Related papers: A Spectacular VHE Gamma-Ray Outburst from PKS 2155…

Discovery of Very High Energy Gamma Rays from 1ES 1440+122

The BL Lacertae object 1ES 1440+122 was observed in the energy range from 85 GeV to 30 TeV by the VERITAS array of imaging atmospheric Cherenkov telescopes. The observations, taken between 2008 May and 2010 June and totalling 53 hours,…

High Energy Astrophysical Phenomena · Physics 2016-08-10 VERITAS Collaboration , S. Archambault , A. Archer , A. Barnacka , B. Behera , M. Beilicke , W. Benbow , K. Berger , R. Bird , M. Boettcher , J. H. Buckley , V. Bugaev , J. V Cardenzana , M. Cerruti , X. Chen , J. L. Christiansen , L. Ciupik , E. Collins-Hughes , M. P. Connolly , W. Cui , H. J. Dickinson , J. Dumm , J. D. Eisch , M. Errando , A. Falcone , S. Federici , Q. Feng , J. P. Finley , H. Fleischhack , L. Fortson , A. Furniss , G. H. Gillanders , S. Godambe , S. Griffin , S. T. Griffiths , J. Grube , G. Gyuk , N. Haakansson , D. Hanna , J. Holder , G. Hughes , C. A. Johnson , P. Kaaret , P. Kar , M. Kertzman , Y. Khassen , D. Kieda , H. Krawczynski , S. Kumar , M. J. Lang , A. S Madhavan , G. Maier , S. McArthur , A. McCann , K. Meagher , J. Millis , P. Moriarty , T. Nelson , D. Nieto , A. O'Faolain de Bhroithe , R. A. Ong , A. N. Otte , N. Park , J. S. Perkins , M. Pohl , A. Popkow , H. Prokoph , E. Pueschel , J. Quinn , K. Ragan , J. Rajotte , L. C. Reyes , P. T. Reynolds , G. T. Richards , E. Roache , G. H. Sembroski , K. Shahinyan , A. W. Smith , D. Staszak , K Sweeney , I. Telezhinsky , J. V. Tucci , J. Tyler , A. Varlotta , V. V. Vassiliev , S. P. Wakely , R. Welsing , A. Wilhelm , D. A. Williams , B. Zitzer

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

VERITAS Observations of a Very High Energy Gamma-ray Flare from the Blazar 3C 66A

The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007 - 2008 in VHE (very high energy: E > 100 GeV) gamma-rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes. An excess of…

High Energy Astrophysical Phenomena · Physics 2010-12-14 VERITAS Collaboration , V. A. Acciari , E. Aliu , T. Arlen , M. Beilicke , W. Benbow , M. Bottcher , S. M. Bradbury , J. H. Buckley , V. Bugaev , Y. Butt , K. Byrum , A. Cannon , O. Celik , A. Cesarini , Y. C. Chow , L. Ciupik , P. Cogan , W. Cui , M. K. Daniel , R. Dickherber , T. Ergin , A. Falcone , S. J. Fegan , J. P. Finley , P. Fortin , L. Fortson , A. Furniss , D. Gall , K. Gibbs , G. H. Gillanders , S. Godambe , J. Grube , R. Guenette , G. Gyuk , D. Hanna , E. Hays , 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 , A. McCann , M. McCutcheon , J. Millis , P. Moriarty , R. Mukherjee , T. Nagai , R. A. Ong , A. N. Otte , D. Pandel , J. S. Perkins , D. Petry , F. Pizlo , M. Pohl , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , E. Roache , 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 , R. G. Wagner , S. P. Wakely , J. E. Ward , T. C. Weekes , A. Weinstein , D. A. Williams , S. Wissel , M. Wood , B. Zitzer

VERITAS observations of exceptionally bright TeV flares from LS I +61$^\circ$ 303

The very-high-energy (VHE; E > 100 GeV) gamma-ray experiment, VERITAS, detected exceptionally bright flares from the high-mass X-ray binary LS I +61$^\circ$ 303 during the period October-December 2014. LS I +61$^\circ$ 303 is a known VHE…

