Related papers: Multi-wavelength study of Mrk 421 during a TeV fla…

Time-dependent neutrino emission from Mrk 421 during flares and predictions for IceCube

Blazars are prime candidate sources for the high energy neutrinos recently detected by IceCube. Being one of the brightest sources in the extragalactic X-ray and $\gamma$-ray sky as well as one of the nearest blazars to Earth, Mrk 421 is an…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Maria Petropoulou , Stefan Coenders , Stavros Dimitrakoudis

Search for Very High Energy Gamma Rays from an X-ray Selected Blazar Sample

In recent years, blazar surveys at radio and X-ray energies have greatly increased our understanding of this type of active galaxy. The combination of multi-wavelength data has shown that blazars follow a well defined sequence in terms of…

Astrophysics · Physics 2007-05-23 I. de la Calle Perez

Suzaku Wide Band Analysis of the X-ray Variability of TeV Blazar Mrk 421 in 2006

We present the results of X-ray observations of the well-studied TeV blazar Mrk 421 with the Suzaku satellite in 2006 April 28. During the observation, Mrk 421 was undergoing a large flare and the X-ray flux was variable, decreasing by ~ 50…

High Energy Astrophysical Phenomena · Physics 2009-07-24 Masayoshi Ushio , Takaaki Tanaka , Grzegorz Madejski , Tadayuki Takahashi , Masaaki Hayashida , Jun Kataoka , Daniel Mazin , Stefan Rügamer , Rie Sato , Masahiro Teshima , Stefan Wagner , Yuichi Yaji

Rapid X-ray Variability in Mkn 421 during a Multiwavelength Campaign

The study of short-term variability properties in AGN jets has the potential to shed light on their particle acceleration and emission mechanisms. We report results from a four-day coordinated multi-wavelength campaign on the highly-peaked…

High Energy Astrophysical Phenomena · Physics 2022-06-09 Alex G. Markowitz , Krzysztof Nalewajko , Gopal Bhatta , Gulab C. Dewangan , Sunil Chandra , Daniela Dorner , Bernd Schleicher , Urszula Pajdosz-Smierciak , Lukasz Stawarz , Staszek Zola , Michal Ostrowski , Daniele Carosati , Saikruba Krishnan , Rumen Bachev , Erika Benitez , Kosmas Gazeas , David Hiriart , Shao-Ming Hu , Valeri Larionov , Alessandro Marchini , Katsura Matsumoto , A. A. Nikiforova , Tapio Pursimo , Claudia M. Raiteri , Daniel E. Reichart , Diego Rodriguez , Evgeni Semkov , Anton Strigachev , Yuki Sugiura , Massimo Villata , James R. Webb , Axel Arbet-Engels , Dominik Baack , Matteo Balbo , Adrian Biland , Thomas Bretz , Jens Buss , Laura Eisenberger , Dominik Elsaesser , Dorothee Hildebrand , Roman Iotov , Adelina Kalenski , Karl Mannheim , Alison Mitchell , Dominik Neise , Maximilian Noethe , Aleksander Paravac , Wolfgang Rhode , Vitalii Sliusar , Roland Walter

Complex Spectral Variability from Intensive Multi-wavelength Monitoring of Mrk421 in 1998

We conducted a multi-frequency campaign for the TeV blazar Mrk~421 in 1998 April. The campaign started from a pronounced high amplitude flare recorded by SAX and Whipple; ASCA observation started three days later. In the X-ray data, we…

Astrophysics · Physics 2009-10-31 T. Takahashi , J. Kataoka , G. Madejski , J. Mattox , C. M. Urry , S. Wagner , F. Aharonian , M. Catanese , L. Chiappetti , P. Coppi , B. Degrange , G. Fossati , H. Kubo , H. Krawczynski , F. Makino , H. Marshall , L. Maraschi , F. Piron , R. Remillard , F. Takahara , M. Tashiro , H. Terasranta , T. Weekes

