Related papers: SST-1M Observations of Markarian 421

Observations of Mkn 421 with the CELESTE Experiment

The CELESTE experiment uses the heliostats of an old solar farm in the French Pyrenees to detect gamma ray air showers by the atmospheric Cerenkov technique. Observations of the TeV blazar Markarian 421 have been made with the fully…

Astrophysics · Physics 2017-08-23 J. Holder , CELESTE collaboration

Very-high-energy gamma-ray emission from high-redshift blazars

We study the possible detection of and properties of very high-energy (VHE) gamma-ray emission (in the energy band above 100 GeV) from high redshift sources. We report on the detection of VHE gamma-ray flux from blazars with redshifts…

High Energy Astrophysical Phenomena · Physics 2015-08-20 A. Neronov , D. V. Semikoz , A. M. Taylor , Ie. Vovk

Observation of gamma-rays greater than 10 TeV from Markarian 421

We have observed Markarian 421 in January and March 2001 with the CANGAROO-II imaging Cherenkov telescope during an extraordinarily high state at TeV energies. From 14 hours observations at very large zenith angles, $\sim70^\circ$, a signal…

Astrophysics · Physics 2009-11-07 K. Okumura , A. Asahara , G. V. Bicknell , P. G. Edwards , R. Enomoto , S. Gunji , S. Hara , T. Hara , S. Hayashi , C. Itoh , S. Kabuki , F. Kajino , H. Katagiri , J. Kataoka , A. Kawachi , T. Kifune , H. Kubo , J. Kushida , S. Maeda , A. Maeshiro , Y. Matsubara , Y. Mizumoto , M. Mori , M. Moriya , H. Muraishi , Y. Muraki , T. Naito , T. Nakase , K. Nishijima , M. Ohishi , J. R. Patterson , K. Sakurazawa , R. Suzuki , D. L. Swaby , K. Takano , T. Takano , T. Tanimori , F. Tokanai , K. Tsuchiya , H. Tsunoo , K. Uruma , A. Watanabe , S. Yanagita , T. Yoshida , T. Yoshikoshi

Search for gamma-rays above 10 TeV from Markarian 421 in a high state with the CANGAROO-II telescope

A preliminary result from Markarian 421 observations in the energy region above 10 TeV with the CANGAROO-II 10 m telescope is presented. In January 2001, the HEGRA group reported that Markarian 421 had become very active, with flux levels…

Astrophysics · Physics 2007-05-23 K. Okumura , R. Enomoto , A. Asahara , G. V. Bicknell , P. G. Edwards , S. Gunji , S. Hara , T. Hara , S. Hayashi , C. Itoh , S. Kabuki , F. Kajino , H. Katagiri , J. Kataoka , A. Kawachi , T. Kifune , H. Kubo , J. Kushida , S. Maeda , A. Maeshiro , Y. Matsubara , Y. Mizumoto , M. Mori , M. Moriya , H. Muraishi , Y. Muraki , T. Naito , T. Nakase , K. Nishijima , M. Ohishi , J. R. Patterson , K. Sakurazawa , R. Suzuki , D. L. Swaby , K. Takano , T. Takano , T. Tanimori , F. Tokanaia , K. Tsuchiya , H. Tsunoo , K. Uruma , A. Watanabe , S. Yanagita , T. Yoshida , T. Yoshikoshi

The TeV Energy Spectrum of Mrk 421 Measured in A High Flaring State

The BL Lac object (blazar) Mrk 421 was observed during its outburst in April 2004 with the Whipple 10 m telescope for a total of about 24.5 hours. The measured gamma-ray rate varied substantially over the range from 4 to 10 gamma's/min and…

Astrophysics · Physics 2009-11-13 A. Konopelko , W. Cui , C. Duke , J. P. Finley

Study of the long-term Very High Energy emission of the blazars 1ES 1215+3031 and VER J0521+211 with the HAWC gamma-ray observatory

Blazars are the most abundant type of extragalactic gamma-ray source, usually presenting high variability across the electromagnetic spectrum. Their Very High Energy (VHE, above 0.1 TeV) emission has been studied in detail using Air…

High Energy Astrophysical Phenomena · Physics 2023-10-05 Fernando Ureña-Mena , Alberto Carramiñana , Anna Lia Longinotti , Daniel Rosa-González , HAWC Collaboration