High Energy Astrophysical Phenomena · Physics 2015-08-28 Anna O'Faolain de Bhroithe , VERITAS collaboration

Multi-wavelength observations of 3C 279 during the extremely bright gamma-ray flare in 2014 March-April

The well studied blazar 3C 279 underwent a giant $\gamma$-ray outburst in 2014 March-April. The measured $\gamma$-ray flux (1.21 $\pm$ 0.10 $\times$ 10$^{-5}$ ph cm$^{-2}$ s$^{-1}$ in 0.1-300 GeV energy range) is the highest detected from…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Vaidehi S. Paliya , S. Sahayanathan , C. S. Stalin

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

Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232 with H.E.S.S. and broadband characterisation

The blazar 1ES 1101-232 was observed with the High Energy Stereoscopic System (H.E.S.S.) of Atmospheric Cherenkov Telescopes (ACT) in 2004 and 2005, for a live time of 43 hours. VHE (E > 10^11 eV) gamma-rays were detected for the first time…

Astrophysics · Physics 2012-08-27 H. E. S. S. Collaboration , : , F. Aharonian

Discovery of Very High Energy gamma-rays from 1ES 1011+496 at z=0.212

We report on the discovery of Very High Energy (VHE) gamma-ray emission from the BL Lacertae object 1ES1011+496. The observation was triggered by an optical outburst in March 2007 and the source was observed with the MAGIC telescope from…

Astrophysics · Physics 2008-11-26 MAGIC Collaboration , J. Albert

On the correct intrinsic VHE properties of the BL Lac H 2356-309

The high-energy-peaked BL Lac H 2356-309 (z=0.165) was detected by HESS at very high energies (VHE, >100 GeV) with relatively high significance in the years 2004-2007, allowing a good determination of its gamma-ray spectrum. After…

High Energy Astrophysical Phenomena · Physics 2012-08-06 L. Costamante

Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121

Aims: Our aim is to study the production mechanism for very-high-energy (VHE; >100GeV) gamma-rays in distant active galactic nuclei (AGN) and use the observed VHE spectrum to derive limits on the Extragalactic Background Light (EBL). We…

Astrophysics · Physics 2009-04-16 HESS Collaboration , F. Aharonian

PKS 2005-489 at VHE: Four Years of Monitoring with HESS and Simultaneous Multi-wavelength Observations

VHE observations of PKS 2005-489 were made with HESS from 2004 through 2007, together with three simultaneous multi-wavelength campaigns performed with XMM-Newton and RXTE in 2004 and 2005. A strong VHE signal, ~17sigma total, is detected…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 The HESS Collaboration , F. Acero

VERITAS observations of the BL Lac 1ES 1218+304

The VERITAS collaboration reports the detection of very-high-energy (VHE) gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z=0.182. A gamma-ray signal was detected with a statistical…

High Energy Astrophysical Phenomena · Physics 2014-11-18 VERITAS Collaboration , V. A. Acciari , E. Aliu , T. Arlen , M. Beilicke , W. Benbow , S. M. Bradbury , J. H. Buckley , V. Bugaev , Y. Butt , K. L. Byrum , O. Celik , A. Cesarini , L. Ciupik , Y. C. K. Chow , P. Cogan , P. Colin , W. Cui , M. K. Daniel , T. Ergin , A. D. Falcone , S. J. Fegan , J. P. Finley , P. Fortin , L. F. Fortson , A. Furniss , G. H. Gillanders , J. Grube , R. Guenette , G. Gyuk , D. Hanna , E. Hays , J. Holder , D. Horan , C. M. Hui , T. B. Humensky , A. Imran , P. Kaaret , N. Karlsson , M. Kertzman , D. B. Kieda , J. Kildea , A. Konopelko , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , G. Maier , A. McCann , M. McCutcheon , P. Moriarty , R. Mukherjee , T. Nagai , J. Niemiec , R. A. Ong , D. Pandel , J. S. Perkins , M. Pohl , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , H. J. Rose , M. Schroedter , G. H. Sembroski , A. W. Smith , D. Steele , S. P. Swordy , J. A. Toner , L. Valcarcel , V. V. Vassiliev , R. Wagner , S. P. Wakely , J. E. Ward , T. C. Weekes , A. Weinstein , R. J. White , D. A. Williams , S. A. Wissel , M. Wood , B. Zitzer

