Related papers: Variable VHE gamma-ray emission from Markarian 501

Simultaneous X-Ray and TeV Gamma-Ray Observations of the TeV Blazar Markarian 421 during February and May 2000

In this paper we present the results of simultaneous observations of the TeV blazar Markarian 421 (Mrk 421) at X-ray and TeV Gamma-ray energies with the Rossi X-Ray Timing Explorer (RXTE) and the stereoscopic Cherenkov Telescope system of…

Astrophysics · Physics 2009-11-06 H. Krawczynski , R. Sambruna , A. Kohnle , P. S. Coppi , The HEGRA Collaboration , F. Aharonian

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

Markarian 501 in X-ray bright state - RXTE observations

Mrk 501 has been in a state of very high flux in X-rays and VHE gamma-rays during 1997. In July 1997 near its hitherto maximum X-ray brightness intense multifrequency observations of Mrk 501 have been performed at radio, near infrared,…

Astrophysics · Physics 2016-08-30 G. Lamer , S. J. Wagner

Temporal and spectral gamma-ray properties of Mkn421 above 250 GeV from CAT observations between 1996 and 2000

The gamma-ray emission above 250 GeV from the BL Lac object Markarian 421 was observed by the CAT Cherenkov imaging telescope between December, 1996, and June, 2000. In 1998, the source produced a series of small flares, making it the…

Astrophysics · Physics 2014-10-13 F. Piron , A. Djannati-Atai , M. Punch , J. -P. Tavernet , A. Barrau , R. Bazer-Bachi , L. -M. Chounet , G. Debiais , B. Degrange , J. -P. Dezalay , P. Espigat , B. Fabre , P. Fleury , G. Fontaine , P. Goret , C. Gouiffes , B. Khelifi , I. Malet , C. Masterson , G. Mohanty , E. Nuss , C. Renault , M. Rivoal , L. Rob , S. Vorobiov

EBL effect on the observation of multi-TeV flaring of 2009 from Markarian 501

Markarian 501 is a high-peaked BL Lacertae object and has undergone many major outburst since its discovery in 1996. As a part of the multiwavelength campaign, in the year 2009 this blazar was observed for 4.5 months from March 9 to August…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Sarira Sahu , Marco Vladimir Lemus Yáñez , Luis Salvador Miranda , Alberto Rosales de León , Virendra Gupta

Violent Hard X-ray Variability of Mrk 421 Observed by NuSTAR in 2013 April

The well studied blazar Markarian 421 (Mrk 421, $z$=0.031) was the subject of an intensive multi-wavelength campaign when it flared in 2013 April. The recorded X-ray and very high energy (VHE, E$>$100 GeV) $\gamma$-ray fluxes are the…

High Energy Astrophysical Phenomena · Physics 2015-10-07 Vaidehi S. Paliya , Markus Bottcher , Chris Diltz , C. S. Stalin , S. Sahayanathan , C. D. Ravikumar

Study of the variable broadband emission of Markarian 501 during the most extreme Swift X-ray activity

Mrk501 is a very high-energy (VHE) gamma-ray blazar located at z=0.034. During a period of two weeks in July 2014, the highest X-ray activity of Mrk501 was observed in ~14 years of operation of the Neil Gehrels Swift Gamma-ray Burst…

