Related papers: Rapid VHE variability in blazars

TeV flaring activity of the AGN PKS 0625-354 in November 2018

Most $\gamma$-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of…

High Energy Astrophysical Phenomena · Physics 2024-01-17 H. E. S. S. Collaboration , F. Aharonian , F. Ait Benkhali , J. Aschersleben , H. Ashkar , M. Backes , A. Baktash , V. Barbosa Martins , J. Barnard , R. Batzofin , Y. Becherini , D. Berge , K. Bernlöhr , B. Bi , M. Böttcher , C. Boisson , J. Bolmont , M. de Bony de Lavergne , J. Borowska , F. Bradascio , M. Breuhaus , R. Brose , A. Brown , F. Brun , B. Bruno , T. Bulik , C. Burger-Scheidlin , T. Bylund , S. Caroff , S. Casanova , R. Cecil , J. Celic , M. Cerruti , T. Chand , S. Chandra , A. Chen , J. Chibueze , O. Chibueze , G. Cotter , J. Damascene Mbarubucyeye , I. D. Davids , J. Djuvsland , A. Dmytriiev , V. Doroshenko , K. Egberts , S. Einecke , J. -P. Ernenwein , G. Fontaine , M. Füßling , S. Funk , S. Gabici , S. Ghafourizadeh , G. Giavitto , D. Glawion , J. F. Glicenstein , J. Glombitza , P. Goswami , G. Grolleron , L. Haerer , J. A. Hinton , T. L. Holch , M. Holler , D. Horns , M. Jamrozy , F. Jankowsky , V. Joshi , I. Jung-Richardt , E. Kasai , K. Katarzyński , R. Khatoon , B. Kh'elifi , z , niak , Nu. Komin , K. Kosack , D. Kostunin , R. G. Lang , S. Le Stum , F. Leitl , A. Lemière , J. -P. Lenain , F. Leuschner , A. Luashvili , J. Mackey , R. Marx , A. Mehta , M. Meyer , A. Mitchell , R. Moderski , A. Montanari , E. Moulin , M. de Naurois , J. Niemiec , P. O'Brien , S. Ohm , L. Olivera-Nieto , E. de Ona Wilhelmi , M. Ostrowski , S. Panny , R. D. Parsons , S. Pita , D. A. Prokhorov , G. Pühlhofer , M. Punch , A. Quirrenbach , P. Reichherzer , A. Reimer , O. Reimer , H. Ren , F. Rieger , B. Rudak , V. Sahakian , H. Salzmann , D. A. Sanchez , M. Sasaki , F. Schüssler , H. M. Schutte , J. N. S. Shapopi , H. Sol , A. Specovius , S. Spencer , L. , Stawarz , R. Steenkamp , S. Steinmassl , K. Streil , I. Sushch , H. Suzuki , T. Takahashi , T. Tanaka , C. van Eldik , M. Vecchi , J. Veh , C. Venter , S. J. Wagner , A. Wierzcholska , M. Zacharias , D. Zargaryan , A. A. Zdziarski , A. Zech , S. Zouari , N. Żywucka

Long-Term Profile Variability in Active Galactic Nuclei with Double-Peaked Balmer Emission Lines

An increasing number of Active Galactic Nuclei (AGNs) exhibit broad, double-peaked Balmer emission lines,which represent some of the best evidence for the existence of relatively large-scale accretion disks in AGNs. A set of 20…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Karen T. Lewis , Michael Eracleous , Thaisa Storchi-Bergmann

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

Very High Energy Active Galactic Nuclei Synchrotron self-Compton Modeling Tour

The current very high energy (VHE; E>100GeV) experiments have tremendously increased the number of detected extragalactic sources. We present a synchrotron self-Compton modeling tour of the active galactic nuclei currently established as…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 J. -P. Lenain , M. K. Daniel , C. Boisson , P. M. Chadwick , H. Sol , M. J. Ward

Polarimetric Properties of Blazars Caught by the WEBT

Active galactic nuclei come in many varieties. A minority of them are radio-loud, and exhibit two opposite prominent plasma jets extending from the proximity of the supermassive black hole up to megaparsec distances. When one of the…

High Energy Astrophysical Phenomena · Physics 2021-06-14 Claudia M. Raiteri , Massimo Villata

Discovery of VHE gamma-rays from the radio galaxy PKS 0625-354 with H.E.S.S

Most of the extragalactic objects detected so far in the very high energy (VHE) regime are blazars, but the discovered nearby radio galaxies: M87, Cen A and NGC 1275 of type FRI seem to constitute a new class of VHE emitters. The radio…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Michal Dyrda , Alicja Wierzcholska , Olivier Hervet , Rafal Moderski , Mateusz Janiak , Michał Ostrowski , Łukasz Stawarz

Long-term multi-wavelength study of 1ES 0647+250

The BL Lac object 1ES 0647+250 is one of the few distant $\gamma$-ray emitting blazars detected at very high energies (VHE, $\gtrsim$100 GeV) during a non-flaring state. It was detected with the MAGIC telescopes during its low activity in…