Revisiting the TeV flare of PKS 2155-304 in 2006

Blazars, a subclass of active galactic nuclei (AGN), are known to be bright $\gamma$-ray sources, frequently exhibiting active (flaring) periods. The blazar PKS~2155-304 is a high synchrotron-peaked BL Lac object located at redshift…

High Energy Astrophysical Phenomena · Physics 2024-02-26 Hong-Bin Tan , Ruo-Yu Liu , Markus Böttcher

Gamma-Ray Spectra & Variability of the Crab Nebula Emission Observed by BATSE

We report ~ 600 days of BATSE earth-occultation observations of the total gamma-ray (30 keV to 1.7 MeV) emission from the Crab nebula, between 1991 May 24 (TJD 8400) and 1994 October 2 (TJD 9627). Lightcurves from 35-100, 100-200, 200-300,…

Astrophysics · Physics 2009-11-10 J. C. Ling , Wm. A. Wheaton

VERITAS Observations of the gamma-Ray Binary LS I +61 303

LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy gamma-rays. The system was observed over several orbital cycles (between September 2006 and February 2007) with the…

Astrophysics · Physics 2009-11-13 V. A. Acciari , M. Beilicke , G. Blaylock , S. M. Bradbury , J. H. Buckley , V. Bugaev , Y. Butt , K. L. Byrum , O. Celik , A. Cesarini , L. Ciupik , Y. C. K. Chow , P. Cogan , P. Colin , W. Cui , M. K. Daniel , C. Duke , T. Ergin , A. D. Falcone , S. J. Fegan , J. P. Finley , P. Fortin , L. F. Fortson , D. Gall , K. Gibbs , G. H. Gillanders , J. Grube R. Guenette , D. Hanna , E. Hays , J. Holder , D. Horan , S. B. Hughes , C. M. Hui , T. B. Humensky , P. Kaaret , D. B. Kieda , J. Kildea , A. Konopelko , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , K. Lee , G. Maier , A. McCann , M. McCutcheon , J. Millis , P. Moriarty , R. Mukherjee , T. Nagai , R. A. Ong , D. Pandel , J. S. Perkins , F. Pizlo , 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 , J. A. Toner , L. Valcarcel , V. V. Vassiliev , R. Wagner , S. P. Wakely , J. E. Ward , T. C. Weekes , A. Weinstein , R. J. White , D. A. Williams , S. A. Wissel , M. Wood , B. Zitzer

Multi-wavelength Observations of PG 1553+113 with HESS

Very high energy (VHE; >100 GeV) gamma-ray observations of PG 1553+113 were made with the High Energy Stereoscopic System (HESS) in 2005 and 2006. A strong signal, ~10 standard deviations, is detected by HESS during the 2 years of…

Astrophysics · Physics 2007-10-01 HESS Collaboration , W. Benbow , C. Boisson , R. Buehler , H. Sol

Discovery of very high energy gamma-ray emission from the BL Lac object PKS 0301-243 with H.E.S.S

The active galactic nucleus PKS 0301-243 (z=0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV < E < 100 GeV) by Fermi/LAT. This paper reports on the discovery of PKS 0301-243 at very high…