Hour-Scale Multiwavelength Variability in Markarian 421

Markarian 421 was observed for about four days with BeppoSAX and the Whipple Observatory gamma-ray telescope in April 1998. A pronounced, well-defined, flare with hour-scale variability was observed simultaneously in X-rays and very high…

Astrophysics · Physics 2007-05-23 M. Catanese , I. H. Bond , S. M. Bradbury , A. C. Breslin , J. H. Buckley , A. M. Burdett , D. A. Carter-Lewis , M. F. Cawley , S. Dunlea , M. D'Vali , D. J. Fegan , S. J. Fegan , J. P. Finley , J. A. Gaidos , T. A. Hall , A. M. Hillas , D. Horan , J. Knapp , F. Krennrich , S. Le Bohec , R. W. Lessard , C. Masterson , P. Moriarty , J. Quinn , H. J. Rose , F. W. Samuelson , G. H. Sembroski , V. V. Vassiliev , T. C. Weekes , L. Maraschi , G. Fossati , F. Tavecchio , L. Chiappetti , A. Celotti , G. Ghisellini , P. Grandi , E. Pian , G. Tagliaferri , A. Treves

Long-term monitoring of the TeV emission from Mrk 421 with the ARGO-YBJ experiment

ARGO-YBJ is an air shower detector array with a fully covered layer of resistive plate chambers. It is operated with a high duty cycle and a large field of view. It continuously monitors the northern sky at energies above 0.3 TeV. In this…

High Energy Astrophysical Phenomena · Physics 2015-03-19 YBJ Collaboration , B. Bartoli , P. Bernardini , X. J. Bi , C. Bleve , I. Bolognino , P. Branchini , A. Budano , A. K. Calabrese Melcarne , P. Camarri , Z. Cao , A. Cappa , R. Cardarelli , S. Catalanotti , C. Cattaneo , P. Celio , S. Z. Chen , T. L. Chen , Y. Chen , P. Creti , S. W. Cui , B. Z. Dai , G. D'Alí Staiti , Danzengluobu , M. Dattoli , I. De Mitri , B. D'Ettorre Piazzoli , T. Di Girolamo , X. H. Ding , G. Di Sciascio , C. F. Feng , Zhaoyang Feng , Zhenyong Feng , F. Galeazzi , P. Galeotti , E. Giroletti , Q. B. Gou , Y. Q. Guo , H. H. He , Haibing Hu , Hongbo Hu , Q. Huang , M. Iacovacci , R. Iuppa , I. James , H. Y. Jia , Labaciren , H. J. Li , J. Y. Li , X. X. Li , G. Liguori , C. Liu , C. Q. Liu , J. Liu , M. Y. Liu , H. Lu , X. H. Ma , G. Mancarella , S. M. Mari , G. Marsella , D. Martello , S. Mastroianni , P. Montini , C. C. Ning , A. Pagliaro , M. Panareo , B. Panico , L. Perrone , P. Pistilli , X. B. Qu , E. Rossi , F. Ruggieri , P. Salvini , R. Santonico , P. R. Shen , X. D. Sheng , F. Shi , C. Stanescu , A. Surdo , Y. H. Tan , P. Vallania , S. Vernetto , C. Vigorito , B. Wang , H. Wang , C. Y. Wu , H. R. Wu , B. Xu , L. Xue , Y. X. Yan , Q. Y. Yang , X. C. Yang , Z. G. Yao , A. F. Yuan , M. Zha , H. M. Zhang , Jilong Zhang , Jianli Zhang , L. Zhang , P. Zhang , X. Y. Zhang , Y. Zhang , Zhaxiciren , Zhaxisangzhu , X. X. Zhou , F. R. Zhu , Q. Q. Zhu , G. Zizzi

On the TeV gamma-ray and X-ray correlations exhibited in high-energy peaked BL Lacs: Mrk 501 and 1ES 1959+650

The spectral energy distribution (SED) of blazars is generally understood through the standard one-zone synchrotron self-Compton (SSC) model, where a strong correlation between X-ray and TeV gamma-ray fluxes is expected. Recently, for Mrk…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Mabel Osorio , Rodrigo Sacahui , M. Magdalena González , Nissim Fraija , José Andrés García-González