High Energy Astrophysical Phenomena · Physics 2023-02-08 MAGIC Collaboration , V. A. Acciari , T. Aniello , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , C. Arcaro , M. Artero , K. Asano , D. Baack , A. Babić , A. Baquero , U. Barres de Almeida , J. A. Barrio , I. Batković , J. Becerra González , W. Bednarek , E. Bernardini , M. Bernardos , A. Berti , J. Besenrieder , W. Bhattacharyya , C. Bigongiari , A. Biland , O. Blanch , H. Bökenkamp , G. Bonnoli , Ž. Bošnjak , I. Burelli , G. Busetto , R. Carosi , M. Carretero-Castrillo , G. Ceribella , Y. Chai , A. Chilingarian , S. Cikota , 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 , A. Del Popolo , 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 , G. Emery , V. Fallah Ramazani , L. Fariña , A. Fattorini , L. Font , C. Fruck , 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 , J. G. Green , D. Green , D. Hadasch , A. Hahn , T. Hassan , L. Heckmann , J. Herrera , D. Hrupec , M. Hütten , T. Inada , R. Iotov , K. Ishio , Y. Iwamura , I. Jiménez Martínez , J. Jormanainen , D. Kerszberg , Y. Kobayashi , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , L. Linhoff , S. Lombardi , F. Longo , R. López-Coto , M. López-Moya , A. López-Oramas , S. Loporchio , A. Lorini , E. Lyard , B. Machado de Oliveira Fraga , P. Majumdar , M. Makariev , G. Maneva , M. Manganaro , S. Mangano , K. Mannheim , M. Mariotti , M. Martínez , A. Mas Aguilar , D. Mazin , S. Menchiari , S. Mender , S. Mićanović , D. Miceli , T. Miener , J. M. Miranda , R. Mirzoyan , E. Molina , H. A. Mondal , A. Moralejo , D. Morcuende , V. Moreno , T. Nakamori , C. Nanci , L. Nava , V. Neustroev , M. Nievas Rosillo , C. Nigro , K. Nilsson , K. Nishijima , T. Njoh Ekoume , K. Noda , S. Nozaki , Y. Ohtani , T. Oka , J. Otero-Santos , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , L. Pavletić , M. Persic , M. Pihet , F. Podobnik , P. G. Prada Moroni , E. Prandini , G. Principe , C. Priyadarshi , I. Puljak , W. Rhode , M. Ribó , J. Rico , C. Righi , A. Rugliancich , N. Sahakyan , T. Saito , S. Sakurai , K. Satalecka , F. G. Saturni , B. Schleicher , K. Schmidt , F. Schmuckermaier , J. L. Schubert , T. Schweizer , J. Sitarek , V. Sliusar , D. Sobczynska , A. Spolon , A. Stamerra , J. Strišković , D. Strom , M. Strzys , Y. Suda , T. Surić , M. Takahashi , R. Takeishi , 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 , I. Viale , C. F. Vigorito , V. Vitale , I. Vovk , R. Walter , M. Will , C. Wunderlich , T. Yamamoto , D. Zarić , J. A. Acosta-Pulido , F. D'Ammando , T. Hovatta , S. Kiehlmann , I. Liodakis , C. Leto , W. Max-Moerbeck , L. Pacciani , M. Perri , A. C. S. Readhead , R. A. Reeves , F. Verrecchia

Gamma-ray blazars: the view from AGILE

During the first 3 years of operation the Gamma-Ray Imaging Detector onboard the AGILE satellite detected several blazars in a high gamma-ray activity: 3C 279, 3C 454.3, PKS 1510-089, S5 0716+714, 3C 273, W Comae, Mrk 421, PKS 0537-441 and…

High Energy Astrophysical Phenomena · Physics 2019-08-15 F. D'Ammando , A. Bulgarelli , A. W. Chen , I. Donnarumma , A. Giuliani , F. Longo , L. Pacciani , G. Pucella , E. Striani , M. Tavani , S. Vercellone , V. Vittorini , S. Covino , H. A. Krimm , C. M. Raiteri , P. Romano , M. Villata

On the relative importance of hadronic emission processes along the jet axis of Active Galactic Nuclei

With the coincident detection of a gamma-ray flare and a neutrino from the blazar TXS 0506+056, Active Galactic Nuclei (AGN) have been put into focus as possible sources of the diffuse neutrino flux. We present a space and time-resolved…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Mario R. Hoerbe , Paul J. Morris , Garret Cotter , Julia Becker Tjus

The curious activity in the nucleus of NGC 4151: jet interaction causing variability?

