Related papers: Variability Pattern and the Spectral Evolution of …

X-Ray Polarization Variability of High Spectral Peak BL Lacertaes: Cases of 1ES 1959+650 and PKS 2155-304

The high-energy-peaked BL Lacertae objects (HBLs) are the main targets of the Imaging X-ray Polarimetry Explorer (IXPE) for investigating the mechanisms of radiation and particle acceleration in jets. In this paper, we report the first IXPE…

High Energy Astrophysical Phenomena · Physics 2024-03-01 Xin-Ke Hu , Yu-Wei Yu , Jin Zhang , Tan-Zheng Wu , Ji-Shun Lian , Xiang-Gao Wang , Hai-Ming Zhang , En-Wei Liang

Study of underlying particle spectrum during huge X-ray flare of Mkn 421 in April 2013

Context: In April 2013, the nearby (z=0.031) TeV blazar, Mkn 421, showed one of the largest flares in X-rays since the past decade. Aim: To study all multiwavelength data available during MJD 56392 to 56403, with special emphasis on X-ray…

Astrophysics of Galaxies · Physics 2015-08-12 Atreyee Sinha , Amit Shukla , Ranjeev Misra , Varsha R. Chitnis , A. R. Rao , B. S. Acharya

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

Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

A flare from the TeV blazar Mrk 421, occurring in March 2010, was observed for 13 consecutive days from radio to very high energy (VHE, E > 100 GeV) gamma-rays with MAGIC, VERITAS, Whipple, FermiLAT, MAXI, RXTE, Swift, GASP-WEBT, and…

High Energy Astrophysical Phenomena · Physics 2015-06-16 The MAGIC Collaboration , J. Aleksić , S. Ansoldi , L. A. Antonelli , P. Antoranz , A. Babic , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , E. Bernardini , B. Biasuzzi , A. Biland , O. Blanch , A. Boller , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , E. Carmona , A. Carosi , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , P. Da Vela , F. Dazzi , A. De Angelis , G. De Caneva , B. De Lotto , E. de Oña Wilhelmi , C. Delgado Mendez , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher , D. Elsaesser , M. V. Fonseca , L. Font , K. Frantzen , C. Fruck , D. Galindo , R. J. García López , M. Garczarczyk , D. Garrido Terrats , M. Gaug , N. Godinović , A. González Muñoz , S. R. Gozzini , D. Hadasch , Y. Hanabata , M. Hayashida , J. Herrera , D. Hildebrand , J. Hose , D. Hrupec , G. Hughes , W. Idec , V. Kadenius , H. Kellermann , M. L. Knoetig , K. Kodani , Y. Konno , J. Krause , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , N. Lewandowska , E. Lindfors , S. Lombardi , M. López , R. López-Coto , A. López-Oramas , E. Lorenz , I. Lozano , M. Makariev , K. Mallot , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martínez , D. Mazin , U. Menzel , J. M. Miranda , R. Mirzoyan , A. Moralejo , P. Munar-Adrover , D. Nakajima , A. Niedzwiecki , K. Nilsson , K. Nishijima , K. Noda , R. Orito , A. Overkemping , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , M. Persic , P. G. Prada Moroni , E. Prandini , I. Puljak , R. Reinthal , W. Rhode , M. Ribó , J. Rico , J. Rodriguez Garcia , S. Rügamer , T. Saito , K. Saito , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , S. Sun , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , V. Stamatescu , A. Stamerra , T. Steinbring , B. Steinke , J. Storz , M. Strzys , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , J. Thaele , O. Tibolla , D. F. Torres , T. Toyama , A. Treves , M. Uellenbeck , P. Vogler , R. Zanin , The VERITAS Collaboration , : , S. Archambault , A. Archer , M. Beilicke , W. Benbow , K. Berger , R. Bird , J. Biteau , J. H. Buckley , V. Bugaev , M. Cerruti , X. Chen , L. Ciupik , E. Collins-Hughes , W. Cui , J. D. Eisch , A. Falcone , Q. Feng , J. P. Finley , P. Fortin , L. Fortson , A. Furniss , N. Galante , G. H. Gillanders , S. Griffin , G. Gyuk , N. Håkansson , J. Holder , C. A. Johnson , P. Kaaret , P. Kar , M. Kertzman , D. Kieda , M. J. Lang , S. McArthur , A. McCann , K. Meagher , J. Millis , P. Moriarty , R. A. Ong , A. N. Otte , J. S. Perkins , A. Pichel , M. Pohl , A. Popkow , H. Prokoph , E. Pueschel , K. Ragan , L. C. Reyes , P. T. Reynolds , G. T. Richards , E. Roache , A. C. Rovero , G. H. Sembroski , K. Shahinyan , D. Staszak , I. Telezhinsky , J. V. Tucci , J. Tyler , A. Varlotta , S. P. Wakely , R. Welsing , A. Wilhelm , D. A. Williams , External Collaborators , : , S. Buson , J. Finke , M. Villata , C. Raiteri , H. D. Aller , M. F. Aller , A. Cesarini , W. P. Chen , M. A. Gurwell , S. G. Jorstad , G. N. Kimeridze , E. Koptelova , O. M. Kurtanidze , S. O. Kurtanidze , A. Lähteenmäki , V. M. Larionov , E. G. Larionova , H. C. Lin , B. McBreen , J. W. Moody , D. A. Morozova , A. P. Marscher , W. Max-Moerbeck , M. G. Nikolashvili , M. Perri , A. C. S. Readhead , J. L. Richards , J. A. Ros , A. C. Sadun , T. Sakamoto , L. A. Sigua , P. S. Smith , M. Tornikoski , I. S. Troitsky , A. E. Wehrle , B. Jordan

