Related papers: Hour-Scale Multiwavelength Variability in Markaria…

Long-Term X-Ray and TeV variability of Mrk 501

We present X-ray observations of the blazar Mrk501 obtained with RXTE during 1997, 1998, 1999, 2000, and 2004. The goal of this study is twofold: 1) characterize the long-term X-ray flux and spectral variability of the source with a…

Astrophysics · Physics 2009-11-11 M. Gliozzi , R. Sambruna , I. Jung , H. Krawczynski , D. Horan , F. Tavecchio

Multi-wavelength study of Mrk 421 during a TeV flare

The blazar Mrk 421 shows frequent, short flares in the TeV energy regime. Due to the fast nature of such episodes, we often fail to obtain sufficient simultaneous information about flux variations in several energy bands. To overcome this…

High Energy Astrophysical Phenomena · Physics 2021-08-05 A. Gokus , A. Kreikenbohm , K. Leiter , T. Bretz , T. Dauser , D. Dorner , D. Elsaesser , F. Eppel , J. Hessdoerfer , M. Kadler , A. Kraus , M. Kreter , I. Kreykenbohm , M. Langejahn , K. Mannheim , P. Thalhammer , J. Wilms , A. Arbet-Engels , D. Baack , M. Balbo , A. Biland , J. Buss , L. Eisenberger , D. Hildebrand , R. Iotov , A. Kalenski , A. Mitchell , D. Neise , M. Noethe , A. Paravac , W. Rhode , B. Schleicher , V. Sliusar , R. Walter

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

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

Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017

We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with special focus on the multi-band flux correlations. The dataset has been collected through an…

High Energy Astrophysical Phenomena · Physics 2021-12-01 MAGIC Collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , M. Artero , K. Asano , 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 , 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 Angelis , 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 , M. Doro , 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 , 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. Peñil , C. Perennes , M. Persic , P. G. Prada Moroni , E. Prandini , C. Priyadarshi , I. Puljak , M. Ribó , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , S. Sakurai , K. Satalecka , F. G. Saturni , 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. Zarić , FACT Collaboration , : , D. Baack , M. Balbo , N. Biederbeck , A. Biland , T. Bretz , J. Buss , D. Dorner , L. Eisenberger , D. Elsaesser , D. Hildebrand , R. Iotov , K. Mannheim , D. Neise , M. Noethe , A. Paravac , W. Rhode , B. Schleicher , V. Sliusar , R. Walter , Other groups , collaborations , : , F. D'Ammando , D. Horan , A. Y. Lien , M. Baloković , G. M. Madejski , M. Perri , F. Verrecchia , C. Leto , A. Lähteenmäki , M. Tornikoski , V. Ramakrishnan , E. Järvelä , R. J. C. Vera , M. Villata , C. M. Raiteri , A. C. Gupta , A. Pandey , A. Fuentes , I. Agudo , C. Casadio , E. Semkov , S. Ibryamov , A. Marchini , R. Bachev , A. Strigachev , E. Ovcharov , V. Bozhilov , A. Valcheva , E. Zaharieva , G. Damljanovic , O. Vince , V. M. Larionov , G. A. Borman , T. S. Grishina , V. A. Hagen-Thorn , E. N. Kopatskaya , E. G. Larionova , L. V. Larionova , D. A. Morozova , A. A. Nikiforova , S. S. Savchenko , I. S. Troitskiy , Y. V. Troitskaya , A. A. Vasilyev , O. A. Merkulova , W. P. Chen , M. Samal , H. C. Lin , J. W. Moody , A. C. Sadun , S. G. Jorstad , A. P. Marscher , Z. R. Weaver , M. Feige , J. Kania , M. Kopp , L. Kunkel , D. Reinhart , A. Scherbantin , L. Schneider , C. Lorey , J. A. Acosta-Pulido , M. I. Carnerero , D. Carosati , S. O. Kurtanidze , O. M. Kurtanidze , M. G. Nikolashvili , R. G. Chanishvili , R. A. Chigladze , R. Z. Ivanidze , G. N. Kimeridze , L. A. Sigua , M. D. Joner , M. Spencer , M. Giroletti , N. Marchili , S. Righini , N. Rizzi , G. Bonnoli

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

XMM - Newton observations of Markarian 421

The BL Lac object Mrk 421 was observed on May 25, 2000 during the XMM - Newton CAL/PV phase. The high throughput of the X-ray telescopes and the spectral capabilities of the instruments allow an uninterrupted temporal and spectral study of…

Astrophysics · Physics 2009-10-31 W. Brinkmann , S. Sembay , R. G. Griffiths , G. Branduardi-Raymont , M. Gliozzi , Th. Boller , A. Tiengo , S. Molendi , S. Zane

