , U. Menzel , M. Meucci , J. M. Miranda , R. Mirzoyan , A. Moralejo , P. Munar-Adrover , D. Nakajima , A. Niedzwiecki , K. Nilsson , K. Nishijima , K. Noda , 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. Ribó , J. Rico , J. Rodriguez Garcia , S. Rügamer , A. Saggion , T. Saito , K. Saito , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , V. Stamatescu , A. Stamerra , T. Steinbring , J. Storz , M. Strzys , S. Sun , T. Surić , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , J. Thaele , O. Tibolla , D. F. Torres , T. Toyama , A. Treves , M. Uellenbeck , P. Vogler , R. M. Wagner , F. Zandanel , R. Zanin , F. Lucarelli , C. Pittori , S. Vercellone , F. Verrecchia , S. Buson , F. D'Ammando , L. Stawarz , M. Giroletti , M. Orienti , C. Mundell , I. Steele , B. Zarpudin , C. M. Raiteri , M. Villata , A. Sandrinelli , A. Lähteenäki , J. Tammi , M. Tornikoski , T. Hovatta , A. C. S. Readhead , W. Max-Moerbeck , J. L. Richards , S. Jorstad , A. Marscher , M. A. Gurwell , V. M. Larionov , D. A. Blinov , T. S. Konstantinova , E. N. Kopatskaya , L. V. Larionova , E. G. Larionova , D. A. Morozova , I. S. Troitsky , A. A. Mokrushina , Yu. V. Pavlova , W. P. Chen , H. C. Lin , N. Panwar , I. Agudo , C. Casadio , J. L. Gómez , S. N. Molina , O. M. Kurtanidze , M. G. Nikolashvili , S. O. Kurtanidze , R. A. Chigladze , J. A. Acosta-Pulido , M. I. Carnerero , A. Manilla-Robles , E. Ovcharov , V. Bozhilov , I. Metodieva , M. F. Aller , H. D. Aller , L. Fuhrmann , E. Angelakis , I. Nestoras , T. P. Krichbaum , J. A. Zensus , H. Ungerechts , A. Sievers , D. Riquelme

Active galactic nuclei (AGNs) exhibit variability across the entire electromagnetic spectrum with distinct flaring episodes at different frequencies. The high sensitivity and nearly uniform sky coverage of the Large Area Telescope on board…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Filippo D'Ammando

Of the blazars detected by EGRET in GeV gamma rays, 3C 279 is not only the best-observed by EGRET, but also one of the best-monitored at lower frequencies. We have assembled eleven spectra, from GHz radio through GeV gamma rays, from the…

Astrophysics · Physics 2009-11-06 R. C. Hartman , M. Boettcher

Blazars, a beamed population of active galactic nuclei, radiate high-energy gamma-rays, and thus are a good target for the Gamma Ray Large Area Space Telescope (GLAST). As the blazars trace the large-scale structure of the universe, one may…

Astrophysics · Physics 2008-12-18 Shin'ichiro Ando , Eiichiro Komatsu , Takuro Narumoto , Tomonori Totani