Related papers: Whipple Observations of BL Lac Objects

Discovery of Very High Energy gamma - ray emission from the extreme BL Lac object H2356-309 with H.E.S.S

The understanding of acceleration mechanisms in active galactic nuclei (AGN) jets and the measurement of the extragalactic-background-light (EBL) density are closely linked and require the detection of a large sample of very-high-energy…

Astrophysics · Physics 2016-08-15 S. Pita , W. Benbow , L. Costamante , A. Djannati-Ataï , D. Horns , M. Ouchrif , M. Tluczykont , the HESS Collaboration

Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes

We study the non-thermal jet emission of the BL Lac object B3 2247+381 during a high optical state. The MAGIC telescopes observed the source during 13 nights between September 30th and October 30th 2010, collecting a total of 14.2 hours of…

High Energy Astrophysical Phenomena · Physics 2016-08-14 The MAGIC Collaboration , J. Aleksić , E. A. Alvarez , L. A. Antonelli , P. Antoranz , M. Asensio , M. Backes , J. A. Barrio , D. Bastieri , J. Becerra González , W. Bednarek , A. Berdyugin , K. Berger , E. Bernardini , A. Biland , O. Blanch , R. K. Bock , A. Boller , G. Bonnoli , D. Borla Tridon , I. Braun , T. Bretz , A. Cañellas , E. Carmona , A. Carosi , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , L. Cossio , S. Covino , F. Dazzi , A. De Angelis , G. De Caneva , E. De Cea del Pozo , B. De Lotto , C. Delgado Mendez , A. Diago Ortega , M. Doert , A. Domínguez , D. Dominis Prester , D. Dorner , M. Doro , D. Elsaesser , D. Ferenc , M. V. Fonseca , L. Font , C. Fruck , R. J. García López , M. Garczarczyk , D. Garrido , G. Giavitto , N. Godinović , D. Hadasch , D. Häfner , A. Herrero , D. Hildebrand , D. Höhne-Mönch , J. Hose , D. Hrupec , B. Huber , T. Jogler , H. Kellermann , S. Klepser , T. Krähenbühl , J. Krause , A. La Barbera , D. Lelas , E. Leonardo , E. Lindfors , S. Lombardi , M. López , A. López-Oramas , E. Lorenz , M. Makariev , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , M. Mariotti , M. Martínez , D. Mazin , M. Meucci , J. M. Miranda , R. Mirzoyan , H. Miyamoto , J. Moldón , A. Moralejo , P. Munar-Adrover , D. Nieto , K. Nilsson , R. Orito , I. Oya , D. Paneque , R. Paoletti , S. Pardo , J. M. Paredes , S. Partini , M. Pasanen , F. Pauss , M. A. Perez-Torres , M. Persic , L. Peruzzo , M. Pilia , J. Pochon , F. Prada , P. G. Prada Moroni , E. Prandini , I. Puljak , I. Reichardt , R. Reinthal , W. Rhode , M. Ribó , J. Rico , S. Rügamer , A. Saggion , K. Saito , T. Y. Saito , M. Salvati , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , M. Shayduk , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , S. Spiro , V. Stamatescu , A. Stamerra , B. Steinke , J. Storz , N. Strah , T. Surić , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , O. Tibolla , D. F. Torres , A. Treves , M. Uellenbeck , H. Vankov , P. Vogler , R. M. Wagner , Q. Weitzel , V. Zabalza , F. Zandanel , R. Zanin , V. Kadenius , M. Weidinger , S. Buson

New hard-TeV extreme blazars detected with the MAGIC telescopes

Extreme high-frequency peaked BL Lac objects (EHBLs) are blazars which exhibit extremely energetic synchrotron emission. They also feature non-thermal gamma-ray emission whose peak lies in the very high-energy (VHE, E > 100 GeV) range, and…

High Energy Astrophysical Phenomena · Physics 2020-08-21 MAGIC Collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , K. Asano , 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 , Ž. Bošnjak , G. Busetto , R. Carosi , G. Ceribella , M. Cerruti , Y. Chai , A. Chilingaryan , 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 , D. Depaoli , F. Di Pierro , L. Di Venere , E. Do Souto Espiñeira , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , S. Fukami , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , N. Giglietto , F. Giordano , N. Godinović , D. Green , D. Guberman , D. Hadasch , A. Hahn , J. Herrera , J. Hoang , D. Hrupec , M. Hütten , T. Inada , S. Inoue , K. Ishio , Y. Iwamura , L. Jouvin , D. Kerszberg , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , M. López , R. López-Coto , A. López-Oramas , S. Loporchio , 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 , D. Mazin , S. Mićanović , D. Miceli , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , D. Morcuende , V. Moreno , E. Moretti , P. Munar-Adrover , V. Neustroev , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , S. Nozaki , S. Paiano , 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 , S. Sakurai , K. Satalecka , K. Schmidt , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , D. Strom , M. Strzys , Y. Suda , T. Surić , M. Takahashi , F. Tavecchio , P. Temnikov , T. Terzić , M. Teshima , N. Torres-Albà , L. Tosti , V. Vagelli , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , C. F. Vigorito , V. Vitale , I. Vovk , M. Will , D. Zarić , C. Arcaro , A. Carosi , F. D'Ammando , F. Tombesi , A. Lohfink

