Related papers: Unveiling the X-ray/TeV engine in Mkn 421

Complex Spectral Variability from Intensive Multi-wavelength Monitoring of Mrk421 in 1998

We conducted a multi-frequency campaign for the TeV blazar Mrk~421 in 1998 April. The campaign started from a pronounced high amplitude flare recorded by SAX and Whipple; ASCA observation started three days later. In the X-ray data, we…

Astrophysics · Physics 2009-10-31 T. Takahashi , J. Kataoka , G. Madejski , J. Mattox , C. M. Urry , S. Wagner , F. Aharonian , M. Catanese , L. Chiappetti , P. Coppi , B. Degrange , G. Fossati , H. Kubo , H. Krawczynski , F. Makino , H. Marshall , L. Maraschi , F. Piron , R. Remillard , F. Takahara , M. Tashiro , H. Terasranta , T. Weekes

VHE $\gamma$-ray/X-ray correlation studies in Mrk 421 down to the quiescent state

The blazar Mrk 421 is one of the closest, brightest and fastest varying source in the extragalactic X-ray/TeV sky. In the last years, many multi-wavelength campaigns have been carried out to study the correlation between the very high…

High Energy Astrophysical Phenomena · Physics 2015-08-27 Barbara Patricelli , Magdalena González , Nissim Fraija

First characterization of the emission behavior of Mrk421 from radio to VHE gamma rays with simultaneous X-ray polarization measurements

We perform the first broadband study of Mrk421 from radio to TeV gamma rays with simultaneous measurements of the X-ray polarization from IXPE. The data were collected within an extensive multiwavelength campaign organized between May and…

