Related papers: Characterizing the VHE emission of LS I +61 303 us…

Discovery of the Binary Pulsar PSR B1259-63 in Very-High-Energy Gamma Rays around Periastron with H.E.S.S

We report the discovery of very-high-energy (VHE) gamma-ray emission of the binary system PSR B1259-63/SS 2883 of a radio pulsar orbiting a massive, luminous Be star in a highly eccentric orbit. The observations around the 2004 periastron…

Astrophysics · Physics 2009-11-11 F. Aharonian

On the X-ray/TeV connection in Galactic jet sources

There are three Galactic jet sources, from which TeV emission has been detected: LS 5039, LS I +61 303 and Cygnus X-1. These three sources show power-law tails at X-rays and soft gamma-rays that could indicate a non-thermal origin for this…

Astrophysics · Physics 2011-03-10 V. Bosch-Ramon , D. Khangulyan , F. A. Aharonian

Serendipitous discovery of the unidentified extended TeV gamma-ray source HESS J1303-631

The serendipitous discovery of an unidentified extended TeVgamma-ray source close to the galactic plane named HESS J1303-631 at a significance of 21 standard deviations is reported. The observations were performed between February and June…

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

XMM-Newton Observations of the TeV \gamma-ray Source HESS J1804-216

We have analyzed three XMM-Newton observations of the central part of the unidentified TeV \gamma-ray source HESS J1804-216. We focus on two X-ray sources 2XMMi J180442.0-214221 (Src 1) and 2XMMi J180432.5-214009 (Src 2), which were…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Dacheng Lin , Natalie A. Webb , Didier Barret

Chandra Observation of the Unidentified TeV Gamma-Ray Source HESS J1303-631 in the Galactic Plane

The imaging atmospheric Cherenkov array H.E.S.S. recently discovered an extended source in the 0.4$-$10 TeV energy range, HESS J1303-631. We obtained a 5 ks observation with the ACIS-I array on the Chandra X-ray observatory that does not…

Astrophysics · Physics 2009-11-11 R. Mukherjee , J. P. Halpern

VERITAS Observations of the Unidentified Point Source HESS J1943+213

The H.E.S.S. Galactic plane scan has revealed a large population of Galactic very high energy (VHE; E > 100 GeV) emitters. The majority of the galactic sources are extended and can typically be associated with pulsar wind nebulae (35%) and…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Karlen Shahinyan

Very High Energy Gamma-ray spectral properties of Mrk 501 from CAT Cerenkov telescope observations in 1997

The BL Lac object Mrk 501 went into a very high state of activity during 1997, both in VHE gamma-rays and X-rays. We present here results from observations at energies above 250 GeV carried out between March and October 1997 with the CAT…

Astrophysics · Physics 2007-05-23 A. Djannati-Atai , F. Piron , A. Barrau , L. Iacoucci , M. Punch , J. -P. Tavernet , R. Bazer-Bachi , H. Cabot , L. -M. Chounet , G. Debiais , B. Degrange , J. -P. Dezalay , D. Dumora , P. Espigat , B. Fabre , P. Fleury , G. Fontaine , C. Ghesquière , P. Goret , C. Gouiffes , I. A. Grenier , S. Le Bohec , I. Malet , C. Meynadier , G. Mohanty , E. Nuss , E. Paré , J. Québert , K. Ragan , C. Renault , M. Rivoal , L. Rob , K. Schahmaneche , D. A. Smith

Searches for TeV emission from Northern Hemisphere pulsars with VERITAS

The discovery of VHE emission from the Crab pulsar and, more recently, multi-TeV emission from the Vela pulsar have challenged our current understanding of the emission mechanisms of these sources. Studying pulsar emission at TeV energies…

High Energy Astrophysical Phenomena · Physics 2025-09-24 Samantha Wong , Dinah Ibrahim , Benjamin Shaw

