Related papers: Extreme Blazars Observed with MAGIC: Second Catalo…

MAGIC observations of the February 2014 flare of 1ES 1011+496 and ensuing constraint of the EBL density

In February-March 2014, the MAGIC telescopes observed the high-frequency peaked BL Lac 1ES 1011+496 (z=0.212) in flaring state at very-high energy (VHE, E>100GeV). The flux reached a level more than 10 times higher than any previously…

High Energy Astrophysical Phenomena · Physics 2016-05-04 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. Bil , 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 , B. De Lotto , E. de O na Wilhelmi , C. Delgado Mendez , F. Di Pierro , 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. Godinovic , A. González Muñoz , D. Guberman , 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 , A. López-Oramas , E. Lorenz , 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. Mira , R. Mirzoyan , A. Moralejo , E. Moretti , D. Nakajima , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , K. Nilsson , K. Nishijima , K. Noda , 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. Prini , I. Puljak , W. Rhode , M. Ribó , J. Rico , J. Rodriguez Garcia , T. Saito , K. Satalecka , 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 , J. E. Ward , M. Will , M. H. Wu , R. Zanin

Synchrotron pair halo and echo emission from blazars in the cosmic web: application to extreme TeV blazars

High frequency peaked high redshift blazars, are extreme in the sense that their spectrum is particularly hard and peaks at TeV energies. Standard leptonic scenarios require peculiar source parameters and/or a special setup in order to…

High Energy Astrophysical Phenomena · Physics 2014-09-03 Foteini Oikonomou , Kohta Murase , Kumiko Kotera

Multiwavelength modeling of TeV AGN observed by HESS

The High Energy Stereoscopic System (H.E.S.S.) experiment, a ground-based gamma-ray Cherenkov telescope array located in Namibia, has now detected many extragalactic objects, which redshifts range from z=0.00183 up to z=0.2, possibly more.…

Astrophysics · Physics 2007-09-12 Jean-Philippe Lenain

TeV gamma-ray observations of southern BL Lacs with the CANGAROO 3.8m Imaging Telescope

Observational and theoretical results indicate that low-redshift BL Lacertae objects are the most likely extragalactic sources to be detectable at TeV energies. In this paper we present the results of observations of 4 BL Lacertae objects…

Astrophysics · Physics 2011-04-04 M. D. Roberts , S. A. Dazeley , P. G. Edwards , T. Hara , Y. Hayami , J. Holder , F. Kakimoto , S. Kamei , A. Kawachi , T. Kifune , R. Kita , T. Konishi , A. Masaike , Y. Matsubara , T. Matsuoka , Y. Mizumoto , M. Mori , H. Muraishi , Y. Muraki , K. Nishijima , S. Oda , S. Ogio , J. R. Patterson , G. P. Rowell , T. Sako , K. Sakurazawa , R. Susukita , A. Suzuki , R. Suzuki , T. Tamura , T. Tanimori , G. J. Thornton , S. Yanagita , T. Yoshida , T. Yoshikoshi

Detecting the Attenuation of Blazar Gamma-ray Emission by Extragalactic Background Light with GLAST

Gamma rays with energy above 10 GeV interact with optical-UV photons resulting in pair production. Therefore, a large sample of high redshift sources of these gamma rays can be used to probe the extragalactic background starlight (EBL) by…

Astrophysics · Physics 2009-11-10 Andrew Chen , Luis C. Reyes , Steven Ritz

Exploring the High-Energy Gamma-Ray Spectra of TeV Blazars

The highest-energy blazars exhibit non-thermal radiation extending beyond 1 TeV with high luminosities and strong variabilities, indicating extreme particle acceleration in their relativistic jets. The gamma-ray spectra of blazars contain…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Qi Feng

ANTARES search for high-energy neutrinos from TeV-emitting blazars, Markarian 421 and 501, in coincidence with HAWC gamma-ray flares

An updated analysis of a targeted search for high-energy neutrinos from Markarian 421 and Markarian 501 is reported. They are two of the closest and brightest extragalactic sources in the TeV band. In contrast to other types of active…

High Energy Astrophysical Phenomena · Physics 2019-11-13 Mukharbek Organokov , Thierry Pradier

Variability along the Blazar-Sequence - Hints for extragalactic Cosmic Rays?