Multiwavelength Observations of Strong Flares From the TeV-Blazar 1ES 1959+650

Following the detection of strong TeV gamma-ray flares from the BL Lac object 1ES 1959+650 with the Whipple 10 m Cherenkov telescope on May 16 and 17, 2002, we performed intensive Target of Opportunity (ToO) radio, optical, X-ray and TeV…

Astrophysics · Physics 2008-11-26 H. Krawczynski , S. B. Hughes , D. Horan , F. Aharonian , M. F. Aller , H. Aller , P. Boltwood , J. Buckley , P. Coppi , G. Fossati , N. Goetting , J. Holder , D. Horns , O. M. Kurtanidze , A. P. Marscher , M. Nikolashvili , R. A. Remillard , A. Sadun , M. Schroeder

First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign

We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 1 April and 10 August 2013, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign,…

High Energy Astrophysical Phenomena · Physics 2015-10-14 A. Furniss , K. Noda , S. Boggs , J. Chiang , F. Christensen , W. Craig , P . Giommi , C. Hailey , F. Harisson , G. Madejski , K. Nalewajko , M. Perri , D. Stern , M. Urry , F. Verrecchia , W. Zhang , M. L. Ahnen , S. Ansoldi , L. A. Antonelli , P. Antoranz , A. Babic , B. Banerjee , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra Gonzalez , W. Bednarek , E. Bernardini , B. Biasuzzi , A. Biland , O. Blanch , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , E. Carmona , A. Carosi , A. Chatterjee , R. Clavero , 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 , E. de Ona Wilhelmi , C. Delgado Mendez , F. Di Pierro , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher Glawion , D. Elsaesser , A. Fernandez-Barral , D. Fidalgo , M. V. Fonseca , L. Font , K. Frantzen , C. Fruck , D. Galindo , R. J. Garcia Lopez , M. Garczarczyk , D. Garrido Terrats , M. Gaug , P. Giammaria , N. Godinovic , A. Gonzalez Munoz , D. Guberman , Y. Hanabata , M. Hayashida , J. Herrera , J. Hose , D. Hrupec , G. Hughes , W. Idec , H. Kellermann , K. Kodani , Y. Konno , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , N. Lewandowska , E. Lindfors , S. Lombardi , F. Longo , M. Lopez , R. Lopez-Coto , A. Lopez-Oramas , E. Lorenz , P. Majumdar , M. Makariev , K. Mallot , G. Maneva , M. Manganaro , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martinez , D. Mazin , U. Menzel , J. M. Miranda , R. Mirzoyan , A. Moralejo , D. Nakajima , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , K. Nilsson , K. Nishijima , R. Orito , A. Overkemping , S. Paiano , J. Palacio , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , M. Persic , J. Poutanen , P. G. Prada Moroni , E. Prandini , I. Puljak , R. Reinthal , W. Rhode , M. Ribo , J. Rico , J. Rodriguez Garcia , T. Saito , K. Saito , K. Satalecka , V. Scapin , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpaa , J. Sitarek , I. Snidaric , D. Sobczynska , A. Stamerra , T. Steinbring , M. Strzys , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzic , D. Tescaro , M. Teshima , J. Thaele , D. F. Torres , T. Toyama , A. Treves , V. Verguilov , I. Vovk , M. Will , R. Zanin , A. Archer , W. Benbow , R. Bird , J. Biteau , V. Bugaev , J. V Cardenzana , M. Cerruti , X. Chen , L. Ciupik , M. P. Connolly , W. Cui , H. J. Dickinson , J. Dumm , J. D. Eisch , A. Falcone , Q. Feng , J. P. Finley , H. Fleischhack , P. Fortin , L. Fortson , L. Gerard , G. H. Gillanders , S. Griffin , S. T. Griffiths , J. Grube , G. Gyuk , N. Haakansson , J. Holder , T. B. Humensky , C. A. Johnson , P. Kaaret , M. Kertzman , D. Kieda , M. Krause , F. Krennrich , M. J. Lang , T. T. Y. Lin , G. Maier , S. McArthur , A. McCann , K. Meagher , P. Moriarty , R. Mukherjee , D. Nieto , A. O'Faolain de Bhroithe , R. A. Ong , N. Park , D. Petry , M. Pohl , A. Popkow , K. Ragan , G. Ratliff , L. C. Reyes , P. T. Reynolds , G. T. Richards , E. Roache , M. Santander , G. H. Sembroski , K. Shahinyan , D. Staszak , I. Telezhinsky , J. V. Tucci , J. Tyler , V. V. Vassiliev , S. P. Wakely , O. M. Weiner , A. Weinstein , A. Wilhelm , D. A. Williams , B. Zitzer , O. Vince L. Fuhrmann , E. Angelakis , V. Karamanavis , I. Myserlis , T. P. Krichbaum , J. A. Zensus , H. Ungerechts , A. Sievers , R. Bachev , M. Bottcher , W. P. Chen , G. Damljanovic , C. Eswaraiah , T. Guver , T. Hovatta , Z. Hughes , S. . I. Ibryamov , M. D. Joner , B. Jordan , S. G. Jorstad , M. Joshi , J. Kataoka , O. M. Kurtanidze , S. O. Kurtanidze , A. Lahteenmaki , G. Latev , H. C. Lin , V. M. Larionov , A. A. Mokrushina , D. A. Morozova , M. G. Nikolashvili , C. M. Raiteri , V. Ramakrishnan , A. C. R. Readhead , A. C. Sadun , L. A. Sigua , E. H. Semkov , A. Strigachev , J. Tammi , M. Tornikoski , Y. V. Troitskaya I. S. Troitsky , M. Villata