The Orbits of the Gamma-ray Binaries LS I +61 303 and LS 5039

LS I +61 303 and LS 5039 are two of only a handful of known high mass X-ray binaries (HMXBs) that exhibit very high energy emission in the MeV-TeV range, and these "gamma-ray binaries" are of renewed interest due to the recent launch of the…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Christina Aragona , M. Virginia McSwain , Erika D. Grundstrom , Amber N. Marsh , Rachael M. Roettenbacher , Katelyn M. Hessler , Tabetha S. Boyajian , Paul S. Ray

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

Role of the disk environment in the gamma-ray emission from the binary system PSR B1259-63/LS 2883

PSR B1259-63/LS 2883 is a very high energy (VHE; E > 100 GeV) gamma-ray emitting binary consisting of a 48 ms pulsar orbiting around a Be star with a period of 3.4 years. The Be star features a circumstellar disk which is inclined with…

High Energy Astrophysical Phenomena · Physics 2015-09-07 Iurii Sushch , Markus Böttcher

VERITAS observations of M87 from 2007 to present

M87 is a nearby radio galaxy and because of its misaligned jet, it is possible to correlate detailed spatially-resolved emission regions in the radio, optical to X-ray waveband with unresolved but contemporaneous flux measurements in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 C. M. Hui

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

The TeV emission of 3C273: inverse Compton radiation from shear-accelerated high-energy electrons in the large-scale jet?

The VERITAS Collaboration recently reported the detection of very-high-energy (VHE) gamma-ray emission from the prototypical radio quasar 3C273. The temporal and the spectral properties of this component do not appear compatible with the…

High Energy Astrophysical Phenomena · Physics 2025-11-07 F. Tavecchio

Discovery of Variability in the Very High Energy Gamma-Ray Emission of 1ES 1218+304 with VERITAS

We present results from an intensive VERITAS monitoring campaign of the high-frequency peaked BL Lac object 1ES 1218+304 in 2008/2009. Although 1ES 1218+304 was detected previously by MAGIC and VERITAS at a persistent level of ~6% of the…

High Energy Astrophysical Phenomena · Physics 2010-01-18 The VERITAS Collaboration , V. A. Acciari , E. Aliu , M. Beilicke , W. Benbow , D. Boltuch , M. Böttcher , S. M. Bradbury , V. Bugaev , K. Byrum , A. Cesarini , L. Ciupik , P. Cogan , W. Cui , R. Dickherber , C. Duke , A. Falcone , J. P. Finley , G. Finnegan , L. Fortson , A. Furniss , N. Galante , D. Gall , K. Gibbs , R. Guenette , G. H. Gillanders , S. Godambe , J. Grube , D. Hanna , C. M. Hui , T. B. Humensky , A. Imran , P. Kaaret , N. Karlsson , M. Kertzman , D. Kieda , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , G. Maier , S. McArthur , A. McCann , P. Moriarty , T. Nagai , R. A. Ong , A. N. Otte , D. Pandel , J. S. Perkins , A. Pichel , 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 , S. Thibadeau , V. V. Vassiliev , S. Vincent , S. P. Wakely , T. C. Weekes , A. Weinstein , T. Weisgarber , D. A. Williams

Detection of VHE \gamma-rays from HESS J0632+057 during the 2011 February X-ray outburst with the MAGIC Telescopes

The very high energy (VHE) \gamma-ray source HESS J0632+057 has recently been confirmed to be a \gamma-ray binary. The optical counterpart is the Be star MWC 148, and a compact object of unknown nature orbits it every ~321 d with a high…

High Energy Astrophysical Phenomena · Physics 2019-08-12 The MAGIC Collaboration , J. Aleksić , E. A. Alvarez , L. A. Antonelli , P. Antoranz , 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 , V. Bosch-Ramon , 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

VERITAS Observations of the BL Lac Object 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 high statistical…

