Related papers: The `blazar sequence' in TeV band

Broadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016

1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like "orphan" TeV flares and a broad emission in the high-energy regime, that are difficult to interpret using conventional one-zone…

High Energy Astrophysical Phenomena · Physics 2020-07-01 MAGIC Collaboration , 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 , Z. Bosnjak , 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 Espiñeira , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , A. Fernández-Barral , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , S. Fukami , 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 , T. Inada , S. Inoue , K. Ishio , Y. Iwamura , L. Jouvin , 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 , 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 , A. Niedzwiecki , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , M. Nöthe , S. Nozaki , 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 , S. Sakurai , K. Satalecka , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , D. Strom , M. Strzys , T. Surić , M. Takahashi , 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 , Fermi-LAT Collaboration , : , M. Hayashida

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

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

A Multiwavelength Cross-Correlation Variability Study of Fermi-LAT Blazars

We carried out a multiwavelength cross-correlation analysis of a sample of 16 blazars detected by Fermi/LAT. The purpose is to investigate if there exists correlations between the distinct bands we analyze in this work. We searched for…

High Energy Astrophysical Phenomena · Physics 2013-04-19 V. Patiño-Álvarez , A. Carramiñana , L. Carrasco , V. Chavushyan

Discovery of a new TeV gamma-ray source: VER J0521+211

We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov telescope array. These observations were motivated by the discovery of a cluster of >30GeV…

High Energy Astrophysical Phenomena · Physics 2013-10-04 VERITAS Collaboration , S. Archambault , T. Arlen , T. Aune , M. Beilicke , W. Benbow , R. Bird , A. Bouvier , J. H. Buckley , V. Bugaev , K. Byrum , A. Cesarini , L. Ciupik , M. P. Connolly , W. Cui , M. Errando , A. Falcone , S. Federici , Q. Feng , J. P. Finley , L. Fortson , A. Furniss , N. Galante , D. Gall , G. H. Gillanders , S. Griffin , J. Grube , G. Gyuk , D. Hanna , J. Holder , G. Hughes , T. B. Humensky , P. Kaaret , M. Kertzman , Y. Khassen , D. Kieda , H. Krawczynski , F. Krennrich , S. Kumar , M. J. Lang , A. S Madhavan , G. Maier , P. Majumdar , S. McArthur , A. McCann , J. Millis , P. Moriarty , R. Mukherjee , A. O'Faolain de Bhroithe , R. A. Ong , A. N. Otte , N. Park , J. S. Perkins , M. Pohl , A. Popkow , H. Prokoph , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , G. T. Richards , E. Roache , D. B. Saxon , G. H. Sembroski , A. W. Smith , D. Staszak , I. Telezhinsky , M. Theiling , A. Varlotta , V. V. Vassiliev , S. Vincent , S. P. Wakely , T. C. Weekes , A. Weinstein , R. Welsing , D. A. Williams , B. Zitzer , M. Bottcher , S. J. Fegan , P. Fortin , J. P. Halpern , Y. Y. Kovalev , M. L. Lister , J. Liu , A. B. Pushkarev , P. S. Smith

We present exactly simultaneous X-ray and TeV monitoring with {\it RXTE} and HEGRA of the TeV blazar Mrk 501 during 15 days in 1998 June. After an initial period of very low flux at both wavelengths, the source underwent a remarkable flare…

Astrophysics · Physics 2009-10-31 Rita M. Sambruna

A decade of multi-wavelength observations of the TeV blazar 1ES 1215+303: Extreme shift of the synchrotron peak frequency and long-term optical-gamma-ray flux increase

Blazars are known for their variability on a wide range of timescales at all wavelengths. Most studies of TeV gamma-ray blazars focus on short timescales, especially during flares. With a decade of observations from the Fermi-LAT and…