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

The Great Markarian 421 Flare of February 2010: Multiwavelength variability and correlation studies

We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of February, 2010 when an extraordinary flare reaching a level of $\sim$27~Crab Units above 1~TeV was measured in…

High Energy Astrophysical Phenomena · Physics 2020-04-06 A. U. Abeysekara , W. Benbow , R. Bird , A. Brill , R. Brose , M. Buchovecky , J. H. Buckley , J. L. Christiansen , A. J. Chromey , M. K. Daniel , J. Dumm , A. Falcone , Q. Feng , J. P. Finley , L. Fortson , A. Furniss , N. Galante , A. Gent , G. H. Gillanders , C. Giuri , O. Gueta , T. Hassan , O. Hervet , J. Holder , G. Hughes , T. B. Humensky , C. A. Johnson , P. Kaaret , P. Kar , N. Kelley-Hoskins , M. Kertzman , D. Kieda , M. Krause , F. Krennrich , S. Kumar , M. J. Lang , P. Moriarty , R. Mukherjee , T. Nelson , D. Nieto , M. Nievas-Rosillo , S. O'Brien , R. A. Ong , A. N. Otte , N. Park , A. Petrashyk , A. Pichel , M. Pohl , R. R. Prado , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , G. T. Richards , E. Roache , A. C. Rovero , C. Rulten , I. Sadeh , M. Santander , G. H. Sembroski , K. Shahinyan , B. Stevenson , I. Sushch , J. Tyler , V. V. Vassiliev , S. P. Wakely , A. Weinstein , R. M. Wells , P. Wilcox , A. Wilhelm , D. A. Williams , B. Zitzer , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , D. Baack , A. Babić , B. Banerjee , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , L. Bellizzi , E. Bernardini , A. Berti , J. Besenrieder , W. Bhattacharyya , C. Bigongiari , A. Biland , O. Blanch , G. Bonnoli , G. Busetto , R. Carosi , G. Ceribella , Y. Chai , S. Cikota , S. M. Colak , U. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , V. D'Elia , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , M. Delfino , J. Delgado , F. Di Pierro , E. Do Souto Espiñera , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , A. Fernández-Barral , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , D. Galindo , S. Gallozzi , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , N. Godinović , D. Green , D. Guberman , D. Hadasch , A. Hahn , J. Herrera , J. Hoang , D. Hrupec , S. Inoue , K. Ishio , Y. Iwamura , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , M. López , R. López-Coto , A. López-Oramas , B. Machado de Oliveira Fraga , C. Maggio , P. Majumdar , M. Makariev , M. Mallamaci , G. Maneva , M. Manganaro , K. Mannheim , L. Maraschi , M. Mariotti , M. Martínez , S. Masuda , D. Mazin , D. Miceli , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , D. Morcuende , V. Moreno , E. Moretti , P. Munar-Adrover , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , M. Nöthe , S. Paiano , J. Palacio , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , P. Peñil , M. Peresano , M. Persic , P. G. Prada Moroni , E. Prandini , I. Puljak , W. Rhode , M. Ribó , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , K. Satalecka , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , D. Strom , M. Strzys , S. Sun , T. Surić , F. Tavecchio , P. Temnikov , T. Terzić , M. Teshima , N. Torres-Albà , S. Tsujimoto , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , I. Vovk , M. Will , D. Zarić , H. D. Aller , M. F. Aller , M. T. Carini , D. Horan , B. Jordan , Svetlana G. Jorstad , O. M. Kurtanidze , S. O. Kurtanidze , A. Lähteenmäki , V. M. Larionov , E. G. Larionova , G. Madejski , Alan P. Marscher , W. Max-Moerbeck , J. Ward Moody , D. A. Morozova , M. G. Nikolashvili , C. M. Raiteri , A. C. S. Readhead , J. L. Richards , Alberto C. Sadun , T. Sakamoto , L. A. Sigua , P. S. Smith , H. Talvikki , J. Tammi , M. Tornikoski , I. S. Troitsky , M. Villata

Long-term multi-wavelength variability and correlation study of Markarian 421 from 2007 to 2009

We study the multi-band variability and correlations of the TeV blazar Mrk 421 on year time scales, which can bring additional insight on the processes responsible for its broadband emission. We observed Mrk 421 in the very high energy…

