Related papers: The 2009 multiwavelength campaign on Mrk 421: Vari…

Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability

(Abridged) We present a detailed analysis of week-long simultaneous observations of the blazar Mrk421 at 2-60 keV X-rays (RXTE) and TeV gamma-rays (Whipple and HEGRA) in 2001. The unprecedented quality of this dataset enables us to…

Astrophysics · Physics 2008-06-16 G. Fossati , J. H. Buckley , I. H. Bond , S. M. Bradbury , D. A. Carter-Lewis , Y. C. K. Chow , W. Cui , A. D. Falcone , J. P. Finley , J. A. Gaidos , J. Grube , J. Holder , D. Horan , D. Horns , M. M. Jordan , D. B. Kieda , J. Kildea , H. Krawczynski , F. Krennrich , M. J. Lang , S. LeBohec , K. Lee , P. Moriarty , R. A. Ong , D. Petry , J. Quinn , G. H. Sembroski , S. P. Wakely , T. C. Weekes

Simultaneous multi-wavelength campaign on PKS 2005-489 in a high state

The high-frequency peaked BL Lac object PKS 2005-489 was the target of a multi-wavelength campaign with simultaneous observations in the TeV gamma-ray (H.E.S.S.), GeV gamma-ray (Fermi/LAT), X-ray (RXTE, Swift), UV (Swift) and optical (ATOM,…

High Energy Astrophysical Phenomena · Physics 2012-08-27 The H. E. S. S. Collaboration , the Fermi LAT Collaboration , : , A. Abramowski , F. Acero , F. Aharonian , A. G. Akhperjanian , G. Anton , A. Barnacka , U. Barres de Almeida , A. R. Bazer-Bachi , Y. Becherini , J. Becker , B. Behera , K. Bernlöhr , A. Bochow , C. Boisson , J. Bolmont , P. Bordas , V. Borrel , J. Brucker , F. Brun , P. Brun , T. Bulik , I. Büsching , S. Casanova , M. Cerruti , P. M. Chadwick , A. Charbonnier , R. C. G. Chaves , A. Cheesebrough , L. -M. Chounet , A. C. Clapson , G. Coignet , 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 , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat , L. Fallon , C. Farnier , S. Fegan , F. Feinstein , M. V. Fernandes , A. Fiasson , G. Fontaine , A. Förster , M. Füßling , S. Gabici , Y. A. Gallant , H. Gast , L. Gérard , D. Gerbig , B. Giebels , J. F. Glicenstein , B. Glück , P. Goret , D. Göring , J. D. Hague , D. Hampf , M. Hauser , S. Heinz , G. Heinzelmann , G. Henri , G. Hermann , J. A. Hinton , A. Hoffmann , W. Hofmann , P. Hofverberg , D. Horns , A. Jacholkowska , O. C. de Jager , C. Jahn , M. Jamrozy , I. Jung , M. A. Kastendieck , K. Katarzyński , U. Katz , S. Kaufmann , D. Keogh , M. Kerschhaggl , D. Khangulyan , B. Khélifi , D. Klochkov , W. Kluźniak , T. Kneiske , Nu. Komin , K. Kosack , R. Kossakowski , H. Laffon , G. Lamanna , J. -P. Lenain , D. Lennarz , T. Lohse , A. Lopatin , C. -C. Lu , V. Marandon , A. Marcowith , J. Masbou , D. Maurin , N. Maxted , T. J. L. McComb , M. C. Medina , J. Méhault , N. Nguyen , R. Moderski , E. Moulin , M. Naumann-Godo , M. de Naurois , D. Nedbal , D. Nekrassov , B. Nicholas , J. Niemiec , S. J. Nolan , S. Ohm , J-F. Olive , E. de Oña Wilhelmi , B. Opitz , M. Ostrowski , 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 , F. Ryde , V. Sahakian , A. Santangelo , R. Schlickeiser , F. M. Schöck , A. Schönwald , U. Schwanke , S. Schwarzburg , S. Schwemmer , A. Shalchi , M. Sikora , J. L. Skilton , H. Sol , G. Spengler , Ł. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , I. Sushch , A. Szostek , P. H. Tam , J. -P. Tavernet , R. Terrier , O. Tibolla , M. Tluczykont , K. Valerius , C. van Eldik , G. Vasileiadis , C. Venter , J. P. Vialle , A. Viana , P. Vincent , M. Vivier , H. J. Völk , F. Volpe , S. Vorobiov , M. Vorster , S. J. Wagner , M. Ward , A. Wierzcholska , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin , A. A. Abdo , M. Ackermann , M. Ajello , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , K. Bechtol , R. Bellazzini , B. Berenji , R. D. Blandford , E. Bonamente , A. W. Borgland , J. Bregeon , A. Brez , M. Brigida , P. Bruel , R. Buehler , S. Buson , G. A. Caliandro , R. A. Cameron , A. Cannon , P. A. Caraveo , S. Carrigan , J. M. Casandjian , E. Cavazzuti , C. Cecchi , Ö. Çelik , A. Chekhtman , C. C. Cheung , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi , S. Cutini , C. D. Dermer , F. de Palma , E. do Couto e Silva , P. S. Drell , R. Dubois , D. Dumora , L. Escande , C. Favuzzi , E. C. Ferrara , W. B. Focke , P. Fortin , M. Frailis , Y. Fukazawa , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , S. Germani , N. Giglietto , P. Giommi , F. Giordano , M. Giroletti , T. Glanzman , G. Godfrey , I. A. Grenier , J. E. Grove , S. Guiriec , D. Hadasch , E. Hays , D. Horan , R. E. Hughes , G. Jóhannesson , A. S. Johnson , W. N. Johnson , T. Kamae , H. Katagiri , J. Kataoka , J. Knödlseder , M. Kuss , J. Lande , L. Latronico , S. -H. Lee , F. Longo , F. Loparco , B. Lott , M. N. Lovellette , P. Lubrano , G. M. Madejski , A. Makeev , M. N. Mazziotta , W. McConville , J. E. McEnery , P. F. Michelson , T. Mizuno , C. Monte , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , T. Nakamori , S. Nishino , P. L. Nolan , J. P. Norris , E. Nuss , T. Ohsugi , A. Okumura , N. Omodei , E. Orlando , J. F. Ormes , M. Ozaki , D. Paneque , J. H. Panetta , D. Parent , V. Pelassa , M. Pepe , M. Pesce-Rollins , F. Piron , T. A. Porter , S. Rainò , R. Rando , M. Razzano , H. F. -W. Sadrozinski , D. Sanchez , A. Sander , C. Sgrò , E. J. Siskind , P. D. Smith , G. Spandre , P. Spinelli , M. S. Strickman , D. J. Suson , H. Takahashi , T. Takahashi , T. Tanaka , J. B. Thayer , J. G. Thayer , D. J. Thompson , L. Tibaldo , D. F. Torres , G. Tosti , A. Tramacere , E. Troja , T. Uehara , T. L. Usher , J. Vandenbroucke , G. Vianello , N. Vilchez , V. Vitale , A. P. Waite , P. Wang , B. L. Winer , K. S. Wood , Z. Yang , T. Ylinen , M. Ziegler