High Energy Astrophysical Phenomena · Physics 2020-03-23 Janeth Valverde , Deirdre Horan , Denis Bernard , Stephen Fegan , A. U. Abeysekara , A. Archer , W. Benbow , R. Bird , A. Brill , R. Brose , M. Buchovecky , J. H. Buckley , J. L. Christiansen , W. Cui , A. Falcone , Q. Feng , J. P. Finley , L. Fortson , A. Furniss , A. Gent , G. H. Gillanders , C. Giuri , O. Gueta , D. Hanna , T. Hassan , O. Hervet , J. Holder , G. Hughes , T. B. Humensky , P. Kaaret , N. Kelley-Hoskins , M. Kertzman , D. Kieda , M. Krause , F. Krennrich , M. J. Lang , G. Maier , P. Moriarty , R. Mukherjee , D. Nieto , M. Nievas-Rosillo , S. O'Brien , R. A. Ong , A. N. Otte , N. Park , A. Petrashyk , K. Pfrang , A. Pichel , M. Pohl , R. R. Prado , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , D. Ribeiro , G. T. Richards , E. Roache , I. Sadeh , M. Santander , S. S. Scott , G. H. Sembroski , K. Shahinyan , R. Shang , I. Sushch , V. V. Vassiliev , A. Weinstein , R. M. Wells , P. Wilcox , A. Wilhelm , D. A. Williams , T. J Williamson , Giuliana Noto , P. G. Edwards , B. G. Piner , V. Fallah Ramazani , T. Hovatta , J. Jormanainen , E. Lindfors , K. Nilsson , L. Takalo , Y. Y. Kovalev , M. L. Lister , A. B. Pushkarev , T. Savolainen , S. Kiehlmann , W. Max-Moerbeck , A. C. S. Readhead , A. Lähteenmäki , M. Tornikoski

Constraining blazars distances with combined GeV and TeV data

Recently, a new method to constrain the distances of blazars with unknown redshift using combined observations in the GeV and TeV regimes has been developed. The underlying assumption is that the Very High Energy (VHE, E > 100 GeV) spectrum…

High Energy Astrophysical Phenomena · Physics 2011-11-04 E. Prandini , M. Mariotti , F. Tavecchio

The Fermi blazar sequence

We revisit the blazar sequence exploiting the complete, flux limited sample of blazars with known redshift detected by the Fermi satellite after 4 years of operations (the 3LAC sample). We divide the sources into gamma-ray luminosity bins,…

High Energy Astrophysical Phenomena · Physics 2017-05-31 G. Ghisellini , C. Righi , L. Costamante , F. Tavecchio

Blazar Gamma-Rays, Shock Acceleration, and the Extragalactic Background Light

The observed spectra of blazars, their intrinsic emission, and the underlying populations of radiating particles are intimately related. The use of these sources as probes of the extragalactic infrared background, a prospect propelled by…

Astrophysics · Physics 2009-11-13 Floyd W. Stecker , Matthew G. Baring , Errol J. Summerlin

Correlated Variability in Blazars

Blazars are thought to emit highly-collimated outflows, so-called jets. By their close alignment to our line of sight, relativistic beaming effects enable us to observe these jets over the whole electromagnetic spectrum up to TeV energies,…

Astrophysics · Physics 2008-08-20 Robert Wagner

Search for TeV $\gamma$--ray emission from blazar 1ES1218+304 with TACTIC telescope during March-April 2013

In this paper, we present results of TeV $\gamma$--ray observations of the high synchrotron peaked BL Lac object 1ES 1218+304 (z=0.182) with the $TACTIC$ (TeV Atmospheric Cherenkov Telescope with Imaging Camera). The observations are…

High Energy Astrophysical Phenomena · Physics 2015-06-23 K. K. Singh , K. K. Yadav , A. K. Tickoo , R. C. Rannot , P. Chandra , N. K. Agarwal , K. K. Gaur , A. Goyal , H. C. Goyal , N. Kumar , P. Marandi , M. Kothari , H. Bhatt , K. Chanchalani , N. Chouhan , V. K. Dhar , B. Ghosal , S. R. Kaul , M. K. Koul , R. Koul , K. Venugopal , C. K. Bhat , C. Borwankar , J. Bhagwan , A. C. Gupta