High Energy Astrophysical Phenomena · Physics 2023-12-19 S. Abe , J. Abhir , V. A. Acciari , I. Agudo , T. Aniello , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , C. Arcaro , M. Artero , K. Asano , A. Babić , A. Baquero , U. Barres de Almeida , J. A. Barrio , I. Batković , J. Baxter , J. Becerra González , W. Bednarek , E. Bernardini , J. Bernete , A. Berti , J. Besenrieder , C. Bigongiari , A. Biland , O. Blanch , G. Bonnoli , Ž. Bošnjak , I. Burelli , G. Busetto , A. Campoy-Ordaz , A. Carosi , R. Carosi , M. Carretero-Castrillo , A. J. Castro-Tirado , G. Ceribella , Y. Chai , A. Cifuentes , S. Cikota , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , F. D'Ammando , G. D'Amico , V. D'Elia , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , R. de Menezes , A. Del Popolo , J. Delgado , C. Delgado Mendez , F. Di Pierro , L. Di Venere , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , G. Emery , J. Escudero , L. Fariña , A. Fattorini , L. Foffano , L. Font , S. Fröse , S. Fukami , Y. Fukazawa , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , J. G. Giesbrecht Paiva , N. Giglietto , F. Giordano , P. Gliwny , N. Godinović , T. Gradetzke , R. Grau , D. Green , J. G. Green , P. Günther , D. Hadasch , A. Hahn , T. Hassan , L. Heckmann , J. Herrera , D. Hrupec , M. Hütten , R. Imazawa , T. Inada , K. Ishio , I. Jiménez Martínez , J. Jormanainen , D. Kerszberg , G. W. Kluge , Y. Kobayashi , P. M. Kouch , H. Kubo , J. Kushida , M. Láinez Lezáun , A. Lamastra , F. Leone , E. Lindfors , L. Linhoff , S. Lombardi , F. Longo , R. López-Coto , M. López-Moya , A. López-Oramas , S. Loporchio , A. Lorini , B. Machado de Oliveira Fraga , P. Majumdar , M. Makariev , G. Maneva , N. Mang , M. Manganaro , S. Mangano , K. Mannheim , M. Mariotti , M. Martínez , M. Martínez-Chicharro , A. Mas-Aguilar , D. Mazin , S. Menchiari , S. Mender , D. Miceli , T. Miener , J. M. Miranda , R. Mirzoyan , M. Molero González , E. Molina , H. A. Mondal , A. Moralejo , D. Morcuende , T. Nakamori , C. Nanci , L. Nava , V. Neustroev , L. Nickel , M. Nievas Rosillo , C. Nigro , L. Nikolić , K. Nilsson , K. Nishijima , T. Njoh Ekoume , K. Noda , S. Nozaki , Y. Ohtani , A. Okumura , J. Otero-Santos , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , D. Pavlović , M. Peresano , M. Persic , M. Pihet , G. Pirola , F. Podobnik , P. G. Prada Moroni , E. Prandini , G. Principe , C. Priyadarshi , W. Rhode , M. Ribó , J. Rico , C. Righi , N. Sahakyan , T. Saito , K. Satalecka , F. G. Saturni , B. Schleicher , K. Schmidt , F. Schmuckermaier , J. L. Schubert , T. Schweizer , A. Sciaccaluga , J. Sitarek , V. Sliusar , D. Sobczynska , A. Stamerra , J. Strišković , D. Strom , M. Strzys , Y. Suda , S. Suutarinen , H. Tajima , M. Takahashi , R. Takeishi , F. Tavecchio , P. Temnikov , K. Terauchi , T. Terzić , M. Teshima , L. Tosti , S. Truzzi , A. Tutone , S. Ubach , J. van Scherpenberg , M. Vazquez Acosta , S. Ventura , I. Viale , C. F. Vigorito , V. Vitale , I. Vovk , R. Walter , M. Will , C. Wunderlich , T. Yamamoto , I. Liodakis , S. G. Jorstad , L. D. Gesu , I. Donnarumma , D. E. Kim , A. P. Marscher , R. Middei , M. Perri , S. Puccetti , F. Verrecchia , C. Leto , I. De La Calle Pérez , E. Jiménez-Bailón , D. Blinov , I. G. Bourbah , S. Kiehlmann , E. Kontopodis , N. Mandarakas , R. Skalidis , A. Vervelaki , F. J. Aceituno , B. Agís-González , A. Sota , M. Sasada , Y. Fukazawa , K. S. Kawabata , M. Uemura , T. Mizuno , H. Akitaya , C. Casadio , I. Myserlis , A. Sievers , A. Lähteenmäki , I. Syrjärinne , M. Tornikoski , Q. Salomé , M. Gurwell , G. K. Keating , R. Rao

Probing Spectral Evolution and Intrinsic Variability of Mkn\,421: A Multi-Epoch AstroSat Study of X-ray Spectra

Our study presents a time-resolved X-ray spectral analysis of Mkn 421, using AstroSat observations taken during different epochs between 2016 and 2019. The variability of the source in X-rays is utilized to investigate the evolution of its…

High Energy Astrophysical Phenomena · Physics 2025-01-15 Sikandar Akbar , Zahir Shah , Ranjeev Misra , Naseer Iqbal , Javaid Tantry

Observing Mkn 421 with XMM--Newton: the EPIC--PN point of view

We present three observations (four exposures) of Mkn 421 performed by XMM--Newton in the Autumn of 2002, concentrating on the EPIC--PN camera data. The X-ray spectra were soft and steepening toward high energies. The source was highly…

Astrophysics · Physics 2009-11-10 M. Ravasio , G. Tagliaferri , G. Ghisellini , F. Tavecchio

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

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

Observation of Strong Variability in the X-Ray Emission from Markarian 421 Correlated with the May 1996 TeV Flare

We observed the BL Lac object Markarian 421 with the X-ray satellite RXTE and the Whipple Air Cerenkov Telescope during a two week correlated X-ray/gamma-ray campaign in May 1996. Two dramatic outbursts with extremely rapid and strong flux…

Astrophysics · Physics 2009-10-30 Michael Schubnell

Unravelling the complex behavior of Mrk 421 with simultaneous X-ray and VHE observations during an extreme flaring activity in April 2013

