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RoboPol: first season rotations of optical polarization plane in blazars

Blinov, D. and Pavlidou, V. and Papadakis, I. and Kiehlmann, S. and Panopoulou, G. and Liodakis, I. and King, O. G. and Angelakis, E. and Baloković, M. and Das, H. and Feiler, R. and Fuhrmann, L. and Hovatta, T. and Khodade, P. and Kus, A. and Kylafis, N. and Mahabal, A. and Myserlis, I. and Modi, D. and Pazderska, B. and Pazderski, E. and Papamastorakis, I. and Pearson, T. J. and Rajarshi, C. and Ramaprakash, A. and Reig, P. and Readhead, A. C. S. and Tassis, K. and Zensus, J. A. (2015) RoboPol: first season rotations of optical polarization plane in blazars. Monthly Notices of the Royal Astronomical Society, 453 (2). pp. 1669-1683. ISSN 0035-8711.

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We present first results on polarization swings in optical emission of blazars obtained by RoboPol, a monitoring programme of an unbiased sample of gamma-ray bright blazars specially designed for effective detection of such events. A possible connection of polarization swing events with periods of high activity in gamma-rays is investigated using the data set obtained during the first season of operation. It was found that the brightest gamma-ray flares tend to be located closer in time to rotation events, which may be an indication of two separate mechanisms responsible for the rotations. Blazars with detected rotations during non-rotating periods have significantly larger amplitude and faster variations of polarization angle than blazars without rotations. Our simulations show that the full set of observed rotations is not a likely outcome (probability ≤1.5 × 10^(−2)) of a random walk of the polarization vector simulated by a multicell model. Furthermore, it is highly unlikely (∼5 × 10^(−5)) that none of our rotations is physically connected with an increase in gamma-ray activity.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Kiehlmann, S.0000-0001-6314-9177
Liodakis, I.0000-0001-9200-4006
Angelakis, E.0000-0001-7327-5441
Hovatta, T.0000-0002-2024-8199
Mahabal, A.0000-0003-2242-0244
Pearson, T. J.0000-0001-5213-6231
Readhead, A. C. S.0000-0001-9152-961X
Tassis, K.0000-0002-8831-2038
Additional Information:© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2015 July 27. Received 2015 July 27; in original form 2015 May 28. First published online August 26, 2015. The RoboPol project is a collaboration between Caltech in the USA, MPIfR in Germany, Toruń Centre for Astronomy in Poland, the University of Crete/FORTH in Greece and IUCAA in India. The University of Crete group acknowledges support by the ‘RoboPol’ project, which is implemented under the ‘Aristeia’ Action of the ‘Operational Programme Education and Lifelong Learning’ and is co-funded by the European Social Fund (ESF) and Greek National Resources, and by the European Commission Seventh Framework Programme (FP7) through grants PCIG10-GA-2011-304001 ‘JetPop’ and PIRSES-GA-2012-31578 ‘EuroCal’. This research was supported in part by NASA grant NNX11A043G and NSF grant AST-1109911, and by the Polish National Science Centre, grant number 2011/01/B/ST9/04618. KT acknowledges support by the FP7 through the Marie Curie Career Integration Grant PCIG-GA-2011-293531 ‘SFOnset’. MB acknowledges support from NASA Headquarters under the NASA Earth and Space Science Fellowship Program, grant NNX14AQ07H. TH was supported in part by the Academy of Finland project number 267324. IM and SK are supported for this research through a stipend from the International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Universities of Bonn and Cologne. 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 Commissariat à 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, Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France.
Funding AgencyGrant Number
European Social FundUNSPECIFIED
Greek National Strategic Reference Framework (NSRF)UNSPECIFIED
Marie Curie FellowshipPCIG10-GA-2011-304001 'JetPop’
European Research Council (ERC)PIRSES-GA-2012-31578
National Science Centre (Poland)2011/01/B/ST9/04618
Marie Curie FellowshipPCIG-GA-2011-293531 ‘SFOnset’
NASA Earth and Space Science FellowshipNNX14AQ07H
Academy of Finland267324
International Max Planck Research School (IMPRS) for Astronomy and AstrophysicsUNSPECIFIED
Department of Energy (DOE)UNSPECIFIED
Commissariat à l’Energie Atomique (CEA)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)UNSPECIFIED
Agenzia Spaziale Italiana (ASI)UNSPECIFIED
Istituto Nazionale di Fisica Nucleare (INFN)UNSPECIFIED
Ministry of Education, Culture, Sports, Science and Technology (MEXT)UNSPECIFIED
High Energy Accelerator Research Organization (KEK)UNSPECIFIED
Japan Aerospace Exploration Agency (JAXA)UNSPECIFIED
Knut and Alice Wallenberg FoundationUNSPECIFIED
Swedish Research CouncilUNSPECIFIED
Swedish National Space Board (SNSB)UNSPECIFIED
Istituto Nazionale di Astrofisica (INAF)UNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Subject Keywords:polarization – galaxies: active – galaxies: jets – galaxies: nuclei
Issue or Number:2
Record Number:CaltechAUTHORS:20151119-131813515
Persistent URL:
Official Citation:D. Blinov, V. Pavlidou, I. Papadakis, S. Kiehlmann, G. Panopoulou, I. Liodakis, O. G. King, E. Angelakis, M. Baloković, H. Das, R. Feiler, L. Fuhrmann, T. Hovatta, P. Khodade, A. Kus, N. Kylafis, A. Mahabal, I. Myserlis, D. Modi, B. Pazderska, E. Pazderski, I. Papamastorakis, T. J. Pearson, C. Rajarshi, A. Ramaprakash, P. Reig, A. C. S. Readhead, K. Tassis, and J. A. Zensus RoboPol: first season rotations of optical polarization plane in blazars MNRAS (October 21, 2015) Vol. 453 1669-1683 doi:10.1093/mnras/stv1723 First published online August 26, 2015
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:62245
Deposited By: George Porter
Deposited On:19 Nov 2015 21:50
Last Modified:20 May 2020 21:28

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