Related papers: The TeV blazar Markarian 421 at the highest spatia…

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

MOJAVE: XVIII. Kinematics and Inner Jet Evolution of Bright Radio-Loud Active Galaxies

We have analyzed the parsec-scale jet kinematics of 447 bright radio-loud AGN, based on 15 GHz VLBA data obtained between 1994 August 31 and 2019 August 4. We present new total intensity and linear polarization maps obtained between 2017…

High Energy Astrophysical Phenomena · Physics 2021-12-14 M. L. Lister , D. C. Homan , K. I. Kellermann , Y. Y. Kovalev , A. B. Pushkarev , E. Ros , T. Savolainen

NuSTAR, Swift, and GROND observations of the flaring MeV blazar: PMN J0641$-$0320

MeV blazars are a sub--population of the blazar family, exhibiting larger--than--average jet powers, accretion luminosities and black hole masses. Because of their extremely hard X--ray continua, these objects are best studied in the X-ray…

High Energy Astrophysical Phenomena · Physics 2016-07-27 M. Ajello , G. Ghisellini , V. S. Paliya , D. Kocevski , G. Tagliaferri , G. Madejski , A. Rau , P. Schady , J. Greiner , F. Massaro , M. Bakolovic , R. Buehler , M. Giomi , L. Marcotulli , F. D'Ammando , D. Stern , S. E. Boggs , F. E. Christensen , W. W. Craig , C. J. Hailey , F. A. Harrison , W. W. Zhang

Monitoring TeV blazars with HAWC

The recently completed High Altitude Water Cherenkov (HAWC) gamma-ray observatory has been taking data with a partial array for more than one year and is now operating with >95% duty cycle in its full configuration. With an instantaneous…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Robert J. Lauer , Patrick W. Younk

MOJAVE. XX. Persistent Linear Polarization Structure in Parsec-scale AGN Jets

We analysed the parsec-scale linear polarization properties of 436 active galactic nuclei (AGN) based on 15 GHz polarimetric Very Long Baseline Array (VLBA) observations. We present polarization and total intensity images averaged over at…

High Energy Astrophysical Phenomena · Physics 2023-03-07 A. B. Pushkarev , M. F. Aller , H. D. Aller , D. C. Homan , Y. Y. Kovalev , M. L. Lister , I. N. Pashchenko , T. Savolainen , D. Zobnina

Long-term study of Mkn 421 with the HAGAR Array of Telescopes

Context:The HAGAR Telescope Array at Hanle, Ladakh has been regularly monitoring the nearby blazar Mkn 421 for the past 7yrs. Aims: Blazars show flux variability in all timescales across the electromagnetic spectrum. While there is abundant…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Atreyee Sinha , Amit Shukla , Lab Saha , B. S. Acharya , G. C. Anupama , P. Bhattacharya , R. J. Britto , V. R. Chitnis , T. P. Prabhu , B. B. Singh , P. R. Vishwanath

Long-term Monitoring on Mrk 501 for Its VHE gamma Emission and a Flare in October 2011

As one of the brightest active blazars in both X-ray and very high energy $\gamma$-ray bands, Mrk 501 is very useful for physics associated with jets from AGNs. The ARGO-YBJ experiment is monitoring it for $\gamma$-rays above 0.3 TeV since…

High Energy Astrophysical Phenomena · Physics 2012-09-20 YBJ Collaboration , B. Bartoli , P. Bernardini , X. J. Bi , C. Bleve , I. Bolognino , P. Branchini , A. Budano , A. K. Calabrese Melcarne , P. Camarri , Z. Cao , R. Cardarelli , S. Catalanotti , C. Cattaneo , S. Z. Chen , T. L. Chen , Y. Chen , P. Creti , S. W. Cui , B. Z. Dai , G. DAl Staiti , Danzengluobu , M. Dattoli , I. De Mitri , B. D Ettorre Piazzoli , T. Di Girolamo , X. H. Ding , G. Di Sciascio , C. F. Feng , Zhaoyang Feng , Zhenyong Feng , F. Galeazzi , E. Giroletti , Q. B. Gou , Y. Q. Guo , H. H. He , Haibing Hu , Hongbo Hu , Q. Huang , M. Iacovacci , R. Iuppa , I. James , H. Y. Jia , Labaciren , H. J. Li , J. Y. Li , X. X. Li , G. Liguori , C. Liu , C. Q. Liu , J. Liu , M. Y. Liu , H. Lu , L. L. Ma , X. H. Ma , G. Mancarella , S. M. Mari , G. Marsella , D. Martello , S. Mastroianni , P. Montini , C. C. Ning , A. Pagliaro , M. Panareo , B. Panico , L. Perrone , P. Pistilli , F. Ruggieri , P. Salvini , R. Santonico , P. R. Shen , X. D. Sheng , F. Shi , C. Stanescu , A. Surdo , Y. H. Tan , P. Vallania , S. Vernetto , C. Vigorito , B. Wang , H. Wang , C. Y. Wu , H. R. Wu , B. Xu , L. Xue , Q. Y. Yang , X. C. Yang , Z. G. Yao , A. F. Yuan , M. Zha , H. M. Zhang , Jilong Zhang , Jianli Zhang , L. Zhang , P. Zhang , X. Y. Zhang , Y. Zhang , J. Zhao , Zhaxiciren , Zhaxisangzhu , X. X. Zhou , F. R. Zhu , Q. Q. Zhu , G. Zizzi

