Related papers: X-ray Intra-day Variability of the TeV Blazar Mrk …

X-ray Flux and Spectral Variability of Blazar H 2356-309

We present the results of timing and spectral analysis of the blazar H 2356-309 using XMM-Newton observations. This blazar is observed during 13 June 2005-24 December 2013 in total nine observations. Five of the observations show moderate…

High Energy Astrophysical Phenomena · Physics 2020-09-07 Kiran A. Wani , Haritma Gaur

Dissecting the broadband emission from {\gamma}-ray blazar PKS 0735+178 in search of neutrinos

The origin of the diffuse flux of TeV-PeV astrophysical neutrinos is still unknown. The $\gamma$-ray blazar PKS 0735+178, located outside the 90\% localization region at 2.2 deg from the best-fit IC-211208A event, was found to be flaring…

High Energy Astrophysical Phenomena · Physics 2024-01-24 Raj Prince , Saikat Das , Nayantara Gupta , Pratik Majumdar , Bożena Czerny

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

An Explanation for 13 consecutive days activities of Mrk 421

It is surprising to find a fact for migration in the peak positions of synchrotron spectra energy distribution component during in the activity epochs of Mrk 421, accompanying with an orphan flaring at the X-ray and GeV-TeV $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Y. G. Zheng , C. Y. Yang , Shi-Ju Kang , J. M. Bai

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

Optical intra-day variability in 3C 66A: 10 years of observations

We present results based on the observations of the blazar 3C 66A from 2005 November 06 to 2016 February 14 in the BVR and I broadbands using 1.2m telescope of the Mt. Abu InfraRed Observatory (MIRO). The source was observed on 160 nights…

Astrophysics of Galaxies · Physics 2017-06-14 Navpreet Kaur , Sameer , Kiran S. Baliyan , S. Ganesh

X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. I. Temporal Analysis

Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. This is the first of two papers where we present the results of a thorough temporal and spectral analysis of all the data available to us, focusing in particular on the flare of…

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

Broadband study of BL Lac during flare of 2020: Spectral evolution and emergence of HBL component

BL Lacertae (BL Lac) is categorized as TeV blazar and considered as a possible source of astrophysical neutrinos. In 2020, the brightest X-ray flare ever detected from it. A detailed study can answer many puzzling questions related to…

High Energy Astrophysical Phenomena · Physics 2021-09-22 Raj Prince

Long term variability of the blazar PKS 2155-304

Time variability of the photon flux is a known feature of active galactic nuclei (AGN) and in particular of blazars. The high frequency peaked BL Lac (HBL) object PKS 2155-304 is one of the brightest sources in the TeV band and has been…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Jill Chevalier , Max Anton Kastendieck , Frank Rieger , Gilles Maurin , Jean-Philippe Lenain , Giovanni Lamanna

Multi-band optical variability of three TeV Blazars on Diverse Timescales

We present our optical photometric observations of three TeV blazars, PKS 1510-089, PG 1553+113 and Mrk 501 taken using two telescopes in India, one in Bulgaria, one in Greece and one in Serbia during 2012 - 2014. These observations covered…

High Energy Astrophysical Phenomena · Physics 2016-02-24 Alok C. Gupta , A. Agarwal , J. Bhagwan , A. Strigachev , R. Bachev , E. Semkov , H. Gaur , G. Damljanovic , O. Vince , Paul J. Wiita

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

Microvariability in BL Lac: Zooming into the Innermost Blazar Regions

In this work, we present the results of our multi-band microvariability study of the famous blazar BL Lac. We performed microvariablity observations of the source in the optical VRI bands for 4 nights in the year 2016. We studied the…

High Energy Astrophysical Phenomena · Physics 2017-11-27 Gopal Bhatta , James R. Webb

X-Ray Luminosity and Spectral Variability in the TEV BL Lac 1ES2344+514

The results of a series of five \sax observations of the TeV BL Lac object 1ES2344+514 are briefly presented. Large amplitude luminosity variability, associated to impressive spectral changes in the hard X-rays, have been found. The shape…

Astrophysics · Physics 2019-08-17 P. Giommi , P. Padovani , E. Perlman

X-ray Observations of TeV Blazars and Multi-Frequency Analysis

The non-thermal spectra of blazars, observed from radio to GeV/TeV gamma-rays, reveal two pronounced components, both produced by radiation by energetic particles. One peaks in the IR - to soft X-ray band, radiating via the synchrotron…

Astrophysics · Physics 2009-10-31 Tadayuki Takahashi , Greg Madejski , Hidetoshi Kubo

Suzaku Discovery of a Hard X-Ray Tail in the Persistent Spectra from the Magnetar 1E 1547.0-5408 during its 2009 Activity

The fastest-rotating magnetar 1E 1547.0-5408 was observed in broad-band X-rays with Suzaku for 33 ks on 2009 January 28-29, 7 days after the onset of its latest bursting activity. After removing burst events, the absorption-uncorrected 2-10…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Enoto Teruaki , Nakazawa Kazuhiro , Makishima Kazuo , Nakagawa E. Yujin , Sakamoto Takanori , Ohno Masanori , Takahashi Tadayuki , Terada Yukikatsu , Yamaoka Kazutaka , Murakami Toshio , Takahashi Hiromitsu

Multi-wavelength observations of the TeV Blazars Mkn~421, 1ES1959+650, and H1426+428 with the HEGRA Cherenkov telescopes and the RXTE X-ray satellite

Recent results obtained with the HEGRA system of imaging Cherenkov telescopes on the TeV emission of the Blazars Mkn~421 ($z=0.030$), 1ES1959+650 ($z=0.047$), and H1426+428 ($z=0.129$) are reported. For Mkn~421, a close connection of the…

Astrophysics · Physics 2007-05-23 D. Horns , the HEGRA collaboration

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

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.

MAGIC observations of Mkn 421 in 2008, and related optical/X-ray/TeV MWL study

The HBL-type blazar Markarian 421 is one of the brightest TeV gamma-ray sources of the Northern sky. From December 2007 until June 2008 it was intensively observed in the VHE (E>100 GeV) band by the MAGIC gamma-ray telescope. The source…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Giacomo Bonnoli , Ching-Cheng Hsu , Florian Goebel , Elina Lindfors , Pratik Majumdar , Konstancja Satalecka , Antonio Stamerra , Fabrizio Tavecchio , Robert Wagner

Estimation of the TeV gamma-ray duty cycle of Mrk 421 with Milagro

The blazar Markarian 421 (Mrk 421) is one of the brightest sources in the extragalactic X-ray/TeV sky. It is also one of the fastest varying TeV $\gamma$-ray sources, showing flaring activity on time scales as short as tens of minutes. To…

High Energy Astrophysical Phenomena · Physics 2019-08-13 B. Patricelli , M. M. González , N. Fraija , A. Marinelli