Multiwavelength Observations of the VHE Blazar 1ES 2344+514

Multiwavelength observations of the high-frequency-peaked blazar 1ES2344+514 were performed from 2007 October to 2008 January. The campaign represents the first contemporaneous data on the object at very high energy (VHE, E >100 GeV)…

High Energy Astrophysical Phenomena · Physics 2015-05-28 V. A. Acciari , E. Aliu , T. Arlen , T. Aune , M. Beilicke , W. Benbow , D. Boltuch , V. Bugaev , A. Cannon , L. Ciupik , P. Cogan , P. Colin , R. Dickherber , A. Falcone , S. J. Fegan , J. P. Finley , P. Fortin , L. F. Fortson , A. Furniss , D. Gall , G. H. Gillanders , J. Grube , R. Guenette , G. Gyuk , D. Hanna , J. Holder , D. Horan , C. M. Hui , T. B. Humensky , A. Imran , P. Kaaret , N. Karlsson , M. Kertzman , D. Kieda , J. Kildea , A. Konopelko , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , G. Maier , P. Moriarty , R. Mukherjee , R. A. Ong , A. N. Otte , D. Pandel , J. S. Perkins , A. Pichel , M. Pohl , J. Quinn , K. Ragan , P. T. Reynolds , H. J. Rose , M. Schroedter , G. H. Sembroski , A. W. Smith , D. Steele , S. P. Swordy , M. Theiling , J. A. Toner , A. Varlotta , V. V. Vassiliev , S. Vincent , R. Wagner , S. P. Wakely , J. E. Ward , T. C. Weekes , A. Weinstein , T. Weisgarber , D. A. Williams , S. Wissel , M. Wood , B. Zitzer

X-ray Observations of TeV Blazars and Multi-Frequency Analysis

The non-thermal spectra of blazars, observed from radio to GeV/TeV gamma-rays, reveal two pronounced components, both produced by radiation by energetic particles. One peaks in the IR - to soft X-ray band, radiating via the synchrotron…

Astrophysics · Physics 2009-10-31 Tadayuki Takahashi , Greg Madejski , Hidetoshi Kubo

LHAASO observation of Mrk 421 during 2021 March - 2024 March: a comprehensive VHE catalog of multi-timescale outbursts and its time average behavior