Long-term multi-band photometric monitoring of Mrk 501

Radio-to-TeV observations of the bright nearby (z=0.034) blazar Markarian 501 (Mrk 501), performed from December 2012 to April 2018, are used to study the emission mechanisms in its relativistic jet. We examined the multi-wavelength…

High Energy Astrophysical Phenomena · Physics 2021-12-01 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 , Vitalii Sliusar , Roland Walter

Observations of Gamma-ray emission from the blazar Markarian 421 above 250 GeV with the CAT Cherenkov imaging telescope

The gamma-ray emission of the blazar Markarian 421 above 250 GeV has been observed by the CAT Cherenkov imaging telescope since December, 1996. We report here results on the source variability up to April, 1998, with emphasis on the 1998…

Astrophysics · Physics 2019-08-14 F. Piron

Extreme HBL-like behavior of Markarian 421 and its two-zone photohadronic interpretation

Markarian 421 is the nearest high-energy peaked blazar and also is the first extragalactic source to be detected in multi-TeV $\gamma$-rays. It has been observed in multiwavelength for exceptionally long period of time with dense monitoring…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Sarira Sahu , Carlos E. López Fortín , Isabel Abigail Valadez Polanco , Subhash Rajpoot

Gamma ray flares from Mrk421 in 2008 observed with the ARGO-YBJ detector

In 2008 the blazar Markarian 421 entered a very active phase and was one of the brightest sources in the sky at TeV energies, showing frequent flaring episodes. Using the data of ARGO-YBJ, a full coverage air shower detector located at…

High Energy Astrophysical Phenomena · Physics 2015-05-18 G. Aielli et al.

The Study of TeV Variability and Duty Cycle of Mrk 421 from 3 Years of Observations with the Milagro Observatory

TeV flaring activity with time scales as short as tens of minutes and an orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421). The TeV emission from Mrk 421 is believed to be produced by leptonic synchrotron…

High Energy Astrophysical Phenomena · Physics 2015-06-18 A. A. Abdo , A. U. Abeysekara , B. T. Allen , T. Aune , A. S. Barber , D. Berley , J. Braun , C. Chen , G. E. Christopher , R. S. Delay , T. DeYoung , B. L. Dingus , R. W. Ellsworth , N. Fraija , M. M. González , J. A. Goodman , E. Hays , C. M. Hoffman , P. H. Hüntemeyer , A. Imran , B. E. Kolterman , J. T. Linnemann , A. Marinelli , J. E. McEnery , T. Morgan , A. I. Mincer , P. Nemethy , B. Patricelli , J. Pretz , J. M. Ryan , P. M. Saz Parkinson , M. Schneider , A. Shoup , G. Sinnis , A. J. Smith , V. Vasileiou , G. P. Walker , D. A. Williams , G. B. Yodh

We present exactly simultaneous X-ray and TeV monitoring with {\it RXTE} and HEGRA of the TeV blazar Mrk 501 during 15 days in 1998 June. After an initial period of very low flux at both wavelengths, the source underwent a remarkable flare…

Astrophysics · Physics 2009-10-31 Rita M. Sambruna

An active state of the BL Lac Object Markarian 421 detected by INTEGRAL in April 2013

Multiwavelength variability of blazars offers indirect insight into their powerful engines and on the mechanisms through which energy is propagated from the centre down the jet. The BL Lac object Mkn 421 is a TeV emitter, a bright blazar at…

High Energy Astrophysical Phenomena · Physics 2014-10-22 E. Pian , M. Tuerler , M. Fiocchi , R. Boissay , A. Bazzano , L. Foschini , F. Tavecchio , V. Bianchin , G. Castignani , C. Ferrigno , C. M. Raiteri , M. Villata , V. Beckmann , F. D'Ammando , R. Hudec , G. Malaguti , L. Maraschi , T. Pursimo , P. Romano , S. Soldi , A. Stamerra , A. Treves , P. Ubertini , S. Vercellone , R. Walter

Limits to Quantum Gravity Effects from Observations of TeV Flares in Active Galaxies

We have used data from the TeV gamma-ray flare associated with the active galaxy Markarian 421 observed on 15 May 1996 to place bounds on the possible energy-dependence of the speed of light in the context of an effective quantum…

General Relativity and Quantum Cosmology · Physics 2010-11-30 S. D. Biller , A. C. Breslin , J. Buckley , M. Catanese , M. Carson , D. A. Carter-Lewis , M. F. Cawley , D. J. Fegan , J. Finley , J. A. Gaidos , A. M. Hillas , F. Krennrich , R. C. Lamb , R. Lessard , C. Masterson , J. E. McEnery , B. McKernan , P. Moriarty , J. Quinn , H. J. Rose , F. Samuelson , G. Sembroski , P. Skelton , T. C. Weekes

