Kazan Federal University Digital Repository

Extreme HBL behavior of Markarian 501 during 2012

Show simple item record

dc.contributor.author Ahnen M.
dc.contributor.author Ansoldi S.
dc.contributor.author Antonelli L.
dc.contributor.author Arcaro C.
dc.contributor.author Babić A.
dc.contributor.author Banerjee B.
dc.contributor.author Bangale P.
dc.contributor.author Barresde Almeida U.
dc.contributor.author Barrio J.
dc.contributor.author Becerragonzález J.
dc.contributor.author Bednarek W.
dc.contributor.author Bernardini E.
dc.contributor.author Berti A.
dc.contributor.author Bhattacharyya W.
dc.contributor.author Blanch O.
dc.contributor.author Bonnoli G.
dc.contributor.author Carosi R.
dc.contributor.author Carosi A.
dc.contributor.author Chatterjee A.
dc.contributor.author Colak S.
dc.contributor.author Colin P.
dc.contributor.author Colombo E.
dc.contributor.author Contreras J.
dc.contributor.author Cortina J.
dc.contributor.author Covino S.
dc.contributor.author Cumani P.
dc.contributor.author Da Vela P.
dc.contributor.author Dazzi F.
dc.contributor.author De Angelis A.
dc.contributor.author De Lotto B.
dc.contributor.author Delfino M.
dc.contributor.author Delgado J.
dc.contributor.author Di Ierro F.
dc.contributor.author Doert M.
dc.contributor.author Domínguez A.
dc.contributor.author Dominis Prester D.
dc.contributor.author Doro M.
dc.contributor.author Eisenacher Lawion D.
dc.contributor.author Engelkemeier M.
dc.contributor.author Fallah Ramazani V.
dc.contributor.author Fernández-Barral A.
dc.contributor.author Fidalgo D.
dc.contributor.author Fonseca M.
dc.contributor.author Font L.
dc.contributor.author Fruck C.
dc.contributor.author Galindo D.
dc.contributor.author García López R.
dc.contributor.author Garczarczyk M.
dc.contributor.author Gaug M.
dc.contributor.author Giammaria P.
dc.contributor.author Godinović N.
dc.contributor.author Gora D.
dc.contributor.author Guberman D.
dc.contributor.author Hadasch D.
dc.contributor.author Hahn A.
dc.contributor.author Hassan T.
dc.contributor.author Hayashida M.
dc.contributor.author Herrera J.
dc.contributor.author Hose J.
dc.contributor.author Hrupec D.
dc.contributor.author Ishio K.
dc.contributor.author Konno Y.
dc.contributor.author Kubo H.
dc.contributor.author Kushida J.
dc.contributor.author Kuve Dić D.
dc.contributor.author Lelas D.
dc.contributor.author Lindfors E.
dc.contributor.author Lombardi S.
dc.contributor.author Longo F.
dc.contributor.author López M.
dc.contributor.author Maggio C.
dc.contributor.author Majumdar P.
dc.contributor.author Makariev M.
dc.contributor.author Maneva G.
dc.contributor.author Manganaro M.
dc.contributor.author Maraschi L.
dc.contributor.author Mariotti M.
dc.contributor.author Martínez M.
dc.contributor.author Mazin D.
dc.contributor.author Menzel U.
dc.contributor.author Minev M.
dc.contributor.author Miranda J.
dc.contributor.author Mirzoyan R.
dc.contributor.author Moralejo A.
dc.contributor.author Moreno V.
dc.contributor.author Moretti E.
dc.contributor.author Nagayoshi T.
dc.contributor.author Neustroev V.
dc.contributor.author Niedzwiecki A.
dc.contributor.author Nievas Rosillo M.
dc.contributor.author Nigro C.
dc.contributor.author Nilsson K.
dc.contributor.author Ninci D.
dc.contributor.author Nishijima K.
dc.date.accessioned 2019-01-22T20:31:42Z
dc.date.available 2019-01-22T20:31:42Z
dc.date.issued 2018
dc.identifier.issn 0004-6361
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/147570
dc.description.abstract © ESO 2018. Aims. We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify the energy-dependent variability, study the potential multiband correlations, and describe the temporal evolution of the broadband emission within leptonic theoretical scenarios. Methods. We organized a multiwavelength campaign to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC, FACT and VERITAS Cherenkov telescopes, the instruments on board the Swift and Fermi spacecraft, and the telescopes operated by the GASP-WEBT collaboration. Results. Mrk 501 showed a very high energy (VHE) gamma-ray flux above 0.2 TeV of ∼0.5 times the Crab Nebula flux (CU) for most of the campaign. The highest activity occurred on 2012 June 9, when the VHE flux was ∼3 CU, and the peak of the high-energy spectral component was found to be at ∼2 TeV. Both the X-ray and VHE gamma-ray spectral slopes were measured to be extremely hard, with spectral indices < 2 during most of the observing campaign, regardless of the X-ray and VHE flux. This study reports the hardest Mrk 501 VHE spectra measured to date. The fractional variability was found to increase with energy, with the highest variability occurring at VHE. Using the complete data set, we found correlation between the X-ray and VHE bands; however, if the June 9 flare is excluded, the correlation disappears (significance < 3σ) despite the existence of substantial variability in the X-ray and VHE bands throughout the campaign. Conclusions. The unprecedentedly hard X-ray and VHE spectra measured imply that their low- and high-energy components peaked above 5 keV and 0.5 TeV, respectively, during a large fraction of the observing campaign, and hence that Mrk 501 behaved like an extreme high-frequency-peaked blazar (EHBL) throughout the 2012 observing season. This suggests that being an EHBL may not be a permanent characteristic of a blazar, but rather a state which may change over time. The data set acquired shows that the broadband spectral energy distribution (SED) of Mrk 501, and its transient evolution, is very complex, requiring, within the framework of synchrotron self-Compton (SSC) models, various emission regions for a satisfactory description. Nevertheless the one-zone SSC scenario can successfully describe the segments of the SED where most energy is emitted, with a significant correlation between the electron energy density and the VHE gamma-ray activity, suggesting that most of the variability may be explained by the injection of high-energy electrons. The one-zone SSC scenario used reproduces the behavior seen between the measured X-ray and VHE gamma-ray fluxes, and predicts that the correlation becomes stronger with increasing energy of the X-rays.
dc.relation.ispartofseries Astronomy and Astrophysics
dc.subject Acceleration of particles
dc.subject Astroparticle physics
dc.subject BL Lacertae objects: general
dc.subject BL Lacertae objects: individual: Mrk501
dc.subject Radiation mechanisms: non-thermal
dc.title Extreme HBL behavior of Markarian 501 during 2012
dc.type Article
dc.relation.ispartofseries-volume 620
dc.collection Публикации сотрудников КФУ
dc.source.id SCOPUS00046361-2018-620-SID85058842268


Files in this item

This item appears in the following Collection(s)

  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

Show simple item record

Search DSpace


Advanced Search

Browse

My Account