Astrophysics of Galaxies · Physics 2019-08-15 MAGIC Collaboration , 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 González , W. Bednarek , E. Bernardini , B. Biasuzzi , A. Biland , O. Blanch , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , S. Buson , 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 , B. De Lotto , E. de Oña Wilhelmi , F. Di Pierro , A. Domínguez , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher Glawion , D. Elsaesser , A. Fernández-Barral , D. Fidalgo , M. V. Fonseca , L. Font , K. Frantzen , C. Fruck , D. Galindo , R. J. García López , M. Garczarczyk , D. Garrido Terrats , M. Gaug , P. Giammaria , N. Godinović , A. González Muñoz , D. Gora , D. Guberman , D. Hadasch , A. Hahn , Y. Hanabata , M. Hayashida , J. Herrera , J. Hose , D. Hrupec , G. Hughes , W. Idec , K. Kodani , Y. Konno , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , E. Lindfors , S. Lombardi , F. Longo , M. López , R. López-Coto , P. Majumdar , M. Makariev , K. Mallot , G. Maneva , M. Manganaro , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martínez , D. Mazin , U. Menzel , J. M. Miranda , R. Mirzoyan , A. Moralejo , E. Moretti , D. Nakajima , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , K. Nilsson , K. Nishijima , K. Noda , L. Nogués , R. Orito , A. Overkemping , S. Paiano , J. Palacio , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , G. Pedaletti , L. Perri , M. Persic , J. Poutanen , P. G. Prada Moroni , E. Prandini , I. Puljak , W. Rhode , M. Ribó , J. Rico , J. Rodriguez Garcia , T. Saito , K. Satalecka , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , A. Stamerra , T. Steinbring , M. Strzys , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , J. Thaele , D. F. Torres , T. Toyama , A. Treves , V. Verguilov , I. Vovk , J. E. Ward , M. Will , M. H. Wu , R. Zanin , D. A. Blinov , W. P. Chen , N. V. Efimova , E. Forné , T. S. Grishina , T. Hovatta , B. Jordan , G. N. Kimeridze , E. N. Kopatskaya , E. Koptelova , O. M. Kurtanidze , S. O. Kurtanidze , A. Lähteenmaäki , V. M. Larionov , E. G. Larionova , L. V. Larionova , R. Ligustri , H. C. Lin , B. McBreen , D. A. Morozova , M. G. Nikolashvili , C. M. Raiteri , J. A. Ros , A. C. Sadun , L. A. Sigua , M. Tornikoski , I. S. Troitsky , M. Villata

Time dependent spectral modeling of Markarian 421 during a violent outburst in 2010

We present the results of extensive modeling of the spectral energy distributions (SEDs) of the closest blazar (z=0.031) Markarian 421 (Mrk 421) during a giant outburst in February 2010. The source underwent rapid flux variations in both…

Astrophysics of Galaxies · Physics 2019-05-29 B. Banerjee , M. Joshi , P. Majumdar , K. E. Williamson , S. G. Jorstad , A. P. Marscher

VERITAS observation of Markarian 421 flaring activity

Markarian 421 is one of the brightest BL-Lac objects in gamma-rays in the northern hemisphere. Because of its brightness, the source has been the focus of several coordinated multi-wavelength (MWL) campaigns designed to study the physical…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Nicola Galante

H.E.S.S. discovery of very-high-energy gamma-ray emission of PKS 1440-389

Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, since less than 60…

High Energy Astrophysical Phenomena · Physics 2019-08-14 H. Prokoph , Y. Becherini , M. Böttcher , C. Boisson , J. -P. Lenain , I. Sushch

VLBA monitoring of Mrk 421 at 15 and 24 GHz during 2011

We present a preliminary analysis of new high resolution radio observations of the nearby TeV blazar Markarian 421 (z=0.031). This study is part of an ambitious multifrequency campaign, with observations in sub-mm (SMA), optical/IR (GASP),…

High Energy Astrophysical Phenomena · Physics 2012-05-03 R. Lico , M. Giroletti , M. Orienti , G. Giovannini , B. Cotton , P. Edwards , L. Fuhrmann , T. Krichbaum , K. Sokolovsky , S. Jorstad , A. Marscher , M. Kino , Y. Kovalev , D. Paneque , M. A. Perez-Torres , G. Piner