Optical and Radio Variability of BL Lacertae

We observed the prototype blazar, BL Lacertae, extensively in optical and radio bands during an active phase in the period 2010--2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags…

High Energy Astrophysical Phenomena · Physics 2015-10-28 Haritma Gaur , Alok C. Gupta , R. Bachev , A. Strigachev , E. Semkov , Paul J. Wiita , A. E. Volvach , Minfeng Gu , A. Agarwal , I. Agudo , M. F. Aller , H. D. Aller , O. M. Kurtanidze , S. O. Kurtanidze , A. Lahteenmaki , S. Peneva , M. G. Nikolashvili , L. A. Sigua , M. Tornikoski , L. N. Volvach

The Complex 0.1-100 keV X-Ray Spectrum of PKS2155-304

A long ($>100,000$ seconds) observation of the bright BL Lac object PKS 2155-304 has been carried out with the Narrow Field Instruments of the BeppoSAX satellite as part of the Science Verification Phase. The source was detected between 0.1…

Astrophysics · Physics 2007-05-23 P. Giommi et al

Multi-band optical variability of the Blazar S5 0716+714 in outburst state during 2014-2015

We analyzed the multi-band optical behaviour of the BL Lacertae object, S5 0716+714, during its outburst state from 2014 November - 2015 March. We took data on 23 nights at three observatories, one in India and two in Bulgaria, making…

High Energy Astrophysical Phenomena · Physics 2017-12-20 Aditi Agarwal , Alok C. Gupta , R. Bachev , A. Strigachev , E. Semkov , Paul J. Wiita , J. H. Fan , U. S. Pandey , S. Boeva , B. Spassov

Multi-Wavelength Variability of the Synchrotron Self-Compton Model for Blazar Emission

Motivated by recent reports of strongly correlated radio and X-ray variability in 3C279 (Grandi, etal 1995), we have computed the relative amplitudes of variations in the synchrotron flux at $\nu$ and the self-Compton X-ray flux at 1 keV…

Astrophysics · Physics 2009-10-28 Mark W. Sincell

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

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

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

Evolution of the synchrotron and inverse Compton emissions of the low energy peaked BL Lac object S5 0716+714

This paper presents a detailed analysis of the temporal and spectral variability of the low-energy peaked BL Lac object S5 0716+714 with a long (~74 ks)X-ray observation performed by XMM-Newton on 2007 September 24-25. The source…