The luminosity function of TeV-emitting BL Lacs: observations of an HBL sample with VERITAS

High-frequency-peaked BL Lacs (HBLs) dominate the extragalactic TeV sky, with more than 50 objects detected by the current generation of TeV observatories. Still, the properties of TeV-emitting HBLs as a population are poorly understood due…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Manel Errando , VERITAS Collaboration

Multiwavelength Observations of the Blazar VER J0521+211 During an Elevated TeV Gamma-Ray State

We report on a long-lasting, elevated gamma-ray flux state from VER J0521+211 observed by VERITAS, MAGIC, and Fermi-LAT in 2013 and 2014. The peak integral flux above 200 GeV measured with the nightly-binned light curve is $(8.8 \pm 0.4)…

High Energy Astrophysical Phenomena · Physics 2022-08-10 The VERITAS Collaboration , The MAGIC Collaboration

A Search for TeV Gamma-Ray Emission from High-Peaked Flat Spectrum Radio Quasars Using the Whipple Air-Cherenkov Telescope

Blazars have traditionally been separated into two broad categories based upon their optical emission characteristics; BL Lacs, with faint or no emission lines, and flat spectrum radio quasars (FSRQs) with prominent, broad emission lines.…

Astrophysics · Physics 2008-11-26 A. D. Falcone , the VERITAS collaboration

Discovery of TeV gamma-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift

Very high-energy gamma-ray emission from PKS 0447-439 was detected with the H.E.S.S. Cherenkov telescope array in December 2009. This blazar is one of the brightest extragalactic objects in the Fermi Bright Source List and has a hard…

High Energy Astrophysical Phenomena · Physics 2015-06-15 H. E. S. S. Collaboration , : , A. Abramowski , F. Acero , A. G. Akhperjanian , G. Anton , S. Balenderan , A. Balzer , A. Barnacka , Y. Becherini , J. Becker Tjus , B. Behera , K. Bernlöhr , E. Birsin , J. Biteau , A. Bochow , C. Boisson , J. Bolmont , P. Bordas , J. Brucker , F. Brun , P. Brun , T. Bulik , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , R. C. G. Chaves , A. Cheesebrough , S. Colafrancesco , G. Cologna , J. Conrad , C. Couturier , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange , C. Deil , P. deWilt , H. J. Dickinson , A. Djannati-Ataï , W. Domainko , L. O'C. Drury , G. Dubus , K. Dutson , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat , L. Fallon , C. Farnier , S. Fegan , F. Feinstein , M. V. Fernandes , D. Fernandez , A. Fiasson , G. Fontaine , A. Förster , M. Füßling , M. Gajdus , Y. A. Gallant , T. Garrigoux , H. Gast , B. Giebels , J. F. Glicenstein , B. Glück , D. Göring , M. -H. Grondin , M. Grudzińska , S. Häffner , J. D. Hague , J. Hahn , D. Hampf , J. Harris , S. Heinz , G. Heinzelmann , G. Henri , G. Hermann , A. Hillert , J. A. Hinton , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska , C. Jahn , M. Jamrozy , I. Jung , M. A. Kastendieck , K. Katarzynski , U. Katz , S. Kaufmann , B. Khélifi , S. Klepser , D. Klochkov , W. Kluźniak , T. Kneiske , D. Kolitzus , Nu. Komin , K. Kosack , R. Kossakowski , F. Krayzel , P. P. Krüger , H. Laffon , G. Lamanna , J. Lefaucheur , M. Lemoine-Goumard , J. -P. Lenain , D. Lennarz , T. Lohse , A. Lopatin , C. -C. Lu , V. Marandon , A. Marcowith , J. Masbou , G. Maurin , N. Maxted , M. Mayer , T. J. L. McComb , M. C. Medina , J. Méhault , U. Menzler , R. Moderski , M. Mohamed , E. Moulin , C. L. Naumann , M. Naumann-Godo , M. de Naurois , D. Nedbal , N. Nguyen , J. Niemiec , S. J. Nolan , S. Ohm , E. de O\ na Wilhelmi , B. Opitz , M. Ostrowski , I. Oya , M. Panter , R. D. Parsons , M. Paz Arribas , N. W. Pekeur , G. Pelletier , J. Perez , P. -O. Petrucci , B. Peyaud , S. Pita , G. Pühlhofer , M. Punch , A. Quirrenbach , S. Raab , M. Raue , 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 , V. Sahakian , D. A. Sanchez , A. Santangelo , R. Schlickeiser , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , F. Sheidaei , J. L. Skilton , H. Sol , G. Spengler , Ł. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek , J. -P. Tavernet , R. Terrier , M. Tluczykont , C. Trichard , K. Valerius , C. van Eldik , G. Vasileiadis , C. Venter , A. Viana , P. Vincent , H. J. Völk , F. Volpe , S. Vorobiov , M. Vorster , S. J. Wagner , M. Ward , R. White , A. Wierzcholska , D. Wouters , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin , D. Pelat