We report on a multi-band variability and correlation study of the TeV blazar Mrk 421 during an exceptional flaring activity observed from 2013 April 11 to 2013 April 19. The study uses, among others, data from GASP-WEBT, Swift, NuSTAR,…

High Energy Astrophysical Phenomena · Physics 2020-07-22 MAGIC collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , D. Baack , A. Babic , B. Banerjee , U. Barres de Almeida , J. A. Barrio , J. Becerra Gonzalez , 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 , M. Cerruti , Y. Chai , A. Chilingarian , 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 , F. Del Puppo , M. Delfino , J. Delgado , D. Depaoli , F. Di Pierro , L. Di Venere , E. Do Souto Espineira , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , G. Ferrara , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , S. Fukami , R. J. Garcia Lopez , M. Garczarczyk , S. Gasparyan , M. Gaug , N. Giglietto , F. Giordano , P. Gliwny , N. Godinovic , D. Green , D. Hadasch , A. Hahn , J. Herrera , J. Hoang , D. Hrupec , M. Hutten , T. Inada , S. Inoue , K. Ishio , Y. Iwamura , L. Jouvin , Y. Kajiwara , D. Kerszberg , Y. Kobayashi , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , M. Lopez , R. Lopez-Coto , A. Lopez-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. Martinez , D. Mazin , S. Mender , S. Micanovic , D. Miceli , T. Miener , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , D. Morcuende , V. Moreno , E. Moretti , P. Munar-Adrover , V. Neustroev , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogues , S. Nozaki , Y. Ohtani , T. Oka , J. Otero-Santos , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , L. Pavletic , P. Penil , M. Peresano , M. Persic , P. G. Prada Moroni , E. Prandini , I. Puljak , W. Rhode , M. Ribo , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , S. Sakurai , K. Satalecka , B. Schleicher , K. Schmidt , T. Schweizer , J. Sitarek , I. Snidaric , D. Sobczynska , A. Spolon , A. Stamerra , D. Strom , M. Strzys , Y. Suda , T. Suric , M. Takahashi , F. Tavecchio , P. Temnikov , T. Terzic , M. Teshima , N. Torres-Alba , L. Tosti , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , S. Ventura , V. Verguilov , C. F. Vigorito , V. Vitale , I. Vovk , M. Will , D. Zaric , Other groups , : , M. Petropoulou , J. Finke , F. D'Ammando , M. Balokovic , G. Madejski , K. Mori , Simonetta Puccetti , C. Leto , M. Perri , F. Verrecchia , M. Villata , C. M. Raiteri , I. Agudo , R. Bachev , A. Berdyugin , D. A. Blinov , R. Chanishvili , W. P. Chen , R. Chigladze , G. Damljanovic , C. Eswaraiah , T. S. Grishina , S. Ibryamov , B. Jordan , S. G. Jorstad , M. Joshi , E. N. Kopatskaya , O. M. Kurtanidze , S. O. Kurtanidze , E. G. Larionova , L. V. Larionova , V. M. Larionov , G. Latev , H. C. Lin , A. P. Marscher , A. A. Mokrushina , D. A. Morozova , M. G. Nikolashvili , E. Semkov , P. S. Smith , A. Strigachev , Yu. V. Troitskaya , I. S. Troitsky , O. Vince , J. Barnes , T. Guever , J. W. Moody , A. C. Sadun , T. Hovatta , J. L. Richards , W. Max-Moerbeck , A. C. R. Readhead , A. Lahteenmaki , M. Tornikoski , J. Tammi , V. Ramakrishnan , R. Reinthal

X-ray and gamma-ray variability of Mrk 421

We present an ordinary case in the momentum diffusion equation for the electron spectrum evolution and investigate the energy spectra and time dependent properties of flare in Mrk 421 in the frame of a time-dependent one-zone synchrotron…