The spectral energy distribution and variability of several blazars (Mkn 501, 1 ES 2344+51.4, PKS 2155-30.4, 1 ES 1218+30.4, 3C 454.3) along the blazar sequence is investigated using a selfconsistent and timedependent lepto-hadronic hybrid…

High Energy Astrophysical Phenomena · Physics 2011-09-12 Matthias Weidinger , Felix Spanier

A thirteen-year-long broadband view of BL Lac

We present the results of an extensive analysis of the optical, ultraviolet, X-ray and $\gamma$-ray data collected from the observations of the BL Lac objects prototype BL Lacertae carried out over a period of nearly 13 years, between…

High Energy Astrophysical Phenomena · Physics 2022-04-20 N. Sahakyan , P. Giommi

Target of Opportunity observations of blazars with H.E.S.S.$\ $

The very high energy (VHE, E > 100 GeV) sky is dominated by blazars, radio-loud active galactic nuclei whose relativistic jet is closely aligned with the line of sight. Blazars are characterized by rapid variability at all wavelengths and…

High Energy Astrophysical Phenomena · Physics 2017-08-09 M. Cerruti , M. Böttcher , N. Chakraborty , I. D. Davids , M. Füßling , F. Jankowsky , J. P. Lenain , M. Meyer , H. Prokoph , S. Wagner , D. Zaborov , M. Zacharias , the H. E. S. S. Collaboration

MAGIC discovery of VHE Emission from the FSRQ PKS 1222+21

Very High Energy (VHE) gamma-ray emission from the flat spectrum radio quasar (FSRQ) PKS 1222+21 (4C 21.35, z=0.432) was detected with the MAGIC Cherenkov telescopes during a short observation (~0.5 hr) performed on 2010 June 17. The MAGIC…

High Energy Astrophysical Phenomena · Physics 2011-03-07 J. Aleksić , L. Antonelli , P. Antoranz , M. Backes , J. Barrio , D. Bastieri , J. Becerra González , W. Bednarek , A. Berdyugin , K. Berger , E. Bernardini , A. Biland , O. Blanch , R. Bock , A. Boller , G. Bonnoli , D. Borla Tridon , I. Braun , Dr. Thomas Bretz , A. Cañellas , E. Carmona , A. Carosi , P. Colin , E. Colombo , J. Contreras , J. Cortina , L. Cossio , S. Covino , F. Dazzi , A. De Angelis , E. De Cea del Pozo , Dr. Barbara De Lotto , Dr. Carlos Delgado Mendez , A. Diago Ortega , M. Doert , A. Domìnguez , D. Dominis Prester , D. Dorner , M. Doro , D. Elsaesser , D. Ferenc , M. Fonseca , L. Font , C. Fruck , R. Garcìa Lòpez , 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 , S. Klepser , T. Krahenbuhl , J. Krause , A. La Barbera , D. Lelas , E. Leonardo , E. Lindfors , S. Lombardi , M. López , E. Lorenz , M. Makariev , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , M. Mariotti , M. Martínez , Dr. Daniel Mazin , M. Meucci , J. Miranda , R. Mirzoyan , H. Miyamoto , Mr. Javier Moldón , A. Moralejo , D. Nieto , Dr. Kari Nilsson , R. Orito , I. Oya , D. Paneque , R. Paoletti , S. Pardo , J. Paredes , S. Partini , M. Pasanen , F. Pauss , M. Perez-Torres , Dr. Massimo Persic , L. Peruzzo , M. Pilia , J. Pochon , F. Prada , Dr. P. G. Prada Moroni , E. Prandini , I. Puljak , I. Reichardt , R. Reinthal , W. Rhode , Marc Ribó , Dr. Javier Rico , S. Rügamer , A. Saggion , Mr. Koji Saito , T. Saito , M. Salvati , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , M. Shayduk , S. Shore , A. Sillanpää , J. Sitarek , D. Sobczynska , F. Spanier , S. Spiro , A. Stamerra , B. Steinke , J. Storz , N. Strah , T. Surić , L. Takalo , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , M. Thom , O. Tibolla , Dr. Miguel-Angel Perez-Torres , A. Treves , H. Vankov , P. Vogler , R. Wagner , Q. Weitzel , V. Zabalza , F. Zandanel , R. Zanin , Y. Tanaka , D. Wood , S. Buson