X-ray Flux and Spectral Variability of Six TeV Blazars with \textit{NuSTAR}

We report the first results of timing and spectral studies of \textit{Nuclear Spectroscopic Telescope Array (NuSTAR)} observations of six TeV emitting high-frequency peaked blazars: 1ES 0347$-$121, 1ES 0414$+$009, RGB J0710$+$591, 1ES…

High Energy Astrophysical Phenomena · Physics 2018-06-06 Ashwani Pandey , Alok C. Gupta , Paul J. Wiita

Multi-TeV flaring from blazars: Markarian 421 a case study

The TeV blazar Markarian 421 underwent multi-TeV flaring during April 2004 and simultaneously observed in x-ray and TeV energies. It was observed that the TeV outbursts had no counterparts in the lower energies, which implies that this…

High Energy Astrophysical Phenomena · Physics 2016-10-10 Sarira Sahu , Luis Salvador Miranda , Subhash Rajpoot

VERITAS Observations of Six Bright, Hard-Spectrum Fermi-LAT Blazars

We report on VERITAS very-high-energy (VHE; E>100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band,…

High Energy Astrophysical Phenomena · Physics 2015-06-11 E. Aliu , S. Archambault , T. Arlen , T. Aune , M. Beilicke , W. Benbow , M. Bottcher , A. Bouvier , J. H. Buckley , V. Bugaev , A. Cesarini , L. Ciupik , E. Collins-Hughes , M. P. Connolly , W. Cui , R. Dickherber , C. Duke , J. Dumm , M. Errando , A. Falcone , S. Federici , Q. Feng , J. P. Finley , G. Finnegan , L. Fortson , A. Furniss , N. Galante , D. Gall , S. Godambe , S. Griffin , J. Grube , G. Gyuk , D. Hanna , J. Holder , H. Huan , P. Kaaret , N. Karlsson , Y. Khassen , D. Kieda , H. Krawczynski , F. Krennrich , K. Lee , A. S Madhavan , G. Maier , P. Majumdar , S. McArthur , A. McCann , P. Moriarty , R. Mukherjee , T. Nelson , A. O'Faolain de Bhroithe , 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 , D. B. Saxon , G. H. Sembroski , D. Staszak , I. Telezhinsky , G. Tesic , M. Theiling , S. Thibadeau , K. Tsurusaki , A. Varlotta , V. V. Vassiliev , S. Vincent , M. Vivier , S. P. Wakely , T. C. Weekes , A. Weinstein , R. Welsing , D. A. Williams , B. Zitzer , P. Fortin , D. Horan , M. Fumagalli , K. Kaplan , J. X. Prochaska

Hunting Star-Forming Galaxies in the Gamma-Ray Domain

Context. Star-forming galaxies emit {\gamma}rays with relatively low luminosity, but the study of their emission is no less captivating. While it is known that their {\gamma}-ray luminosity in the GeV band is strongly linked to their star…

High Energy Astrophysical Phenomena · Physics 2025-07-02 P. Kornecki , J. Biteau , C. Boisson , P. Cristofari