A search for spectral hysteresis and energy-dependent time lags from X-ray and TeV gamma-ray observations of Mrk 421

Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray…

High Energy Astrophysical Phenomena · Physics 2016-12-28 A. U. Abeysekara , S. Archambault , A. Archer , W. Benbow , R. Bird , M. Buchovecky , J. H. Buckley , V. Bugaev , J. V Cardenzana , M. Cerruti , X. Chen , L. Ciupik , M. P. Connolly , W. Cui , J. D. Eisch , A. Falcone , Q. Feng , J. P. Finley , H. Fleischhack , A. Flinders , L. Fortson , A. Furniss , S. Griffin , M. Hütten , N. Håkansson , D. Hanna , O. Hervet , J. Holder , T. B. Humensky , P. Kaaret , P. Kar , M. Kertzman , D. Kieda , M. Krause , S. Kumar , M. J. Lang , G. Maier , S. McArthur , A. McCann , K. Meagher , P. Moriarty , R. Mukherjee , D. Nieto , S. O'Brien , R. A. Ong , A. N. Otte , N. Park , V. Pelassa , M. Pohl , A. Popkow , E. Pueschel , K. Ragan , P. T. Reynolds , G. T. Richards , E. Roache , I. Sadeh , M. Santander , G. H. Sembroski , K. Shahinyan , D. Staszak , I. Telezhinsky , J. V. Tucci , J. Tyler , S. P. Wakely , A. Weinstein , A. Wilhelm , D. A. Williams , M. L. Ahnen , S. Ansoldi , L. A. Antonelli , P. Antoranz , C. Arcaro , A. Babic , B. Banerjee , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , E. Bernardini , A. Berti , B. Biasuzzi , A. Biland , O. Blanch , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , R. Carosi , A. Carosi , A. Chatterjee , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , P. Cumani , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , E. de Oña Wilhelmi , F. Di Pierro , M. Doert , A. Domínguez , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher Glawion , D. Elsaesser , M. Engelkemeier , V. Fallah Ramazani , A. Fernández-Barral , D. Fidalgo , M. V. Fonseca , L. Font , C. Fruck , D. Galindo , R. J. García López , M. Garczarczyk , M. Gaug , P. Giammaria , N. Godinović , D. Gora , D. Guberman , D. Hadasch , A. Hahn , T. Hassan , M. Hayashida , J. Herrera , J. Hose , D. Hrupec , G. Hughes , W. Idec , K. Kodani , Y. Konno , H. Kubo , J. Kushida , D. Lelas , E. Lindfors , S. Lombardi , F. Longo , M. López , R. López-Coto , P. Majumdar , M. Makariev , K. Mallot , G. Maneva , M. Manganaro , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martínez , D. Mazin , U. Menzel , R. Mirzoyan , A. Moralejo , E. Moretti , D. Nakajima , V. Neustroev , A. Niedzwiecki , M. Nievas Rosillo , K. Nilsson , K. Nishijima , K. Noda , L. Nogués , M. Nöthe , S. Paiano , J. Palacio , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , G. Pedaletti , M. Peresano , L. Perri , M. Persic , J. Poutanen , P. G. Prada Moroni , E. Prandini , I. Puljak , J. R. Garcia , I. Reichardt , W. Rhode , M. Ribó , J. Rico , T. Saito , K. Satalecka , S. Schroeder , T. Schweizer , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , A. Stamerra , M. Strzys , T. Surić , L. Takalo , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , D. F. Torres , N. Torres-Albà , T. Toyama , A. Treves , G. Vanzo , M. Vazquez Acosta , I. Vovk , J. E. Ward , M. Will , M. H. Wu , R. Zanin , T. Hovatta , I. de la Calle Perez , P. S. Smith , E. Racero , M. Baloković

A brief (blazar oriented) overview on topics for multi-wavelength observations with TeV photons

Multi-wavelength observations with TeV photons are an essential diagnostic tool to study the physics of TeV sources. The complex variability of blazars, however (timescales from years down to minutes, with different patterns and SED…

Astrophysics · Physics 2009-11-10 L. Costamante

Simultaneous multiwavelength observations of the second exceptional gamma-ray flare of PKS 2155-304 in July 2006

Simultaneous HESS/CHANDRA/optical observations were performed on the BL Lac object PKS 2155-304 in the night of July 29-30 2006, when the source underwent its second major gamma-ray outburst in Summer 2006. This event took place about 44…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 HESS Collaboration , F. Aharonian

Time-Dependent Modeling of the Sub-Hour Spectral Evolution During the 2013 Outburst of Mrk 421