An active state of the BL Lac Object Markarian 421 detected by INTEGRAL in April 2013

Multiwavelength variability of blazars offers indirect insight into their powerful engines and on the mechanisms through which energy is propagated from the centre down the jet. The BL Lac object Mkn 421 is a TeV emitter, a bright blazar at…

High Energy Astrophysical Phenomena · Physics 2014-10-22 E. Pian , M. Tuerler , M. Fiocchi , R. Boissay , A. Bazzano , L. Foschini , F. Tavecchio , V. Bianchin , G. Castignani , C. Ferrigno , C. M. Raiteri , M. Villata , V. Beckmann , F. D'Ammando , R. Hudec , G. Malaguti , L. Maraschi , T. Pursimo , P. Romano , S. Soldi , A. Stamerra , A. Treves , P. Ubertini , S. Vercellone , R. Walter

H.E.S.S. discovery of very-high-energy emission from the blazar PKS 0736+017: on the location of the $\gamma$-ray emitting region in FSRQs

With the installation of a new 28-m diameter imaging atmospheric Cherenkov telescope in the middle of the array, the H.E.S.S. instrument has entered since 2012 into its Phase II. The fifth large-size telescope is particularly important to…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Matteo Cerruti , Jean-Philippe Lenain , Heike Prokoph

Variable VHE gamma-ray emission from Markarian 501

The blazar Markarian 501 (Mrk 501) was observed at energies above 0.10 TeV with the MAGIC telescope from May through July 2005. The high sensitivity of the instrument enabled the determination of the flux and spectrum of the source on a…

Astrophysics · Physics 2010-11-11 J. Albert et al

FACT -- Multi-wavelength analysis of more than 30 flares of Mrk 421

Mrk 421 is a high-synchrotron-peaked blazar featuring bright and persistent GeV and TeV emission. We use multi-wavelength light curves of Mrk 421 spanning 5.5 years with FACT (TeV) and Fermi LAT (GeV) in the gamma rays, Swift BAT, Swift XRT…

High Energy Astrophysical Phenomena · Physics 2019-08-27 Vitalii Sliusar , Axel Arbet-Engels , Dominik Baack , Matteo Balbo , Adrian Biland , Michael Blank , Tomas Bretz , Kai Bruegge , Michael Bulinski , Jens Buss , Manuel Doerr , Daniela Dorner , Dominik Elsaesser , Dorothee Hildebrand , Karl Mannheim , Sebastian mueller , Dominik Neise , Maximilian Noethe , Aleksander Paravac , Wolfgang Rhode , Bernd Schleicher , Kevin Sedlaczek , Amit Shukla , Roland Walter , Elan von Willert

MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength context

We present a study of the very high energy (VHE; E > 100 GeV) gamma-ray emission of the blazar PKS 1424+240 observed with the MAGIC telescopes. The primary aim of this paper is the multiwavelength spectral characterization and modeling of…

High Energy Astrophysical Phenomena · Physics 2014-09-05 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 , 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 , S. Cutini , D. Gasparrini , A. Furniss , T. Hovatta , T. Kangas , E. Kankare , J. Kotilainen , M. Lister , A. Lähteenmäki , W. Max-Moerbeck , V. Pavlidou , A. Readhead , J. Richards

Simultaneous X-Ray and TeV Gamma-Ray Observations of the TeV Blazar Markarian 421 during February and May 2000

In this paper we present the results of simultaneous observations of the TeV blazar Markarian 421 (Mrk 421) at X-ray and TeV Gamma-ray energies with the Rossi X-Ray Timing Explorer (RXTE) and the stereoscopic Cherenkov Telescope system of…

Astrophysics · Physics 2009-11-06 H. Krawczynski , R. Sambruna , A. Kohnle , P. S. Coppi , The HEGRA Collaboration , F. Aharonian

Multi-wavelength observations of the TeV Blazars Mkn~421, 1ES1959+650, and H1426+428 with the HEGRA Cherenkov telescopes and the RXTE X-ray satellite

Recent results obtained with the HEGRA system of imaging Cherenkov telescopes on the TeV emission of the Blazars Mkn~421 ($z=0.030$), 1ES1959+650 ($z=0.047$), and H1426+428 ($z=0.129$) are reported. For Mkn~421, a close connection of the…

Astrophysics · Physics 2007-05-23 D. Horns , the HEGRA collaboration