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Multifrequency studies of the peculiar quasar 4C+21.35 during the 2010 flaring activity



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Antoranz Canales, Pedro and Barrio Uña, Juan Abel and Contreras González, José Luis and Fonseca González, Mª Victoria and López Moya, Marcos and Miranda Pantoja, José Miguel and Satalecka, Konstanzja and Scapin, Valeria (2014) Multifrequency studies of the peculiar quasar 4C+21.35 during the 2010 flaring activity. Astrophysical journal, 786 (2). ISSN 0004-637X


Official URL: http://dx.doi.org/10.1088/0004-637X/786/2/157



The discovery of rapidly variable Very High Energy ( VHE; E > 100 GeV). - ray emission from 4C + 21.35 ( PKS 1222+ 216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope ( LAT) in high energy ( HE; E > 100 MeV). - rays, poses intriguing questions on the location of the. - ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C + 21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a gamma- ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two gamma- ray peaks, while no clear connection was observed between the X-ray and gamma- ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing gamma- ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime ( 230 GHz). We model the spectral energy distributions ( SEDs) of 4C + 21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of < six gravitational radii, as one would expect from a prograde-rotating Kerr black hole.

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© The American Astronomical Society. The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariatà l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A.Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’ Études Spatiales in France. MAGIC Collaboration would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged. This work was also supported by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 127740 of the Academy of Finland, by the DFG Cluster of Excellence “Origin and Structure of the Universe,” by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0. We thank the Swift team for making these observations possible, the duty scientists, and science planners. This research has made use of data from the MOJAVE database that is maintained by the MOJAVE team (Lister et al. 2009, AJ, 137, 3718). The MOJAVE project is supported under NASA-Fermi grant 11-Fermi11-0019. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work made use of the Swinburne University of Technology software correlator (Deller et al. 2011, PASP, 123, 275), developed as part of the Australian Major National Research Facilities Programme and operated under license. The OVRO 40-m monitoring program is supported in part by NASA grants NNX08AW31G and NNX11A043G, and NSF grants AST-0808050 and AST-1109911. This paper is partly based on observations with the 100m telescope of the MPIfR (Max-Planck-Institut für Radioastronomie) at Effelsberg and the Medicina telescope operated by INAF–Istituto di Radioastronomia. We acknowledge A. Orlati, S. Righini, and the Enhanced Single-dish Control System (ESCS) Development Team. We acknowledge financial contribution from agreement ASI-INAF I/009/10/0. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Data from the Steward Observatory spectropolarimetric monitoring project were used. This program is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, and NNX12AO93G. The St. Petersburg University team acknowledges support from Russian RFBR foundation, grants 12-02-00452 and 12-02-31193. The Abastumani team acknowledges financial support of the project FR/638/6-320/12 by the Shota Rustaveli National Science Foundation under contract 31/77. The Metsähovi team acknowledges support from the Academy of Finland to our observing projects (numbers 212656, 210338, 121148, and others). E.R. was partially supported by the Spanish MINECO projectsAYA2009-13036-C02-02 and AYA2012-38491-C02-01 and by the Generalitat Valenciana project PROMETEO/2009/104, as well as by the COST MP0905 action “Black Holes in a Violent Universe.” Y.Y.K. was partly supported by the Russian Foundation for Basic Research (project 13-02-12103) and the Dynasty Foundation. We thank the anonymous referee for useful comments and suggestions. J.F. would like to thank J. Steiner for useful discussions regarding the black hole spin of 4C +21.35. F.D. thanks P. Smith for useful discussions about the polarimetric observations of 4C +21.35.

Uncontrolled Keywords:Ray Bright Blazars, Black-Hole Mass, Extragalactic Background Light, Spectrum Radio Wuasars, Large-Area Telescope, BL Lacertae Objects, Gamma-Ray, Galactic Nuclei, X-Ray, Emission-Line.
Subjects:Sciences > Physics > Electricity
Sciences > Physics > Electronics
Sciences > Physics > Nuclear physics
ID Code:26655
Deposited On:11 Sep 2014 07:54
Last Modified:10 Dec 2018 14:57

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