In April 2013, the TeV blazar Markarian~421 underwent one of its most powerful emission outbursts to date. An extensive multi-instrument campaign featuring MAGIC, VERITAS, and \textit{NuSTAR} provided comprehensive very-high-energy (VHE; $E…

High Energy Astrophysical Phenomena · Physics 2026-03-06 MAGIC Collaboration , K. Abe , S. Abe , J. Abhir , A. Abhishek , A. Aguasca-Cabot , I. Agudo , T. Aniello , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , C. Arcaro , T. T. H. Arnesen , A. Babić , C. Bakshi , U. Barres de Almeida , J. A. Barrio , L. Barrios-Jiménez , I. Batković , J. Baxter , J. Becerra González , W. Bednarek , E. Bernardini , J. Bernete , A. Berti , C. Bigongiari , A. Biland , O. Blanch , G. Bonnoli , Ž Bošnjak , E. Bronzini , I. Burelli , A. Campoy-Ordaz , A. Carosi , R. Carosi , M. Carretero-Castrillo , A. J. Castro-Tirado , D. Cerasole , G. Ceribella , Y. Chai , A. Cifuentes , J. L. Contreras , J. Cortina , S. Covino , F. D'Ammando , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , R. de Menezes , J. Delgado , C. Delgado Mendez , F. Di Pierro , R. Di Tria , L. Di Venere , A. Dinesh , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , L. Eisenberger , D. Elsaesser , J. Escudero , L. Fariña , L. Foffano , L. Font , S. Fröse , Y. Fukazawa , R. J. García López , S. García Soto , M. Garczarczyk , S. Gasparyan , J. G. Giesbrecht Paiva , N. Giglietto , F. Giordano , P. Gliwny , T. Gradetzke , R. Grau , D. Green , J. G. Green , P. Günther , A. Hahn , T. Hassan , L. Heckmann , J. Herrera Llorente , D. Hrupec , D. Israyelyan , J. Jahanvi , I. Jiménez Martínez , J. Jiménez Quiles , J. Jormanainen , S. Kankkunen , T. Kayanoki , J. Konrad , P. M. Kouch , G. Koziol , H. Kubo , J. Kushida , M. Laínez , A. Lamastra , E. Lindfors , S. Lombardi , F. Longo , M. López-Moya , A. López-Oramas , S. Loporchio , L. Lulić , E. Lyard , P. Majumdar , M. Makariev , M. Mallamaci , G. Maneva , M. Manganaro , S. Mangano , K. Mannheim , S. Marchesi , M. Mariotti , M. Martínez , P. Maruševec , S. Menchiari , J. Méndez Gallego , S. Menon , D. Miceli , J. M. Miranda , R. Mirzoyan , M. Molero González , E. Molina , H. A. Mondal , A. Moralejo , C. Nanci , A. Negro , V. Neustroev , L. Nickel , M. Nievas Rosillo , C. Nigro , L. Nikolić , S. Nozaki , A. Okumura , J. Otero-Santos , S. Paiano , D. Paneque , R. Paoletti , J. M. Paredes , M. Peresano , M. Persic , M. Pihet , G. Pirola , F. Podobnik , P. G. Prada Moroni , E. Prandini , W. Rhode , M. Ribó , J. Rico , A. Roy , N. Sahakyan , F. G. Saturni , K. Schmitz , F. Schmuckermaier , T. Schweizer , A. Sciaccaluga , G. Silvestri , A. Simongini , J. Sitarek , V. Sliusar , D. Sobczynska , A. Stamerra , J. Strišković , D. Strom , M. Strzys , Y. Suda , H. Tajima , R. Takeishi , F. Tavecchio , T. Terzić , M. Teshima , A. Tutone , S. Ubach , J. van Scherpenberg , M. Vazquez Acosta , S. Ventura , G. Verna , I. Viale , A. Vigliano , C. F. Vigorito , E. Visentin , V. Vitale , I. Vovk , R. Walter , F. Wersig , M. Will , T. Yamamoto , P. K. H. Yeung , M. Petropoulou , M. Polkas , A. Mastichiadis

Long-term optical polarization variability and multiwavelength analysis of Blazar Mrk 421

The results of 8-year R-band photopolarimetric data of blazar Mrk 421 collected from February 2008 to May 2016 are presented, along with extensive multiwavelength observations covering from radio to TeV $\gamma$-rays around the flares…

High Energy Astrophysical Phenomena · Physics 2017-09-06 Nissim Fraija , Erika Benítez , David Hiriart , Marco Sorcia , Jose Manuel López , Raul Mújica , Jose Ignacio Cabrera , Jose Antonio de Diego , Miriam Rojas-Luis , Felipe Salazar-Vázquez , Antonio Galván-Gámez