4.5 years multi-wavelength observations of Mrk 421 during the ARGO-YBJ and Fermi common operation time

We report on the extensive multi-wavelength observations of the blazar Markarian 421 (Mrk 421) covering radio to gamma-rays, during the 4.5 year period of ARGO-YBJ and Fermi common operation time, from August 2008 to February 2013. In…

High Energy Astrophysical Phenomena · Physics 2016-01-20 B. Bartoli , P. Bernardini , X. J. Bi , Z. Cao , S. Catalanotti , S. Z. Chen , T. L. Chen , S. W. Cui , B. Z. Dai , A. Damone , Danzengluobu , I. De Mitri , B. D Ettorre Piazzoli , T. Di Girolamo , G. Di Sciascio , C. F. Feng , Zhaoyang Feng , Zhenyong Feng , Q. B. Gou , Y. Q. Guo , H. H. He , Haibing Hu , Hongbo Hu , M. Iacovacci , R. Iuppa , H. Y. Jia , Labaciren , H. J. Li , C. Liu , J. Liu , M. Y. Liu , H. Lu , L. L. Ma , X. H. Ma , G. Mancarella , S. M. Mari , G. Marsella , S. Mastroianni , P. Montini , C. C. Ning , L. Perrone , P. Pistilli , P. Salvini , R. Santonico , P. R. Shen , X. D. Sheng , F. Shi , A. Surdo , Y. H. Tan , P. Vallania , S. Vernetto , C. Vigorito , H. Wang , C. Y. Wu , H. R. Wu , L. Xue , Q. Y. Yang , X. C. Yang , Z. G. Yao , A. F. Yuan , M. Zha , H. M. Zhang , L. Zhang , X. Y. Zhang , Y. Zhang , J. Zhao , Zhaxiciren , Zhaxisangzhu , X. X. Zhou , F. R. Zhu , Q. Q. Zhu