High Energy Astrophysical Phenomena · Physics 2016-08-02 Y. G. Zheng , S. J. Kang , J. Li

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

Multi-band Variability Analysis of Mrk 421

We have assembled the historical variability data of Mrk 421 at radio 15 GHz, X-ray and gamma-ray bands, spanning about 6.3, 10.3 and 7.5 yr, respective- ly. We analyzed the variability by using three methods. The results indicated that…

High Energy Astrophysical Phenomena · Physics 2016-06-22 H. Z. Li , Y. G. Jiang , D. F. Guo , X. Chen , T. F. Yi

Observations of Mkn 421 in 2004 with H.E.S.S. at large zenith angles

Mkn 421 was observed during a high flux state for nine nights in April and May 2004 with the fully operational High Energy Stereoscopic System (H.E.S.S.) in Namibia. The observations were carried out at zenith angles of…

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

X-ray variability of AGN and correlations with spectral properties

Rapid flux changes in the X-ray emission from active galactic nuclei are commonly observed. The power-density spectra show a pseudo power-law form with a turnover at low frequencies and a high frequency break, similar to galactic black-hole…

Astrophysics · Physics 2009-10-31 K. Nandra

Signatures of synchrotron emission and of electron acceleration in the X-ray spectra of Mrk 421

BL Lac objects undergo strong flux variations involving considerable changes in their spectral shapes. We specifically investigate the X-ray spectral evolution of Mrk 421 over a time span of about nine years. We aim at statistically…

Astrophysics · Physics 2009-11-13 A. Tramacere , F. Massaro , A. Cavaliere

The 0.1-100 keV spectral shape and variability of Mkn421 in high state

The results of a BeppoSAX TOO observation of the BL Lac object Mkn421 during a high intensity state are reported and compared with monitoring X-ray data collected with the BeppoSAX Wide Field Cameras (WFC) and the RXTE All Sky Monitor(ASM).…

Astrophysics · Physics 2009-10-31 A. Malizia , M. Capalbi , F. Fiore , P. Giommi , G. Gandolfi , A. Tesseri , L. A. Antonelli , R. C. Butler , G. Celidonio , A. Coletta , L. Di Ciolo , J. M. Muller , L. Piro , S. Rebecchi , D. Ricci , R. Ricci , M. Smith , V. Torroni

X-ray Intra-day Variability of the TeV Blazar Mrk 421 with Suzaku

We present X-ray flux and spectral analyses of the three pointed Suzaku observations of the TeV high synchrotron peak blazar Mrk 421 taken throughout its complete operational duration. The observation taken on 5 May 2008 is, at 364.6…

High Energy Astrophysical Phenomena · Physics 2019-11-06 Zhongli Zhang , Alok C. Gupta , Haritma Gaur , Paul J. Wiita , Tao An , Minfeng Gu , Dan Hu , Haiguang Xu

Patterns of energy-dependent variability from Comptonization

We study fractional variability as a function of energy from black-hole X-ray binaries on timescales from milliseconds to hundreds of seconds. We build a theoretical model of energy-dependent variability in which the X-ray energy spectrum…

Astrophysics · Physics 2009-11-11 Marek Gierlinski , Andrzej A. Zdziarski

Cross-spectral analysis of the X-ray variability of Mrk 421

Using the cross-spectral method, we confirm the existence of the X-ray hard lags discovered with cross-correlation function technique during a large flare of Mrk 421 observed with BeppoSAX . For the 0.1--2 versus 2--10keV light curves, both…

Astrophysics · Physics 2009-11-07 Y. H. Zhang

Rapid Variability of Gamma-Ray Blazars: A Model for MKN 421

The extremely rapid burst of TeV photons from Mkn 421 (15 May 1996) can be reconciled with the standard properties of a relativistic gamma-ray emitting jet (bulk Lorentz factor $\approx$ 10; size $\10^{17}$ cm) if one assumes that the…

Astrophysics · Physics 2015-06-24 M. Salvati , M. Spada , F. Pacini