The Large High Altitude Air Shower Observatory (LHAASO) monitors sources within its field of view for up to 7 hours daily, achieving a duty cycle exceeding 98% and an annual point-source sensitivity of 1.5% Crab Units (CU) in the very high…

High Energy Astrophysical Phenomena · Physics 2026-02-17 The LHAASO Collaboration , Zhen Cao , F. Aharonian , Y. X. Bai , Y. W. Bao , D. Bastieri , X. J. Bi , Y. J. Bi , W. Bian , J. Blunier , A. V. Bukevich , C. M. Cai , Y. Y. Cai , W. Y. Cao , Zhe Cao , J. Chang , J. F. Chang , E. S. Chen , G. H. Chen , H. K. Chen , L. F. Chen , Liang Chen , Long Chen , M. J. Chen , M. L. Chen , Q. H. Chen , S. Chen , S. H. Chen , S. Z. Chen , T. L. Chen , X. B. Chen , X. J. Chen , X. P. Chen , Y. Chen , N. Cheng , Q. Y. Cheng , Y. D. Cheng , M. Y. Cui , S. W. Cui , X. H. Cui , Y. D. Cui , B. Z. Dai , H. L. Dai , Z. G. Dai , Danzengluobu , Y. X. Diao , A. J. Dong , X. Q. Dong , K. K. Duan , J. H. Fan , Y. Z. Fan , J. Fang , J. H. Fang , K. Fang , C. F. Feng , H. Feng , L. Feng , S. H. Feng , X. T. Feng , Y. Feng , Y. L. Feng , S. Gabici , B. Gao , Q. Gao , W. Gao , W. K. Gao , M. M. Ge , T. T. Ge , L. S. Geng , G. Giacinti , G. H. Gong , Q. B. Gou , M. H. Gu , F. L. Guo , J. Guo , K. J. Guo , X. L. Guo , Y. Q. Guo , Y. Y. Guo , R. P. Han , O. A. Hannuksela , M. Hasan , H. H. He , H. N. He , J. Y. He , X. Y. He , Y. He , S. Hernández-Cadena , B. W. Hou , C. Hou , X. Hou , H. B. Hu , S. C. Hu , C. Huang , D. H. Huang , J. J. Huang , X. L. Huang , X. T. Huang , X. Y. Huang , Y. Huang , Y. Y. Huang , A. Inventar , X. L. Ji , H. Y. Jia , K. Jia , H. B. Jiang , K. Jiang , X. W. Jiang , Z. J. Jiang , M. Jin , S. Kaci , M. M. Kang , I. Karpikov , D. Khangulyan , D. Kuleshov , K. Kurinov , Cheng Li , Cong Li , D. Li , F. Li , H. B. Li , H. C. Li , Jian Li , Jie Li , K. Li , L. Li , R. L. Li , S. D. Li , T. Y. Li , W. L. Li , X. R. Li , Y. Li , Zhe Li , Zhuo Li , E. W. Liang , Y. F. Liang , S. J. Lin , B. Liu , C. Liu , D. Liu , D. B. Liu , H. Liu , J. Liu , J. L. Liu , J. R. Liu , M. Y. Liu , R. Y. Liu , S. M. Liu , W. Liu , X. Liu , Y. Liu , Y. Liu , Y. N. Liu , Y. Q. Lou , Q. Luo , Y. Luo , H. K. Lv , B. Q. Ma , L. L. Ma , X. H. Ma , I. O. Maliy , J. R. Mao , Z. Min , W. Mitthumsiri , Y. Mizuno , G. B. Mou , A. Neronov , K. C. Y. Ng , M. Y. Ni , L. Nie , L. J. Ou , Z. W. Ou , P. Pattarakijwanich , Z. Y. Pei , D. Y. Peng , J. C. Qi , M. Y. Qi , J. J. Qin , D. Qu , A. Raza , C. Y. Ren , D. Ruffolo , A. Sáiz , D. Savchenko , D. Semikoz , L. Shao , O. Shchegolev , Y. Z. Shen , X. D. Sheng , Z. D. Shi , F. W. Shu , H. C. Song , Yu. V. Stenkin , Y. Su , D. X. Sun , H. Sun , J. X. Sun , Q. N. Sun , X. N. Sun , Z. B. Sun , N. H. Tabasam , J. Takata , P. H. T. Tam , H. B. Tan , Q. W. Tang , R. Tang , Z. B. Tang , W. W. Tian , C. N. Tong , L. H. Wan , C. Wang , D. H. Wang , G. W. Wang , H. G. Wang , J. C. Wang , K. Wang , Kai Wang , Kai Wang , L. P. Wang , L. Y. Wang , L. Y. Wang , R. Wang , W. Wang , X. G. Wang , X. J. Wang , X. Y. Wang , Y. Wang , Y. D. Wang , Z. H. Wang , Z. X. Wang , Zheng Wang , D. M. Wei , J. J. Wei , Y. J. Wei , T. Wen , S. S. Weng , C. Y. Wu , H. R. Wu , Q. W. Wu , S. Wu , X. F. Wu , Y. S. Wu , S. Q. Xi , J. Xia , J. J. Xia , G. M. Xiang , D. X. Xiao , G. Xiao , Y. F. Xiao , Y. L. Xin , H. D. Xing , Y. Xing , D. R. Xiong , B. N. Xu , C. Y. Xu , D. L. Xu , R. F. Xu , R. X. Xu , S. S. Xu , W. L. Xu , L. Xue , D. H. Yan , T. Yan , C. W. Yang , C. Y. Yang , F. F. Yang , L. L. Yang , M. J. Yang , R. Z. Yang , W. X. Yang , Z. H. Yang , Z. G. Yao , X. A. Ye , L. Q. Yin , N. Yin , X. H. You , Z. Y. You , Q. Yuan , H. Yue , H. D. Zeng , T. X. Zeng , W. Zeng , X. T. Zeng , M. Zha , B. B. Zhang , B. T. Zhang , C. Zhang , H. Zhang , H. M. Zhang , H. Y. Zhang , J. L. Zhang , J. Y. Zhang , Li Zhang , P. F. Zhang , R. Zhang , S. R. Zhang , S. S. Zhang , S. Y. Zhang , W. Zhang , W. Y. Zhang , X. Zhang , X. P. Zhang , Yi Zhang , Yong Zhang , Z. P. Zhang , J. Zhao , L. Zhao , L. Z. Zhao , S. P. Zhao , X. H. Zhao , Z. H. Zhao , F. Zheng , T. C. Zheng , B. Zhou , H. Zhou , J. N. Zhou , M. Zhou , P. Zhou , R. Zhou , X. X. Zhou , X. X. Zhou , B. Y. Zhu , C. G. Zhu , F. R. Zhu , H. Zhu , K. J. Zhu , Y. C. Zou , X. Zuo