X-ray intraday variability of the TeV blazar Mrk 421 with {\it XMM-Newton}

Highly variable Markarian 421 is a bright high synchrotron energy peaked blazar showing wide featureless non-thermal spectrum making it a good candidate for our study of intraday flux and spectral variations over time. We analyse its X-ray…

High Energy Astrophysical Phenomena · Physics 2024-11-07 A Priyana Noel , Haritma Gaur , Alok C. Gupta , Alicja Wierzcholska , Michal Ostrowski , Vinit Dhiman , Gopal Bhatta

Long-term Fermi observations of Mrk 421: clues for different non-stationary processes

This paper presents the gamma-ray spectral and timing results from the long-term regular observations of Mrk 421 with the Large Area Telescope (LAT) onboard Fermi during 2008 August - 2023 August. We discerned six periods the relatively…

High Energy Astrophysical Phenomena · Physics 2025-03-05 B. Kapanadze , A. Gurchumelia , M. Aller

Multiwavelength campaign on Mrk 509. IV. Optical-UV-X-ray variability and the nature of the soft X-ray excess

We present the analysis of XMM-Newton and Swift optical-UV and X-ray observations of the Seyfert-1/QSO Mrk 509, part of an unprecedented multi-wavelength campaign, investigating the nuclear environment of this AGN. The XMM-Newton data are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Missagh Mehdipour , Graziella Branduardi-Raymont , Jelle S. Kaastra , Pierre-Olivier Petrucci , Gerard A. Kriss , Gabriele Ponti , Alexander J. Blustin , Stephane Paltani , Massimo Cappi , Rob G. Detmers , Katrien C. Steenbrugge

Multiwavelength campaign on Mrk 509. I. Variability and spectral energy distribution

(Abridged) Active galactic nuclei show a wealth of interesting physical processes, some of which are poorly understood. We want to address a number of open questions, including the location and physics of the outflow from AGN, the nature of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. S. Kaastra , P. -O. Petrucci , M. Cappi , N. Arav , E. Behar , S. Bianchi , J. Bloom , A. J. Blustin , G. Branduardi-Raymont , E. Costantini , M. Dadina , R. G. Detmers , J. Ebrero , P. G. Jonker , C. Klein , G. A. Kriss , P. Lubinski , J. Malzac , M. Mehdipour , S. Paltani , C. Pinto , G. Ponti , E. M. Ratti , R. A. N. Smith , K. C. Steenbrugge , C. P. de Vries

5.5 years multi-wavelength variability of Mrk 421: evidences of leptonic emission from the radio to TeV

Mrk 421 is a high-synchrotron-peaked blazar featuring bright and persistent GeV and TeV emission. We use the longest and densest ongoing unbiased observing campaign obtained at TeV and GeV energies during 5.5 years with the FACT telescope…

High Energy Astrophysical Phenomena · Physics 2019-10-01 Vitalii Sliusar , Axel Arbet-Engels , Dominik Baack , Matteo Balbo , Marvin Beck , Adrian Biland , Michael Blank , Thomas Bretz , Kai Bruegge , Michael Bulinski , Jens Buss , Manuel Doerr , Daniela Dorner , Dominik Elsaesser , Dorothee Hildebrand , Roman Iotov , Marc Klinger , Karl Mannheim , Dominik Neise , Maximilian Noethe , Aleksander Paravac , Wolfgang Rhode , Bernd Schleicher , Kevin Sedlaczek , Amit Shukla , Laurits Tani , Fabian Theissen , Roland Walter

X-ray Intraday Variability of the TeV Blazar Mrk 421 with {\it Chandra}

We present an extensive study of 72 archival Chandra light curves of the high-frequency-peaked type blazar Mrk 421, the first strong extragalactic object to be detected at TeV energies. Between 2000 and 2015 Mrk 421 often displayed intraday…

High Energy Astrophysical Phenomena · Physics 2018-08-22 V. Aggrawal , Ashwani Pandey , Alok C. Gupta , Zhongli Zhang , Paul J. Wiita , K. K. Yadav , S. N. Tiwari