Astrophysics · Physics 2019-08-13 Pascal Fortin

Rapid TeV Gamma-Ray Flaring of BL Lacertae

We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6-minute exposure,…

High Energy Astrophysical Phenomena · Physics 2015-06-12 T. Arlen , T. Aune , M. Beilicke , W. Benbow , A. Bouvier , J. H. Buckley , V. Bugaev , A. Cesarini , L. Ciupik , M. P. Connolly , W. Cui , R. Dickherber , J. Dumm , M. Errando , A. Falcone , S. Federici , Q. Feng , J. P. Finley , G. Finnegan , L. Fortson , A. Furniss , N. Galante , D. Gall , S. Griffin , J. Grube , G. Gyuk , D. Hanna , J. Holder , T. B. Humensky , P. Kaaret , N. Karlsson , M. Kertzman , Y. Khassen , D. Kieda , H. Krawczynski , F. Krennrich , G. Maier , P. Moriarty , R. Mukherjee , T. Nelson , A. O'Faolain de Bhroithe , R. A. Ong , M. Orr , 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 , M. Schroedter , G. H. Sembroski , D. Staszak , I. Telezhinsky , G. Tesic , M. Theiling , K. Tsurusaki , A. Varlotta , S. Vincent , S. P. Wakely , T. C. Weekes , A. Weinstein , R. Welsing , D. A. Williams , B. Zitzer , S. G. Jorstad , N. R. MacDonald , A. P. Marscher , P. S. Smith , R. C. Walker , T. Hovatta , J. Richards , W. Max-Moerbeck , A. Readhead , M. L. Lister , Y. Y. Kovalev , A. B. Pushkarev , M. A. Gurwell , A. Lahteenmaki , E. Nieppola , M. Tornikoski , E. Jarvela

VERITAS discovery of very high energy gamma-ray emission from S3 1227+25 and multiwavelength observations

We report the detection of very high energy gamma-ray emission from the blazar S3 1227+25 (VER J1230+253) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). VERITAS observations of the source were triggered by the…

High Energy Astrophysical Phenomena · Physics 2023-06-21 Atreya Acharyya , Colin Adams , Avery Archer , Priyadarshini Bangale , Wystan Benbow , Aryeh Brill , Jodi Christiansen , Alisha Chromey , Manel Errando , Abe Falcone , Qi Feng , John Finley , Gregory Foote , Lucy Fortson , Amy Furniss , Greg Gallagher , William Hanlon , David Hanna , Olivier Hervet , Claire Hinrichs , John Hoang , Jamie Holder , Weidong Jin , Madalyn Johnson , Philip Kaaret , Mary P. Kertzman , David Kieda , Tobias Kleiner , Nikolas Korzoun , Frank Krennrich , Mark Lang , Matthew Lundy , Gernot Maier , Conor McGrath , Matthew Millard , John Millis , Connor Mooney , Patrick Moriarty , Reshmi Mukherjee , Stephan O'Brien , Rene A. Ong , Martin Pohl , Elisa Pueschel , John Quinn , Kenneth J. Ragan , Paul Reynolds , Deivid Ribeiro , Emmet Thomas Roache , Iftach Sadeh , Alberto Sadun , Lab Saha , Marcos Santander , Glenn Sembroski , Ruo Shang , Megan Splettstoesser , Anjana Talluri , James Tucci , Vladimir Vassiliev , David Williams , Sam Wong , Talvikki Hovatta , Svetlana Jorstad , Sebastian Kiehlmann , Anne Lahteenmaki , Ioannis Liodakis , Alan Marscher , Walter Max-Moerbeck , Anthony Readhead , Rodrigo Reeves , Paul S Smith , Merja Tornikoski

GeV Emission from TeV Blazars and Intergalactic Magnetic Fields

Several high-frequency peaked BL Lac objects such as Mrk 501 are strong TeV emitters. However, a significant fraction of the TeV gamma rays emitted are likely to be absorbed in interactions with the diffuse IR background, yielding…

Astrophysics · Physics 2009-11-07 Z. G. Dai , B. Zhang , L. J. Gou , P. Meszaros , E. Waxman