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

Observations of the high-frequency-peaked BL Lac object 1ES 1218+304 with VERITAS

The VERITAS collaboration has observed the high-frequency-peaked BL Lac object 1ES 1218+304 using an array of several imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in Southern Arizona. A gamma-ray signal was…

Astrophysics · Physics 2007-09-25 Pascal Fortin

Discovery of hard-spectrum \gamma-ray emission from the BL Lac object 1ES 0414+009

1ES 0414+009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE, E>100 GeV) gamma-rays due to its high X-ray and radio flux. Observations in the VHE gamma-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-03 The HESS Collaboration , A. Abramowski , F. Acero , F. Aharonian , A. G. Akhperjanian , G. Anton , A. Balzer , A. Barnacka , U. Barres de Almeida , Y. Becherini , J. Becker , B. Behera , K. Bernlöhr , E. Birsin , J. Biteau , A. Bochow , C. Boisson , J. Bolmont , P. Bordas , J. Brucker , F. Brun , P. Brun , T. Bulik , I. Büsching , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , A. Charbonnier , R. C. G. Chaves , A. Cheesebrough , L. -M. Chounet , A. C. Clapson , G. Coignet , G. Cologna , J. Conrad , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange , C. Deil , H. J. Dickinson , A. Djannati-Ataï , W. Domainko , L. O'C. Drury , F. Dubois , G. Dubus , K. Dutson , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat , L. Fallon , C. Farnier , F. Feinstein , M. V. Fernandes , A. Fiasson , G. Fontaine , A. Förster , M. Füßling , Y. A. Gallant , H. Gast , L. Gérard , D. Gerbig , B. Giebels , J. F. Glicenstein , B. Glück , P. Goret , D. Göring , S. Häffner , J. D. Hague , D. Hampf , M. Hauser , S. Heinz , G. Heinzelmann , G. Henri , G. Hermann , J. A. Hinton , A. Hoffmann , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska , O. C. de Jager , C. Jahn , M. Jamrozy , I. Jung , M. A. Kastendieck , K. Katarzynski , U. Katz , S. Kaufmann , D. Keogh , D. Khangulyan , B. Khélifi , D. Klochkov W. Kluźniak , T. Kneiske , Nu. Komin , K. Kosack , R. Kossakowski , H. Laffon , G. Lamanna , D. Lennarz , T. Lohse , A. Lopatin , C. -C. Lu , V. Marandon , A. Marcowith , J. Masbou , D. Maurin , N. Maxted , M. Mayer , T. J. L. McComb , M. C. Medina , J. Méhault , R. Moderski , E. Moulin , C. L. Naumann , M. Naumann-Godo , M. de Naurois , D. Nedbal , D. Nekrassov , N. Nguyen , B. Nicholas , J. Niemiec , S. J. Nolan , S. Ohm , E. de Ona Wilhelmi , B. Opitz , M. Ostrowski , I. Oya , M. Panter , M. Paz Arribas , G. Pedaletti , G. Pelletier , P. -O. Petrucci , S. Pita , G. Pühlhofer , M. Punch , A. Quirrenbach , M. Raue , S. M. Rayner , A. Reimer , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , J. Ripken , L. Rob , S. Rosier-Lees , G. Rowell , B. Rudak , C. B. Rulten , J. Ruppel , V. Sahakian , D. A. Sanchez , A. Santangelo , R. Schlickeiser , F. M. Schöck , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , F. Sheidaei , M. Sikora , J. L. Skilton , H. Sol , G. Spengler , L. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek , J. -P. Tavernet , R. Terrier , M. Tluczykont , K. Valerius , C. van Eldik , G. Vasileiadis , C. Venter , J. P. Vialle , A. Viana , P. Vincent , H. J. Völk , F. Volpe , S. Vorobiov , M. Vorster , S. J. Wagner , M. Ward , R. White , A. Wierzcholska , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin , L. Costamante , S. Fegan , M. Ajello

Studying flux variability of the BL Lac object 1ES0806+524 with MAGIC in a multi-wavelength context