Discovery of Spectral Variability of Markarian 421 at TeV Energies

The detection of spectral variability of the gamma-ray blazar Mrk 421 at TeV energies is reported. Observations with the Whipple Observatory 10m gamma-ray telescope taken in 2000/2001 revealed exceptionally strong and long-lasting flaring…

Astrophysics · Physics 2009-11-07 F. Krennrich , I. H. Bond , S. M. Bradbury , J. H. Buckley , D. A. Carter-Lewis , W. Cui , I. de la Calle Perez , D. J. Fegan , S. J. Fegan , J. P. Finley , J. A. Gaidos , K. Gibbs , G. H. Gillanders , T. A. Hall , A. M. Hillas , J. Holder , D. Horan , M. Jordan , M. Kertzman , D. Kieda , J. Kildea , J. Knapp , K. Kosack , M. J. Lang , S. LeBohec , P. Moriarty , D. Müller , R. A. Ong , R. Pallassini , D. Petry , J. Quinn , N. W. Reay , P. T. Reynolds , H. J. Rose , G. H. Sembroski , R. Sidwell , N. Stanton , S. P. Swordy , V. V. Vassiliev , S. P. Wakely , T. C. Weekes

Relentless multi-wavelength variability of Mrk 421 and Mrk 501

Mrk 421 and Mrk 501 are two close, bright and well-studied high-synchrotron-peaked blazars, which feature bright and persistent GeV and TeV emission. We use the longest and densest dataset of unbiased observations of these two sources,…

High Energy Astrophysical Phenomena · Physics 2021-08-19 Vitalii Sliusar , Axel Arbet-Engels , Dominik Baack , Matteo Balbo , Adrian Biland , Thomas Bretz , Jens Buss , Daniela Dorner , Laura Eisenberger , Dominik Elsaesser , Dorothee Hildebrand , Roman Iotov , Adelina Kalenski , Karl Mannheim , Alison Mitchell , Dominik Neise , Maximilian Noethe , Aleksander Paravac , Wolfgang Rhode , Bernd Schleicher , Roland Walter

The Large Flares of Mrk 421 in 2006: signature of electron acceleration and energetic budget of the jet

We present the results of a deep spectral analysis of all Swift observations of Mrk 421 between April 2006 and July 2006, when it reached its highest X-ray flux recorded until the end of 2006. We completed this data set with other…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-29 A. Tramacere

Integrated Study of X-ray Spectrum and Time Lags for HBL Mrk 421 within the Framework of the Multiple-Zone Leptonic Model

We present the timing analysis of 10 archived \XMM observations with an exposure of $>40$ ks of Markarian 421. Mrk 421 is the brightest high-frequency-peaked BL Lac object (HBL) emitting in X-rays produced by electrons accelerated in the…

High Energy Astrophysical Phenomena · Physics 2024-06-25 Wen Hu , Jia-Lai Kang , Zhen-Yi Cai , Jun-Xian Wang , Zhen-Bo Su , Guang-Cheng Xiao

Spectral Monitoring of Mrk 421 during 2004

Daily monitoring of Mrk 421 in the X-ray and TeV bands during the first half of 2004 showed rapid flaring events above an elevated base flux level, culminating from March to May 2004 at an average flux level matching the highest detected…

Astrophysics · Physics 2019-08-14 J. Grube

First detection of VHE gamma-ray emission from TXS~1515--273, study of its X-ray variability and spectral energy distribution

We report here on the first multi-wavelength (MWL) campaign on the blazar TXS 1515-273, undertaken in 2019 and extending from radio to very-high-energy gamma rays (VHE). Up until now, this blazar had not been the subject of any detailed MWL…