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

Investigating Possible Correlations between Gamma-Ray and Optical Lightcurves for TeV-Detected Northern Blazars over 8 Years of Observations

Blazars are a subclass of active galactic nuclei (AGN) having relativistic jets aligned within a few degrees of our line-of-sight and form the majority of the AGN detected in the TeV regime. The Fermi-Large Area Telescope (LAT) is a…

High Energy Astrophysical Phenomena · Physics 2023-07-04 Atreya Acharyya , Alberto C. Sadun

PAGaN I: Multi-Frequency Polarimetry of AGN Jets with KVN

Active Galactic Nuclei (AGN) with bright radio jets offer the opportunity to study the structure of and physical conditions in relativistic outflows. For such studies, multi-frequency polarimetric very long baseline interferometric (VLBI)…

Astrophysics of Galaxies · Physics 2015-11-27 Jae-Young Kim , Sascha Trippe , Bong Won Sohn , Junghwan Oh , Jong-Ho Park , Sang-Sung Lee , Taeseok Lee , Daewon Kim

On the production of very high energy beamed gamma-rays in blazars

The variable flux of TeV gamma-rays detected from Mkn 421 and Mkn 501 requires the presence of high energy electrons, which could in principle produce large numbers of electron/positron pairs, leading to an electromagnetic cascade. We point…

Astrophysics · Physics 2010-11-30 W. Bednarek , J. G. Kirk , A. Mastichiadis

MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images

We present images from a long term program (MOJAVE: Monitoring of Jets in AGN with VLBA Experiments) to survey the structure and evolution of parsec-scale jet phenomena associated with bright radio-loud active galaxies in the northern sky.…

Astrophysics · Physics 2009-02-27 M. L. Lister , H. D. Aller , M. F. Aller , M. H. Cohen , D. C. Homan , M. Kadler , K. I. Kellermann , Y. Y. Kovalev , E. Ros , T. Savolainen , J. A. Zensus , R. C. Vermeulen

Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects: Superluminal Motion of Gamma-Ray Bright Blazars

We present the results of a program to monitor the structure of the radio emission in 42 $\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November…

Astrophysics · Physics 2008-11-26 Svetlana G. Jorstad , Alan P. Marscher , John R. Mattox , Ann E. Wehrle , Steven D. Bloom , Alexei V. Yurchenko

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

Rapid Multiwaveband Polarization Variability in the Quasar PKS 0420-014: Optical Emission from the Compact Radio Jet

An 11-day monitoring campaign in late 2005 reveals clear correlation in polarization between the optical emission and the region of the intensity peak (the "pseudocore") at the upstream end of the jet in 43 GHz Very Long Baseline Array…

Astrophysics · Physics 2009-11-13 Francesca D. Darcangelo , Alan P. Marscher , Svetlana G. Jorstad , Paul S. Smith , Valeri M. Larionov , Vladimir A. Hagen-Thorn , Eugenia N. Kopatskaya , G. Grant Williams , Walter K. Gear

Study of optical and gamma-ray long-term variability in blazars

Blazars, a subset of powerful active galactic nuclei, feature relativistic jets that shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here I present the results of the studies that explore gamma-ray and…

High Energy Astrophysical Phenomena · Physics 2022-10-18 Gopal Bhatta

The Parsec-Scale Structure of the Newer TeV Blazars

We expand our previous studies of the parsec-scale structure of TeV blazars by presenting first-epoch images from VLBA monitoring of ten newer TeV HBLs. All ten sources were successfully detected and imaged, and all showed a one-sided…

High Energy Astrophysical Phenomena · Physics 2015-06-17 B. Glenn Piner , Philip G. Edwards

TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission -- I. Program description and sample characterization

Aims. We introduce the TELAMON program which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate…

High Energy Astrophysical Phenomena · Physics 2024-01-15 F. Eppel , M. Kadler , J. Heßdörfer , P. Benke , L. Debbrecht , J. Eich , A. Gokus , S. Hämmerich , D. Kirchner , G. F. Paraschos , F. Rösch , W. Schulga , J. Sinapius , P. Weber , U. Bach , D. Dorner , P. G. Edwards , M. Giroletti , A. Kraus , O. Hervet , S. Koyama , T. P. Krichbaum , K. Mannheim , E. Ros , M. Zacharias , J. A. Zensus

VLBI radio structure and radio brightening of the high-energy neutrino emitting blazar TXS 0506+056

We report on the radio brightening of the blazar TXS 0506+056 (at $z=0.3365$), supporting its identification as source of the high-energy (HE) neutrino IC-170922A by the IceCube Neutrino Observatory. MOJAVE/VLBA data indicate its radio…

High Energy Astrophysical Phenomena · Physics 2018-12-05 E. Kun , P. L. Biermann , L. Á. Gergely

The Aftermath of an Exceptional TeV Flare in the AGN Jet of IC 310

The nearby active galaxy IC 310 (z=0.019), located in the Perseus cluster of galaxies is a bright and variable multi-wavelength emitter from the radio regime up to very high gamma-ray energies above 100 GeV. Very recently, a blazar-like…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Dorit Eisenacher , Pierre Colin , Saverio Lombardi , Julian Sitarek , Fabio Zandanel , Francisco Prada , Elina Linfors , David Paneque , Dominik Elsässer , Karl Mannheim , Cornelia Müller , Thomas Dauser , Felicia Krauß , Sven Wilbert , Matthias Kadler , Jörn Wilms , Uwe Bach , Eduardo Ros , Talvikki Hovatta , Tuomas Savolainen