High Energy Astrophysical Phenomena · Physics 2015-06-17 H. E. S. S. Collaboration , A. Abramowski , F. Acero , F. Aharonian , F. Ait , A. G. Akhperjanian , E. Angüner , G. Anton , S. Balenderan , A. Balzer , A. Barnacka , Y. Becherini , J. Becker , K. Bernlöhr , E. Birsin , E. Bissaldi , J. Biteau , M. Böttcher , C. Boisson , J. Bolmont , P. Bordas , J. Brucker , F. Brun , P. Brun , T. Bulik , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , R. Chalme-Calvet , R. C. G. Chaves , A. Cheesebrough , M. Chrétien , 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 , T. Edwards , K. Egberts , P. Eger , P. Espigat , 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 , B. Giebels , J. F. Glicenstein , M. -H. Grondin , M. Grudzìnska , S. Häffner , J. D. Hague , J. Hahn , J. Harris , G. Heinzelmann , G. Henri , G. Hermann , O. Hervet , A. Hillert , J. A. Hinton , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska , C. Jahn , M. Jamrozy , M. Janiak , F. Jankowsky , I. Jung , M. A. Kastendieck , K. Katarzyński , U. Katz , S. Kaufmann , B. Khélifi , M. Kieffer , S. Klepser , D. Klochkov , W. Kluźniak , T. Kneiske , D. Kolitzus , Nu. Komin , K. Kosack , S. Krakau , 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 , R. Marx , G. Maurin , N. Maxted , M. Mayer , T. J. L. McComb , M. C. Medina , J. Méhault , U. Menzler , M. Meyer , R. Moderski , M. Mohamed , E. Moulin , T. Murach , C. L. Naumann , M. de Naurois , D. Nedbal , J. Niemiec , S. J. Nolan , L. Oakes , S. Ohm , E. de Oña 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 , H. Poon , G. Pühlhofer , M. Punch , A. Quirrenbach , S. Raab , M. Raue , A. Reimer , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , L. Rob , S. Rosier-Lees , G. Rowell , B. Rudak , C. B. Rulten , V. Sahakian , D. A. Sanchez , A. Santangelo , R. Schlickeiser , F. Schüssler , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , H. Sol , G. Spengler , F. Spies , L. 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 , M. Vorster , S. J. Wagner , P. Wagner , M. Ward , M. Weidinger , Q. Weitzel , R. White , A. Wierzcholska , P. Willmann , A. Wörnlein , D. Wouters , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin

Simultaneous observations of PKS 2155-304 with H.E.S.S., Fermi, RXTE and ATOM: spectral energy distributions and variability in a low state

We report on the first simultaneous observations that cover the optical, X-ray, and high energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 25 August and 6 September 2008,…

High Energy Astrophysical Phenomena · Physics 2009-07-22 H. E. S. S. , Fermi-LAT collaborations

Long term lightcurve of the BL Lac object 1ES 0229+200 at TeV energies

The high-frequency peaked BL Lac object 1ES 0229+200 (z = 0.14) was first detected in very high energy (VHE, E > 100 GeV) $\gamma$-rays by the H.E.S.S. (High Energy Stereoscopic System) collaboration in 2006. No flux variability was…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Gabriele Cologna , Mahmoud Mohamed , Stefan J. Wagner , Alicja Wierzcholska , Carlo Romoli , Omar Kurtanidze

The Crab Nebula super-flare in April 2011: extremely fast particle acceleration and gamma-ray emission

We report on the extremely intense and fast gamma-ray are above 100 MeV detected by AGILE from the Crab Nebula in mid-April 2011. This event is the fourth of a sequence of reported major gamma-ray flares produced by the Crab Nebula in the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 E. Striani , M. Tavani , G. Piano , I. Donnarumma , G. Pucella , V. Vittorini , A. Bulgarelli , A. Trois , C. Pittori , F. Verrecchia , E. Costa , M. Weisskopf , A. Tennant , A. Argan , G. Barbiellini , P. Caraveo , M Cardillo , P. W. Cattaneo , A. W. Chen , G. De Paris , E. Del Monte , G. Di Cocco , Y. Evangelista , A. Ferrari , M. Feroci , F. Fuschino , M. Galli , F. Gianotti , A. Giuliani , C. Labanti , I. Lapshov , F. Lazzarotto , F. Longo , M. Marisaldi , S. Mereghetti , A. Morselli , L. Pacciani , A. Pellizzoni , F. Perotti , P. Picozza , M. Pilia , M. Rapisarda , A. Rappoldi , S. Sabatini , P. Soffitta , M. Trifoglio , S. Vercellone , F. Lucarelli , P. Santolamazza , P. Giommi