High Energy Astrophysical Phenomena · Physics 2021-03-17 MAGIC Collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Babić , B. Banerjee , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , E. Bernardini , A. Berti , J. Besenrieder , W. Bhattacharyya , C. Bigongiari , O. Blanch , G. Bonnoli , G. Busetto , R. Carosi , G. Ceribella , S. Cikota , S. M. Colak , P. 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 Espiñera , A. Domínguez , D. Dominis Prester , M. Doro , V. Fallah Ramazani , A. Fattorini , A. Fernández-Barral , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , D. Galindo , S. Gallozzi , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , P. Giammaria , N. Godinović , D. Guberman , D. Hadasch , A. Hahn , T. Hassan , J. Herrera , J. Hoang , D. Hrupec , S. Inoue , K. Ishio , Y. Iwamura , H. Kubo , J. Kushida , D. Kuveždić , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , M. López , A. López-Oramas , B. Machado de Oliveira Fraga , C. Maggio , P. Majumdar , M. Makariev , M. Mallamaci , G. Maneva , M. Manganaro , L. Maraschi , M. Mariotti , M. Martínez , S. Masuda , D. Mazin , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , V. Moreno , E. Moretti , P. Munar-Adrove r , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , S. Paiano , J. Palacio , D. Paneque , R. Paoletti , J. M. Paredes , G. Pedaletti , P. Peñil , M. Peresano , M. Persic , P. G. Prada Moroni , E. Prandini , I. Puljak , J. R. Garcia , M. Ribó , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , K. Satalecka , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , M. Strzys , T. Surić , F. Tavecchio , P. Temnikov , T. Terzić , M. Teshima , N. Torres-Albá , S. Tsujimoto , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , I. Vovk , M. Will , D. Zarić , FACT Collaboration , : , A. Arbet-Engels , D. Baack , M. Balbo , A. Biland , M. Blank , T. Bretz , K. Bruegge , M. Bulinski , J. Buss , M. Doerr , D. Dorner , S. Einecke , D. Elsaesser , D. Hildebrand , L. Linhoff , K. Mannheim , S. Mueller , D. Neise , A. Neronov , M. Noethe , A. Paravac , W. Rhode , B. Schleicher , F. Schulz , K. Sedlaczek , A. Shukla , V. Sliusar , E. von Willert , R. Walter , C. Wendel , A. Tramacere , A. Lien , M. Perri , F. Verrecchia , M. Armas Padilla , C. Leto , A. Lähteenmäki , M. Tornikoski , J. Tammi

Multiwavelength Observations of Mrk 501 in 2008

The well-studied VHE (E >100 GeV) blazar Mrk 501 was observed between March and May 2008 as part of an extensive multiwavelength observation campaign including radio, optical, X-ray and VHE gamma-ray instruments. Mrk 501 was in a low state…

High Energy Astrophysical Phenomena · Physics 2009-07-08 D. Kranich , D. Paneque , A. Cesarini , A. Falcone , M. Giroletti , E. Hoversten , T. Hovatta , Y. Y. Kovalev , A. Lahteenmaki , E. Nieppola , C. Pagani , A. Pichel , K. Satalecka , J. Scargle , D. Steele , F. Tavecchio , D. Tescaro , M. Tornikoski , M. Villata

Multiwavelength study of VHE emission from Markarian 501 using TACTIC observations during April-May, 2012

We have observed Markarian 501 in Very High Energy (VHE) gamma-ray wavelength band for 70.6 hours from 15 April to 30 May, 2012 using TACTIC telescope. Detailed analysis of $\sim$66.3 hours of clean data revealed the presence of a TeV…

Instrumentation and Methods for Astrophysics · Physics 2017-01-25 P Chandra , K K Singh , R C Rannot , K K Yadav , H Bhatt , A K Tickoo , B Ghosal , M Kothari , K K Gaur , A Goyal , H C Goyal , N Kumar , P Marandi , N Chouhan , S Sahayanathan , K Chanchalani , N K Agarwal , V K Dhar , S R Kaul , M K Koul , R Koul , K Venugopal , C K Bhat , C Borwankar , J Bhagwan , A C Gupta

A model for delayed emission in a very-high energy gamma-ray flare in Markarian 501

Recently, the MAGIC collaboration reported evidence for a delay in the arrival times of photons of different energies during a gamma-ray flare from the blazar Markarian 501 on 2005 July 9. We apply a homogeneous synchrotron self-Compton…