We present results of multi-wavelength (MWL) observations of the high-frequency-peaked BL Lacertae (HBL) object 1ES 0806+524 (z=0.138). Triggered by a high optical state, very high energy (VHE; E > 100 GeV) observations were carried out…

High Energy Astrophysical Phenomena · Physics 2019-08-15 K. Berger , C. Schultz , E. Lindfors R. Rheinthal , A. Stamerra , F. Tavecchio , S. Buson , F. D'Ammando , T. Hovatta

Exploring the Most Extreme Blazars: New Insights from MAGIC

Extremely high-peaked BL Lac objects (or extreme blazars) are unique extragalactic laboratories where particle acceleration processes are pushed at their physical limits. In these blazars, synchrotron emission peaking above keV energies is…

High Energy Astrophysical Phenomena · Physics 2025-10-08 L. Foffano , C. Arcaro , A. Arbet-Engels , F. D'Ammando , P. Da Vela , J. Jormanainen , D. Linder , S. Menon , E. Prandini , S. Ventura , E. Visentin

Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC Telescopes and simultaneous multi-wavelength observations

Context. We present the discovery of very high energy (VHE, E > 100GeV) gamma-ray emission from the BL Lac object 1ES 1215+303 by the MAGIC telescopes and simultaneous multi-wavelength data in a broad energy range from radio to gamma-rays.…

High Energy Astrophysical Phenomena · Physics 2012-08-21 MAGIC Collaboration , J. Aleksić , E. A. Alvarez , L. A. Antonelli , P. Antoranz , S. Ansoldi , M. Asensio , M. Backes , U. Barres de Almeida , J. A. Barrio , D. Bastieri , J. Becerra González , W. Bednarek , K. Berger , E. Bernardini , A. Biland , O. Blanch , R. K. Bock , A. Boller , G. Bonnoli , D. Borla Tridon , T. Bretz , A. Cañellas , E. Carmona , A. Carosi , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , L. Cossio , S. Covino , P. Da Vela , F. Dazzi , A. De Angelis , G. De Caneva , E. De Cea del Pozo , B. De Lotto , C. Delgado Mendez , A. Diago Ortega , M. Doert , A. Domínguez , D. Dominis Prester , D. Dorner , M. Doro , D. Eisenacher , D. Elsaesser , D. Ferenc , M. V. Fonseca , L. Font , C. Fruck , R. J. García López , M. Garczarczyk , D. Garrido Terrats , G. Giavitto , N. Godinović , A. González Muñoz , S. R. Gozzini , D. Hadasch , D. Häfner , A. Herrero , D. Hildebrand , J. Hose , D. Hrupec , B. Huber , F. Jankowski , T. Jogler , V. Kadenius , H. Kellermann , S. Klepser , T. Krähenbühl , J. Krause , A. La Barbera , D. Lelas , E. Leonardo , N. Lewandowska , E. Lindfors , S. Lombardi , M. López , R. López-Coto , A. López-Oramas , E. Lorenz , M. Makariev , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , M. Mariotti , M. Martínez , D. Mazin , M. Meucci , J. M. Miranda , R. Mirzoyan , J. Moldón , A. Moralejo , P. Munar-Adrover , A. Niedzwiecki , D. Nieto , K. Nilsson , N. Nowak , R. Orito , S. Paiano , D. Paneque , R. Paoletti , S. Pardo , J. M. Paredes , S. Partini , M. A. Perez-Torres , M. Persic , M. Pilia , J. Pochon , F. Prada , P. G. Prada Moroni , E. Prandini , I. Puerto Gimenez , I. Puljak , I. Reichardt , R. Reinthal , W. Rhode , M. Ribó , J. Rico , S. Rügamer , A. Saggion , K. Saito , T. Y. Saito , M. Salvati , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , S. Spiro , V. Stamatescu , A. Stamerra , B. Steinke , J. Storz , N. Strah , S. Sun , T. Surić , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , O. Tibolla , D. F. Torres , A. Treves , M. Uellenbeck , P. Vogler , R. M. Wagner , Q. Weitzel , V. Zabalza , F. Zandanel , R. Zanin , A. Berdyugin , S. Buson , E. Järvelä , S. Larsson , A. Lähteenmäki , J. Tammi

Observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304 with the MAGIC telescopes

The two BL Lac objects 1ES 1215+303 and 1ES 1218+304, separated by 0.8 deg, were observed with the MAGIC telescopes in 2010 and 2011. The 20 hours of data registered in January 2011 resulted in the first detection at Very High Energy (>100…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Pierre Colin , Josefa Becerra Gonzalez , Elina Lindfors , Saverio Lombardi , Julian Sitarek , Antonio Stamera