Multiwavelength Observations of the Previously Unidentified Blazar RX J0648.7+1516

We report on the VERITAS discovery of very-high-energy (VHE) gamma- ray emission above 200 GeV from the high-frequency-peaked BL Lac object RXJ0648.7+1516 (GBJ0648+1516), associated with 1FGLJ0648.8+1516. The photon spectrum above 200 GeV…

High Energy Astrophysical Phenomena · Physics 2015-05-30 E. Aliu , T. Aune , M. Beilicke , W. Benbow , M. Böttcher , A. Bouvier , S. M. Bradbury , J. H. Buckley , V. Bugaev , A. Cannon , A. Cesarini , L. Ciupik , M. P. Connolly , W. Cui , G. Decerprit , R. Dickherber , C. Duke , M. Errando , A. Falcone , Q. Feng , G. Finnegan , L. Fortson , A. Furniss , N. Galante , D. Gall , G. H. Gillanders , S. Godambe , S. Griffin , J. Grube , G. Gyuk , D. Hanna , B. Hivick , J. Holder , H. Huan , G. Hughes , C. M. Hui , T. B. Humensky , P. Kaaret , N. Karlsson , M. Kertzman , D. Kieda , H. Krawczynski , F. Krennrich , G. Maier , P. Majumdar , S. McArthur , A. McCann , P. Moriarty , R. Mukherjee , T. Nelson , R. A. Ong , M. Orr , A. N. Otte , N. Park , J. S. Perkins , A. Pichel , M. Pohl , H. Prokoph , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , E. Roache , H. J. Rose , J. Ruppel , D. B. Saxon , G. H. Sembroski , C. Skole , A. W. Smith , D. Staszak , G. Tesic , M. Theiling , S. Thibadeau , K. Tsurusaki , J. Tyler , A. Varlotta , V. V. Vassiliev , S. P. Wakely , T. C. Weekes , A. Weinstein , D. A. Williams , B. Zitzer , S. Ciprini , M. Fumagalli , K. Kaplan , D. Paneque , J. X. Prochaska

The Extragalactic Background Light and the Gamma-ray Opacity of the Universe

The extragalactic background light (EBL) is one of the fundamental observational quantities in cosmology. All energy releases from resolved and unresolved extragalactic sources, and the light from any truly diffuse background, excluding the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Eli Dwek , Frank Krennrich

A multiwavelength view of BL Lacs neutrino candidates

The discovery of high-energy astrophysical neutrinos by IceCube kicked off a new line of research to identify the electromagnetic counterparts producing these neutrinos. Among the extragalactic sources, active galactic nuclei (AGN), and in…

High Energy Astrophysical Phenomena · Physics 2019-02-13 C. Righi , F. Tavecchio , L. Pacciani

HEGRA search for TeV emission from BL Lac objects

The HEGRA system of four Imaging Atmospheric Cherenkov Telescopes (IACTs) has been used to extensively observe extragalactic objects. In this paper we describe the search for TeV emission from nine very promising potential TeV sources,…

Astrophysics · Physics 2007-05-23 F. Aharonian , The HEGRA Collaboration

Discovery of VHE and HE emission from the blazar 1ES 0414+009 with H.E.S.S and Fermi-LAT

The high energy peaked BL Lac (HBL) object 1ES 0414+009 (z=0.287) is a distant very high-energy (VHE, E > 100 GeV) blazars with well-determined redshift. This source was detected with the High Energy Stereoscopic System (H.E.S.S.) between…

High Energy Astrophysical Phenomena · Physics 2011-05-26 F. Volpe , S. Ohm , M. Hauser , S. Kaufmann , L. Gérard , L. Costamante , S. Fegan , M. Ajello

Multiwavelength observations of the blazar BL Lacertae: a new fast TeV gamma-ray flare

Combined with very-long-baseline interferometry measurements, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and…