Astrophysics · Physics 2009-11-05 W. Bednarek , R. M. Wagner

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

Very high energy gamma rays from Markarian 501

During remarkable flaring activity in 1997 Markarian 501 was the brightest source in the sky at TeV energies, outshining the Crab Nebula by a factor of up to 10. Periods of flaring activity each lasting a few days were observed…

Astrophysics · Physics 2007-05-23 R. J. Protheroe , C. L. Bhat , P. Fleury , E. Lorenz , M. Teshima , T. C. Weekes

Long-term spectra of the blazars Mrk 421 and Mrk 501 at TeV energies seen by HAWC

The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory surveys the very high energy sky in the 300 GeV to $>100$ TeV energy range. HAWC has detected two blazars above $11\sigma$, Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501).…

High Energy Astrophysical Phenomena · Physics 2022-04-27 A. Albert , R. Alfaro , C. Alvarez , J. R. Angeles Camacho , J. C. Arteaga-Velázquez , K. P. Arunbabu , D. Avila Rojas , H. A. Ayala Solares , V. Baghmanyan , Belmont-Moreno , K. S. Caballero-Mora , T. Capistrán , A. Carramiñana , S. Casanova , U. Cotti , J. Cotzomi , S. Coutiño de León , E. De la Fuente , R. Diaz Hernandez , M. A. DuVernois , M. Durocher , J. C. Díaz-Vélez , K. Engel , C. Espinoza , K. L. Fan , M. Fernández Alonso , N. Fraija , D. Garcia , J. A. García-González , F. Garfias , M. M. González , J. A. Goodman , J. P. Harding , B. Hona , D. Huang , F. Hueyotl-Zahuantitla , P. Hüntemeyer , A. Iriarte , V. Joshi , A. Lara , W. H. Lee , J. Lee , H. León Vargas , A. L. Longinotti , G. Luis-Raya , K. Malone , O. Martinez , J. Martínez-Castro , J. A. Matthews , P. Miranda-Romagnoli , E. Moreno , M. Mostafá , A. Nayerhoda , L. Nellen , M. Newbold , R. Noriega-Papaqui , A. Peisker , Y. Pérez Araujo , E. G. Pérez-Pérez , C. D. Rho , D. Rosa-González , H. Salazar , F. Salesa Greus , A. Sandoval , M. Schneider , J. Serna-Franco , A. J. Smith , R. W. Springer , K. Tollefson , I. Torres , R. Torres-Escobedo , F. Ureña-Mena , L. Villaseñor , X. Wang , T. Weisgarber , E. Willox , H. Zhou , C. de León

Spectral analysis of Markarian 421 and Markarian 501 with HAWC

The Hight Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory monitors the gamma-ray sky in the energy range from 100 GeV to 100 TeV and has detected two very high energy (VHE) blazars: Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501)…

High Energy Astrophysical Phenomena · Physics 2019-08-13 S. Coutiño de León , A. Carramiñana , D. Rosa-González

Rapid Variability of Mrk 421 During Extreme Flaring as Seen Through the Eyes of XMM-Newton

By studying the variability of blazars across the electromagnetic spectrum, it is possible to resolve the underlying processes responsible for rapid flux increases, so-called flares. We report on an extremely bright X-ray flare in the…

High Energy Astrophysical Phenomena · Physics 2024-03-01 A. Gokus , J. Wilms , M. Kadler , D. Dorner , M. A. Nowak , A. Kreikenbohm , K. Leiter , T. Bretz , B. Schleicher , A. G. Markowitz , K. Pottschmidt , K. Mannheim , I. Kreykenbohm , M. Langejahn , F. McBride , T. Beuchert , T. Dauser , M. Kreter , J. Abhir , D. Baack , M. Balbo , A. Biland , K. Brand , J. Buss , L. Eisenberger , D. Elsaesser , P. Guenther , D. Hildebrand , M. Linhoff , A. Paravac , W. Rhode , V. Sliusar , S. Hasan , R. Walter

The Great Markarian 421 Flare of February 2010: Multiwavelength variability and correlation studies