Recent H.E.S.S. results on extra-galactic sources

Since the beginning of scientific operations in 2003, more than 20 extra-galactic sources have been detected with H.E.S.S. (High Energy Stereoscopic System) at very high energies (VHE): apart from the starburst galaxy NGC 253, all of them…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Matteo Cerruti

Discovery of very high-energy gamma-ray emission from the LBL object BL Lacertae

The low-frequency peaked BL Lac (LBL) object BL Lacertae was observed with the MAGIC telescope from 2005 August to December (22.2 hr), and from 2006 July to September (26.0 hr). A very high energy (VHE) gamma-ray signal was discovered with…

Astrophysics · Physics 2007-09-17 MAGIC Collaboration , M. Hayashida , K. Berger , E. Lindfors , V. Vitale , R. Wagner , E. Lorenz

Model-independent Redshift Estimation of BL Lac Objects through VHE Observations

The very high energy (VHE) gamma-ray spectral indices of blazars show strong correlation with the source redshift. Absence of any such correlation in low energy gamma rays and X-rays indicate the presence of Extragalactic Background Light…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Malik Zahoor , Sunder Sahayanathan , Shah Zahir , Naseer Iqbal , Aaqib Manzoor , Nilay Bhatt

VERITAS long term monitoring of Gamma-Ray emission from the BL Lacertae object

BL Lacertae is the prototype of the blazar subclass known as BL Lac type objects. BL Lacertae object itself is a low-frequency-peaked BL Lac(LBL). Very high energy (VHE) gamma ray emission from this source was discovered in 2005 by MAGIC…

High Energy Astrophysical Phenomena · Physics 2017-09-12 Anushka Udara Abeysekara

An optical view of extragalactic gamma-ray emitters

The Fermi Gamma-ray Observatory discovered about a thousand extragalactic sources emitting energy from 100 MeV to 100 GeV. The majority of these sources belong to the class of blazars characterized by a quasi-featureless optical spectrum…

Astrophysics of Galaxies · Physics 2017-11-02 Simona Paiano , Renato Falomo , Marco Landoni , Aldo Treves , Riccardo Scarpa

On the detectability of Lorentz invariance violation through anomalous multi-TeV $\gamma$-ray spectra of blazars

Cosmic opacity for very high-energy gamma rays ($E>10$ TeV) due to the interaction with the extragalactic background light can be strongly reduced because of possible Lorentz-violating terms in the particle dispersion relations expected,…

High Energy Astrophysical Phenomena · Physics 2015-12-16 F. Tavecchio , G. Bonnoli

Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope

Gamma-ray burst (GRB) observations at very high energies (VHE, E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that seen in blazars and plerions, in which…

Astrophysics · Physics 2008-11-26 D. Horan , R. W. Atkins , H. M. Badran , G. Blaylock , S. M. Bradbury , J. H. Buckley , K. L. Byrum , O. Celik , Y. C. K. Chow , P. Cogan , W. Cui , M. K. Daniel , I. de la Calle Perez , C. Dowdall , A. D. Falcone , D. J. Fegan , S. J. Fegan , J. P. Finley , P. Fortin , L. F. Fortson , G. H. Gillanders , J. Grube , K. J. Gutierrez , J. Hall , D. Hanna , J. Holder , S. B. Hughes , T. B. Humensky , G. E. Kenny , M. Kertzman , D. B. Kieda , J. Kildea , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , G. Maier , P. Moriarty , T. Nagai , R. A. Ong , J. S. Perkins , D. Petry , J. Quinn , M. Quinn , K. Ragan , P. T. Reynolds , H. J. Rose , M. Schroedter , G. H. Sembroski , D. Steele , S. P. Swordy , J. A. Toner , L. Valcarcel , V. V. Vassiliev , R. G. Wagner , S. P. Wakely , T. C. Weekes , R. J. White , D. A. Williams

Active Galaxies Studied with the H.E.S.S. Observatory

X-ray selected BL Lac objects dominate the population of extragalactic sources detected in the very high energy (VHE; photon energies >100GeV) gamma-ray regime with ground-based Cherenkov Telescopes. These are not the only extragalactic VHE…

High Energy Astrophysical Phenomena · Physics 2019-08-14 L. Stawarz

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

Optical spectroscopy of BL Lacertae objects. Broad lines, companion galaxies and redshift lower limits

Aims: We present optical spectroscopy of a sample of BL Lac objects, to determine their redshift, to study their broad emission line properties and to characterize their close environment. Methods: Twelve objects were observed using the ESO…

Astrophysics · Physics 2009-11-11 B. Sbarufatti , R. Falomo , A. Treves , J. Kotilainen , .