A key characteristic of many active galactic nuclei (AGN) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ~50 per cent increase in peak flux density of the AGN in…

Astrophysics of Galaxies · Physics 2020-05-13 D. R. A. Williams , R. D. Baldi , I. M. McHardy , R. J. Beswick , F. Panessa , D. May , J. Moldón , M. K. Argo , G. Bruni , B. T. Dullo , J. H. Knapen , E. Brinks , D. M. Fenech , C. G. Mundell , T. W. B. Muxlow , M. Pahari , J. Westcott

Target of Opportunity Observations of Blazars with H.E.S.S

The very-high-energy (VHE, E>100 GeV) extragalactic sky is dominated by blazars, a class of active galactic nuclei which show rapid variability at all wavelengths. Target of Opportunity (ToO) observations triggered by flaring activity…

High Energy Astrophysical Phenomena · Physics 2017-10-24 F. Schüssler , M. Seglar-Arroyo , M. Arrieta , M. Böttcher , C. Boisson , M. Cerruti , N. Chakraborty , I. D. Davids , F. Jankowsky , J. P. Lenain , H. Prokoph , D. Sanchez , S. Wagner , M. Zacharias , A. Zech , the H. E. S. S. Collaboration

Ensemble spectral variability study of Active Galactic Nuclei from the XMM-Newton serendipitous source catalogue

The variability of the X-ray spectra of active galactic nuclei (AGN) usually includes a change of the spectral slope. This has been investigated for a small sample of local AGNs by Sobolewska and Papadakis, who found that slope variations…

Astrophysics of Galaxies · Physics 2016-03-23 Roberto Serafinelli , Fausto Vagnetti , Riccardo Middei

Target of Opportunity observations of blazars with H.E.S.S.$\ $

The very high energy (VHE, E > 100 GeV) sky is dominated by blazars, radio-loud active galactic nuclei whose relativistic jet is closely aligned with the line of sight. Blazars are characterized by rapid variability at all wavelengths and…

High Energy Astrophysical Phenomena · Physics 2017-08-09 M. Cerruti , M. Böttcher , N. Chakraborty , I. D. Davids , M. Füßling , F. Jankowsky , J. P. Lenain , M. Meyer , H. Prokoph , S. Wagner , D. Zaborov , M. Zacharias , the H. E. S. S. Collaboration

AGN Models: High-Energy Emission

Astrophysical models for the high-energy emission of blazars are reviewed. Blazars ejecting relativistic radio jets at small angles to the line-of-sight are the only type of active galactic nuclei (AGN) discovered above 100 MeV. The…

Astrophysics · Physics 2007-05-23 Karl Mannheim

Multi-TeV flaring in nearby High Energy Blazars: A photohadronic scenario

Blazars are a subclass of AGN and flaring in multi-TeV gamma-ray seems to be the major activity in high energy blazars a subgrup of blazars. Flaring is also unpredictable and switches between quiescent and active states involving different…

High Energy Astrophysical Phenomena · Physics 2019-07-03 Sarira Sahu

Detection of an intranight optical hard-lag with colour variability in blazar PKS 0735+178

Blazars are a highly variable subclass of active galactic nuclei that have been observed to vary significantly during a single night. This intranight variability remains a debated phenomenon, with various mechanisms proposed to explain the…

High Energy Astrophysical Phenomena · Physics 2024-02-02 Callum McCall , Helen E. Jermak , Iain A. Steele , Shiho Kobayashi , Johan H. Knapen , Pablo M. Sánchez-Alarcón

Proper motion of the radio jets in two blazars at redshift above 3

There is still a limited number of high-redshift ($z>3$) active galactic nuclei (AGN) whose jet kinematics have been studied with very long baseline interferometry (VLBI). Without a dedicated proper motion survey, regularly conducted…

Astrophysics of Galaxies · Physics 2024-02-16 Mate Krezinger , Sandor Frey , Krisztina Perger , Krisztina E. Gabanyi , Tao An , Yingkang Zhang , Leonid I. Gurvits , Oleg Titov , Alexey Melnikov , Zsolt Paragi

Investigating Multiwavelength Lognormality with Simulations : Case of Mrk 421

Blazars are highly variable and display complex characteristics. A key characteristic is the flux probability distribution function or flux PDF whose shape depends upon the form of the underlying physical process driving variability. The BL…

High Energy Astrophysical Phenomena · Physics 2020-01-09 Nachiketa Chakraborty

High-redshift quasars at $z \geq 3$ -- III. Parsec-scale jet properties from VLBI observations

High redshift active galactic nuclei (AGN) provide key insights into early supermassive black hole growth and cosmic evolution. This study investigates the parsec-scale properties of 86 radio-loud quasars at z $\geq$ 3 using very long…

High Energy Astrophysical Phenomena · Physics 2025-02-24 Shaoguang Guo , Tao An , Yuanqi Liu , Chuanzeng Liu , Zhijun Xu , Yulia Sotnikova , Timur Mufakharov , Ailing Wang

Twenty years of blazar monitoring with the INAF radio telescopes

The extreme variability of blazars, in both timescale and amplitude, is generally explained as the effect of a relativistic jet closely aligned to the observer's line-of-sight. Due to causality arguments, variability characteristics…

High Energy Astrophysical Phenomena · Physics 2025-10-15 N. Marchili , S. Righini , M. Giroletti , C. M. Raiteri , R. P. Giri , M. I. Carnerero , M. Villata , U. Bach , P. Cassaro , E. Liuzzo , C. S. Buemi , P. Leto , C. Trigilio , G. Umana , M. Bonato , B. Patricelli , A. Stamerra