We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of February, 2010 when an extraordinary flare reaching a level of $\sim$27~Crab Units above 1~TeV was measured in…

High Energy Astrophysical Phenomena · Physics 2020-04-06 A. U. Abeysekara , W. Benbow , R. Bird , A. Brill , R. Brose , M. Buchovecky , J. H. Buckley , J. L. Christiansen , A. J. Chromey , M. K. Daniel , J. Dumm , A. Falcone , Q. Feng , J. P. Finley , L. Fortson , A. Furniss , N. Galante , A. Gent , G. H. Gillanders , C. Giuri , O. Gueta , T. Hassan , O. Hervet , J. Holder , G. Hughes , T. B. Humensky , C. A. Johnson , P. Kaaret , P. Kar , N. Kelley-Hoskins , M. Kertzman , D. Kieda , M. Krause , F. Krennrich , S. Kumar , M. J. Lang , P. Moriarty , R. Mukherjee , T. Nelson , D. Nieto , M. Nievas-Rosillo , S. O'Brien , R. A. Ong , A. N. Otte , N. Park , A. Petrashyk , A. Pichel , M. Pohl , R. R. Prado , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , G. T. Richards , E. Roache , A. C. Rovero , C. Rulten , I. Sadeh , M. Santander , G. H. Sembroski , K. Shahinyan , B. Stevenson , I. Sushch , J. Tyler , V. V. Vassiliev , S. P. Wakely , A. Weinstein , R. M. Wells , P. Wilcox , A. Wilhelm , D. A. Williams , B. Zitzer , 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 , 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 Espiñera , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , A. Fernández-Barral , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , D. Galindo , 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 , S. Inoue , K. Ishio , Y. Iwamura , 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 , 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 , M. Nievas Rosillo , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , M. Nöthe , 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 , K. Satalecka , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , D. Strom , M. Strzys , S. Sun , T. Surić , 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 , H. D. Aller , M. F. Aller , M. T. Carini , D. Horan , B. Jordan , Svetlana G. Jorstad , O. M. Kurtanidze , S. O. Kurtanidze , A. Lähteenmäki , V. M. Larionov , E. G. Larionova , G. Madejski , Alan P. Marscher , W. Max-Moerbeck , J. Ward Moody , D. A. Morozova , M. G. Nikolashvili , C. M. Raiteri , A. C. S. Readhead , J. L. Richards , Alberto C. Sadun , T. Sakamoto , L. A. Sigua , P. S. Smith , H. Talvikki , J. Tammi , M. Tornikoski , I. S. Troitsky , M. Villata

Multiwavelength study of TeV Blazar Mrk421 during giant flare

Context: The nearby (z=0.031) TeV blazar Mrk421 was reported to be in a high state of flux activity since November, 2009. Aims: To investigate possible changes in the physical parameters of Mrk421 during its high state of activity using…

High Energy Astrophysical Phenomena · Physics 2015-06-04 A. Shukla , V. R. Chitnis , P. R. Vishwanath , B. S. Acharya , G. C. Anupama , P. Bhattacharjee , R. J. Britto , T. P. Prabhu , L. Saha , B. B. Singh

Hourly Spectral Variability of Mrk 421

Mrk 421 is the first TeV blazar found to exhibit significant spectral variability during strong flaring activity, showing hardening of the TeV spectrum in high emission states. Mrk 421 is also known to exhibit flux variability on time…

Astrophysics · Physics 2009-09-29 F. Krennrich , I. H. Bond , P. J. Boyle , S. M. Bradbury , J. H. Buckley

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

Unprecedented temporal evolution of the broad-band emission of the BL Lac Mrk 501

The TeV BL Lac object Markarian 501 has been the subject of a 4.5 month multi-instrument campaign conducted in 2009, which provided an excellent temporal and energy coverage from radio to very high energy gamma rays (>100 GeV, VHE). During…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Marlene Doert , David Paneque