High Energy Astrophysical Phenomena · Physics 2018-06-08 A. U. Abeysekara , W. Benbow , R. Bird , T. Brantseg , R. Brose , M. Buchovecky , J. H. Buckley , V. Bugaev , M. P. Connolly , W. Cui , M. K. Daniel , A. Falcone , Q. Feng , J. P. Finley , L. Fortson , A. Furniss , G. H. Gillanders , I. Gunawardhana , M. Hütten , D. Hanna , O. Hervet , J. Holder , G. Hughes , T. B. Humensky , C. A. Johnson , P. Kaaret , P. Kar , M. Kertzman , F. Krennrich , M. J. Lang , T. T. Y. Lin , S. McArthur , P. Moriarty , R. Mukherjee , S. O'Brien , R. A. Ong , A. N. Otte , N. Park , A. Petrashyk , M. Pohl , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , G. T. Richards , E. Roache , C. Rulten , I. Sadeh , M. Santander , G. H. Sembroski , K. Shahinyan , S. P. Wakely , A. Weinstein , R. M. Wells , P. Wilcox , D. A. Williams , B. Zitzer , S. G. Jorstad , A. P. Marscher , M. L. Lister , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen , I. Agudo , S. N. Molina , J. L. Gómez , V. M. Larionov , G. A. Borman , A. A. Mokrushina , M. Tornikoski , A. Lähteenmäki , W. Chamani , S. Enestam , S. Kiehlmann , T. Hovatta , P. S. Smith , P. Pontrelli

Contribution to the Extragalactic Gamma-ray Background from the Cascades of Very-high Energy Gamma Rays from Blazars

As very high energy (VHE) photons propagate through the extragalactic background light (EBL), they interact with the soft photons and initiate electromagnetic cascades of lower energy photons and electrons. The collective intensity of a…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Tonia M. Venters

Discovery of VHE gamma-rays from the high-frequency-peaked BL Lac object RGB J0152+017

Aims: The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; > 100 GeV) gamma-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by investigating the observed…

Astrophysics · Physics 2008-04-09 HESS Collaboration , F. Aharonian

Study of long-term spectral evolution and X-ray and Gamma-ray correlation of blazars seen by HAWC

The HAWC Observatory collected 6 years of extensive data, providing an ideal platform for long-term monitoring of blazars in the Very High Energy (VHE) band, without bias towards specific flux states. HAWC continuously monitors blazar…

High Energy Astrophysical Phenomena · Physics 2025-01-28 R. Alfaro , C. Alvarez , A. Andrés , J. C. Arteaga-Velázquez , D. Avila Rojas , H. A. Ayala Solares , R. Babu , E. Belmont-Moreno , A. Bernal , K. S. Caballero-Mora , T. Capistrán , A. Carramiñana , F. Carreón , S. Casanova , U. Cotti , J. Cotzomi , S. Coutiño de León , E. De la Fuente , D. Depaoli , N. Di Lalla , R. Diaz Hernandez , B. L. Dingus , M. A. DuVernois , M. Durocher , J. C. Díaz-Vélez , K. Engel , C. Espinoza , K. L. Fan , N. Fraija , S. Fraija , J. A. García-González , F. Garfias , A. Gonzalez Muñoz , M. M. González , J. A. Goodman , S. Groetsch , J. P. Harding , S. Hernández-Cadena , I. Herzog , D. Huang , F. Hueyotl-Zahuantitla , A. Iriarte , V. Joshi , S. Kaufmann , D. Kieda , A. Lara , W. H. Lee , J. Lee , H. León Vargas , J. T. Linnemann , A. L. Longinotti , G. Luis-Raya , K. Malone , O. Martinez , I. Martinez-Castellanos , J. Martínez-Castro , J. A. Matthews , P. Miranda-Romagnoli , J. A. Montes , E. Moreno , M. Mostafá , A. Nayerhoda , L. Nellen , M. U. Nisa , R. Noriega-Papaqui , N. Omodei , M. Osorio , Y. Pérez Araujo , E. G. Pérez-Pérez , C. D. Rho , D. Rosa-González , E. Ruiz-Velasco , H. Salazar , D. Salazar-Gallegos , A. Sandoval , M. Schneider , J. Serna-Franco , A. J. Smith , Y. Son , R. W. Springer , O. Tibolla , K. Tollefson , I. Torres , R. Torres-Escobedo , R. Turner , F. Ureña-Mena , E. Varela , L. Villaseñor , X. Wang , I. J. Watson , K. Whitaker , E. Willox , S. Yun-Cárcamo , H. Zhou , C. de León , Abraham D. Falcone , Fredric Hancock