First Results from NuSTAR Observations of Mkn 421

Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad non-thermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in…

High Energy Astrophysical Phenomena · Physics 2015-06-17 M. Baloković , M. Ajello , R. D. Blandford , S. E. Boggs , F. Borracci , J. Chiang , F. E. Christensen , W. W. Craig , K. Forster , A. Furniss , F. Fuerst , G. Ghisellini , B. Giebels , P. Giommi , B. W. Grefenstette , C. J. Hailey , F. A. Harrison , M. Hayashida , B. Humensky , Y. Inoue , J. E. Koglin , H. Krawczynski , G. M. Madejski , K. K. Madsen , D. L. Meier , T. Nelson , P. Ogle , D. Paneque , M. Perri , S. Puccetti , C. S. Reynolds , T. Sbarrato , D. Stern , G. Tagliaferri , C. M. Urry , A. E. Wehrle , W. W. Zhang

M@TE - Monitoring at TeV Energies

Blazars are extremely variable objects emitting radiation across the electromagnetic spectrum and showing variability on time scales from minutes to years. For the understanding of the emission mechanisms, simultaneous multi-wavelength…

Instrumentation and Methods for Astrophysics · Physics 2017-08-09 Daniela Dorner , Thomas Bretz , Magdalena Gonzalez , Ruben Alfaro , Gagik Tovmassian

Observations of Mkn 421 during 1997 and 1998 in the energy range above 500 GeV with the HEGRA stereoscopic Cherenkov telescope system

Since its commissioning in fall 1996, the stereoscopic system of Imaging Atmospheric Cherenkov Telescope (IACTs) of HEGRA with an energy threshold of 500 GeV, an angular resolution of 0.1 degree and an energy resolution of 20% per…

Astrophysics · Physics 2007-05-23 F. A. Aharonian

A combined radio and GeV gamma-ray view of the 2012 and 2013 flares of Mrk 421

In 2012 Markarian 421 underwent the largest flare ever observed in this blazar at radio frequencies. In the present study, we start exploring this unique event and compare it to a less extreme event in 2013. We use 15 GHz radio data…

High Energy Astrophysical Phenomena · Physics 2015-06-23 T. Hovatta , M. Petropoulou , J. L. Richards , D. Giannios , K. Wiik , M. Baloković , A. Lähteenmäki , B. Lott , W. Max-Moerbeck , V. Ramakrishnan , A. C. S. Readhead

A luminous and isolated gamma-ray flare from the blazar B2 1215+30

B2 1215+30 is a BL Lac-type blazar that was first detected at TeV energies by the MAGIC atmospheric Cherenkov telescopes, and subsequently confirmed by the VERITAS observatory with data collected between 2009 and 2012. In 2014 February 08,…

High Energy Astrophysical Phenomena · Physics 2017-02-23 VERITAS Collaboration , A. U. Abeysekara , S. Archambault , A. Archer , W. Benbow , R. Bird , M. Buchovecky , J. H. Buckley , V. Bugaev , K. Byrum , M. Cerruti , X. Chen , L. Ciupik , W. Cui , H. J. Dickinson , J. D. Eisch , M. Errando , A. Falcone , Q. Feng , J. P. Finley , H. Fleischhack , L. Fortson , A. Furniss , G. H. Gillanders , S. Griffin , J. Grube , M. Hutten , N. Hakansson , D. Hanna , J. Holder , T. B. Humensky , C. A. Johnson , P. Kaaret , P. Kar , M. Kertzman , D. Kieda , M. Krause , F. Krennrich , S. Kumar , M. J. Lang , G. Maier , S. McArthur , A. McCann , K. Meagher , P. Moriarty , R. Mukherjee , T. Nguyen , D. Nieto , R. A. Ong , A. N. Otte , N. Park , V. Pelassa , M. Pohl , A. Popkow , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , G. T. Richards , E. Roache , C. Rulten , M. Santander , G. H. Sembroski , K. Shahinyan , D. Staszak , I. Telezhinsky , J. V. Tucci , J. Tyler , S. P. Wakely , O. M. Weiner , A. Weinstein , A. Wilhelm , D. A. Williams , Fermi-LAT Collaboration , : , S. Fegan , B. Giebels , D. Horan , A. Berdyugin , J. Kuan , E. Lindfors , K. Nilsson , A. Oksanen , H. Prokoph , R. Reinthal , L. Takalo , F. Zefi

X-ray Intraday Variability of Five TeV Blazars with NuSTAR

We have examined 40 NuSTAR light curves (LCs) of five TeV emitting high synchrotron peaked blazars: 1ES 0229+200, Mrk 421, Mrk 501, 1ES 1959+650 and PKS 2155-304. Four of the blazars showed intraday variability in the NuSTAR energy range of…

High Energy Astrophysical Phenomena · Physics 2017-12-20 Ashwani Pandey , Alok C. Gupta , Paul J. Wiita

Joint analysis of TeV blazar light curves with FACT and HAWC

Probing the high energy emission processes of blazars through their variability relies crucially on long-term monitoring. We present unprecedented light curves from unbiased observations of very high energy fluxes from the blazars Mrk 421…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Daniela Dorner , Robert J. Lauer