High Energy Astrophysical Phenomena · Physics 2021-07-21 MAGIC Collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , M. Artero , K. Asano , D. Baack , A. Babić , A. Baquero , U. Barres de Almeida , J. A. Barrio , I. Batković , J. Becerra González , W. Bednarek , L. Bellizzi , E. Bernardini , M. Bernardos , A. Berti , J. Besenrieder , W. Bhattacharyya , C. Bigongiari , A. Biland , O. Blanch , Ž. Bošnjak , G. Busetto , R. Carosi , G. Ceribella , M. Cerruti , Y. Chai , A. Chilingarian , S. Cikota , S. M. Colak , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , G. D'Amico , V. D'Elia , P. Da Vela , F. Dazzi , A. De Angelis1 , B. De Lotto , M. Delfino , J. Delgado , C. Delgado Mendez , D. Depaoli , F. Di Pierro , L. Di Venere , E. Do Souto Espiñeira , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , G. Ferrara , M. V. Fonseca , L. Font , C. Fruck , S. Fukami , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , N. Giglietto , F. Giordano , P. Gliwny , N. Godinović , J. G. Green , D. Green , D. Hadasch , A. Hahn , L. Heckmann , J. Herrera , J. Hoang , D. Hrupec , M. Hütten , T. Inada , S. Inoue , K. Ishio , Y. Iwamura , I. Jiménez , J. Jormanainen , L. Jouvin , Y. Kajiwara , M. Karjalainen , D. Kerszberg , Y. Kobayashi , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , R. López-Coto , M. López-Moya , A. López-Oramas , S. Loporchio , 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 , D. Mazin , S. Menchiari , S. Mender , S. Mićanović , D. Miceli , T. Miener , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , D. Morcuende , V. Moreno , E. Moretti , V. Neustroev , C. Nigro , K. Nilsson , K. Nishijima , K. Noda , S. Nozaki , Y. Ohtani , T. Oka , J. Otero-Santos , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , L. Pavletić , P. Peñi , C. Perennes , M. Persic , P. G. Prada Moroni , E. Prandini , C. Priyadarshi , I. Puljak , W. Rhode , M. Ribó , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , S. Sakurai , K. Satalecka , F. G. Saturni , B. Schleicher , K. Schmidt , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Spolon , A. Stamerra , D. Strom , M. Strzys , Y. Suda , T. Surić , M. Takahashi , F. Tavecchio , P. Temnikov , T. Terzić , M. Teshima , L. Tosti , S. Truzzi , A. Tutone , S. Ubach , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , S. Ventura , V. Verguilov , C. F. Vigorito , V. Vitale , I. Vovk , M. Will , C. Wunderlich , D. Zaric , E. Bissaldi , G. Bonnoli , S. Cutini , F. D'Ammando , A. Nabizadeh , A. Marchini , M. Orienti

The quiescent state broadband X-ray spectrum and variability of Mkn421

The BL Lac object Mkn~421 was observed three times by the X-ray observatory BeppoSAX in consecutive days during 1997 April and May. The source was in a quiescent state, with an average 2-10 keV flux of 9.0 x 10^(-11) erg/cm/cm/s. Flux…

Astrophysics · Physics 2007-05-23 M. Guainazzi , G. Vacanti , A. Malizia , K. S. O'Flaherty , E. Palazzi , A. N. Parmar

X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. II. Spectral Analysis and Physical Constraints

Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. The source showed a very rich phenomenology, with remarkable spectral variability. This is the second of two papers presenting the results of a thorough temporal and spectral…

Astrophysics · Physics 2009-10-31 G. Fossati , A. Celotti , M. Chiaberge , Y. H. Zhang , L. Chiappetti , G. Ghisellini , L. Maraschi , F. Tavecchio , E. Pian , A. Treves

An emergence of new polarized emission region in blazar Mrk 421 associated with X-ray flare

We report on long-term multi-wavelength monitoring of blazar Mrk~421 from 2010 to 2011. The source exhibited extreme X-ray flares in 2010. Our research group performed optical photopolarimetric follow-up observations using the Kanata…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Ryosuke Itoh , Yasushi Fukazawa , Yasuyuki T. Tanaka , Koji S. Kawabata , Katsutoshi Takaki , Kazuma Hayashi , Makoto Uemura , Takahiro Ui , Mahito Sasada , Masayuki Yamanaka , Michitoshi Yoshida

New Multiwavelength Observations of PKS 2155-304 and Implications for the Coordinated Variability Patterns of Blazars

The TeV blazar PKS 2155--304 was the subject of an intensive 2 week optical and near-infrared observing campaign in 2004 August with the CTIO 0.9m telescope. During this time, simultaneous X-ray data from RXTE were also obtained. We compare…

Astrophysics · Physics 2009-11-13 M. Angela Osterman , H. Richard Miller , Kevin Marshall , Wesley T. Ryle , Hugh Aller , Margo Aller , John P. McFarland

MWL observations of VHE blazars in 2006

In 2006 the MAGIC telescope observed the well known very high energy (VHE, > 80 GeV) blazars Mrk 421 and Mrk 501 in the course of multi-wavelength campaigns, comprising measurements in the optical, X-ray and VHE regime. MAGIC performed…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 S. Rügamer , I. Oya , M. Hayashida , D. Mazin , R. M. Wagner , J. L. Contreras , T. Bretz