High Energy Astrophysical Phenomena · Physics 2015-05-18 You-Hong Zhang

An Intense Gamma-Ray Flare of PKS1622-297

We report the observation by the Compton Gamma Ray Observatory of a spectacular flare of radio source PKS 1622-297. A peak flux of 17E-6 cm^-2 s^-1 (E > 100 MeV) was observed. The corresponding isotropic luminosity is 2.9E49 erg/s. We find…

Astrophysics · Physics 2009-10-28 J. R. Mattox , S. J. Wagner , M. Malkan , T. A. McGlynn , J. F. Schachter , J. E. Grove , W. N. Johnson , J. D. Kurfess

Multiwavelength Observations of Strong Flares From the TeV-Blazar 1ES 1959+650

Following the detection of strong TeV gamma-ray flares from the BL Lac object 1ES 1959+650 with the Whipple 10 m Cherenkov telescope on May 16 and 17, 2002, we performed intensive Target of Opportunity (ToO) radio, optical, X-ray and TeV…

Astrophysics · Physics 2008-11-26 H. Krawczynski , S. B. Hughes , D. Horan , F. Aharonian , M. F. Aller , H. Aller , P. Boltwood , J. Buckley , P. Coppi , G. Fossati , N. Goetting , J. Holder , D. Horns , O. M. Kurtanidze , A. P. Marscher , M. Nikolashvili , R. A. Remillard , A. Sadun , M. Schroeder

The optical polarization of the blazar PKS 2155$-$304 during an optical flare in 2010

An analysis is presented of the optical polarimetric and multicolour photometric ($BVRJ$) behaviour of the blazar PKS 2155$-$304 during an outburst in 2010. This flare develops over roughly 117 days, with a flux doubling time $\tau \sim 11$…

High Energy Astrophysical Phenomena · Physics 2020-05-20 N. W. Peceur , A. R. Taylor , R. C. Kraan-Korteweg

Modelling of the nonthermal flares in the galactic microquasar GRS 1915+105

We study the temporal and spectral evolution of the radio flares detected from the relativistic ejecta in the microquasar GRS 1915+105, and develop a model which suggests that these flares are due to synchrotron radiation of relativistic…

Astrophysics · Physics 2007-05-23 A. M. Atoyan , F. A. Aharonian

Multiple Components and Spectral Evolution of BL Lacertae as Revealed by Multiwavelength Variability and SED Modeling

BL Lac has entered an active state since 2020, with multiwavelength observations revealing intense flares. In this study, we conducted 12-night multicolor optical monitoring using an 85 cm telescope from 2020 September to 2024 June and…

High Energy Astrophysical Phenomena · Physics 2026-03-05 Hanxiao Xia , Ziming Wang , Jianghua Wu , Yue Fang , Shiyu Du

Exceptional X-ray activity in BL Lacertae

BL Lacertae is a unique blazar for which the X-ray band can cover either the synchrotron or the inverse Compton, or both parts of the broadband spectral energy distribution. In the latter case, when the spectral upturn is located in the…

High Energy Astrophysical Phenomena · Physics 2024-12-30 Alicja Wierzcholska , Stefan Wagner

Simultaneous observations of the blazar PKS2155-304 from Ultra-Violet to TeV energies

The results of the first ever contemporaneous multi-wavelength observation campaign on the BL Lac object PKS2155-304 involving Swift, NuSTAR, Fermi-LAT and H.E.S.S. are reported. The use of these instruments allows us to cover a broad…

High Energy Astrophysical Phenomena · Physics 2020-07-08 H. E. S. S. , Fermi , NuSTAR collaborations

The complex variability of blazars: Time-scales and periodicity analysis in S4 0954+65

Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Transiting Exoplanet Survey Satellite (TESS) and by the Whole…

High Energy Astrophysical Phenomena · Physics 2021-05-12 C. M. Raiteri , M. Villata , V. M. Larionov , S. G. Jorstad , A. P. Marscher , Z. R. Weaver