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Title: Radio to gamma-ray variability study of blazar S5 0716+714

Abstract

In this paper, we present the results of a series of radio, optical, X-ray, and γ-ray observations of the BL Lac object S50716+714 carried out between April 2007 and January 2011. The multifrequency observations were obtained using several ground- and space-based facilities. The intense optical monitoring of the source reveals faster repetitive variations superimposed on a long-term variability trend on a time scale of ~350 days. Episodes of fast variability recur on time scales of ~60-70 days. The intense and simultaneous activity at optical and γ-ray frequencies favors the synchrotron self-Compton mechanism for the production of the high-energy emission. Two major low-peaking radio flares were observed during this high optical/γ-ray activity period. The radio flares are characterized by a rising and a decaying stage and agrees with the formation of a shock and its evolution. We found that the evolution of the radio flares requires a geometrical variation in addition to intrinsic variations of the source. Different estimates yield robust and self-consistent lower limits of δ ≥ 20 and equipartition magnetic field B eq ≥ 0.36 G. Causality arguments constrain the size of emission region θ ≤ 0.004 mas. We found a significant correlation between flux variations at radio frequenciesmore » with those at optical and γ-rays. Theoptical/GeV flux variations lead the radio variability by ~65 days. The longer time delays between low-peaking radio outbursts and optical flares imply that optical flares are the precursors of radio ones. An orphan X-ray flare challenges the simple, one-zone emission models, rendering them too simple. Finally, here we also describe the spectral energy distribution modeling of the source from simultaneous data taken through different activity periods.« less

Authors:
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Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
Contributing Org.:
Fermi-LAT Collaboration
OSTI Identifier:
1356594
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
Astronomy and Astrophysics
Additional Journal Information:
Journal Volume: 552; Journal ID: ISSN 0004-6361
Publisher:
EDP Sciences
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; galaxies: active; BL Lacertae objects: individual: S5 0716+714; gamma rays: galaxies; X-rays: galaxies; radio continuum: galaxies

Citation Formats

Rani, B., Krichbaum, T. P., Fuhrmann, L., Böttcher, M., Lott, B., Aller, H. D., Aller, M. F., Angelakis, E., Bach, U., Bastieri, D., Falcone, A. D., Fukazawa, Y., Gabanyi, K. E., Gupta, A. C., Gurwell, M., Itoh, R., Kawabata, K. S., Krips, M., Lähteenmäki, A. A., Liu, X., Marchili, N., Max-Moerbeck, W., Nestoras, I., Nieppola, E., Quintana-Lacaci, G., Readhead, A. C. S., Richards, J. L., Sasada, M., Sievers, A., Sokolovsky, K., Stroh, M., Tammi, J., Tornikoski, M., Uemura, M., Ungerechts, H., Urano, T., and Zensus, J. A. Radio to gamma-ray variability study of blazar S5 0716+714. United States: N. p., 2013. Web. doi:10.1051/0004-6361/201321058.
Rani, B., Krichbaum, T. P., Fuhrmann, L., Böttcher, M., Lott, B., Aller, H. D., Aller, M. F., Angelakis, E., Bach, U., Bastieri, D., Falcone, A. D., Fukazawa, Y., Gabanyi, K. E., Gupta, A. C., Gurwell, M., Itoh, R., Kawabata, K. S., Krips, M., Lähteenmäki, A. A., Liu, X., Marchili, N., Max-Moerbeck, W., Nestoras, I., Nieppola, E., Quintana-Lacaci, G., Readhead, A. C. S., Richards, J. L., Sasada, M., Sievers, A., Sokolovsky, K., Stroh, M., Tammi, J., Tornikoski, M., Uemura, M., Ungerechts, H., Urano, T., & Zensus, J. A. Radio to gamma-ray variability study of blazar S5 0716+714. United States. doi:10.1051/0004-6361/201321058.
Rani, B., Krichbaum, T. P., Fuhrmann, L., Böttcher, M., Lott, B., Aller, H. D., Aller, M. F., Angelakis, E., Bach, U., Bastieri, D., Falcone, A. D., Fukazawa, Y., Gabanyi, K. E., Gupta, A. C., Gurwell, M., Itoh, R., Kawabata, K. S., Krips, M., Lähteenmäki, A. A., Liu, X., Marchili, N., Max-Moerbeck, W., Nestoras, I., Nieppola, E., Quintana-Lacaci, G., Readhead, A. C. S., Richards, J. L., Sasada, M., Sievers, A., Sokolovsky, K., Stroh, M., Tammi, J., Tornikoski, M., Uemura, M., Ungerechts, H., Urano, T., and Zensus, J. A. Wed . "Radio to gamma-ray variability study of blazar S5 0716+714". United States. doi:10.1051/0004-6361/201321058. https://www.osti.gov/servlets/purl/1356594.
@article{osti_1356594,
title = {Radio to gamma-ray variability study of blazar S5 0716+714},
author = {Rani, B. and Krichbaum, T. P. and Fuhrmann, L. and Böttcher, M. and Lott, B. and Aller, H. D. and Aller, M. F. and Angelakis, E. and Bach, U. and Bastieri, D. and Falcone, A. D. and Fukazawa, Y. and Gabanyi, K. E. and Gupta, A. C. and Gurwell, M. and Itoh, R. and Kawabata, K. S. and Krips, M. and Lähteenmäki, A. A. and Liu, X. and Marchili, N. and Max-Moerbeck, W. and Nestoras, I. and Nieppola, E. and Quintana-Lacaci, G. and Readhead, A. C. S. and Richards, J. L. and Sasada, M. and Sievers, A. and Sokolovsky, K. and Stroh, M. and Tammi, J. and Tornikoski, M. and Uemura, M. and Ungerechts, H. and Urano, T. and Zensus, J. A.},
abstractNote = {In this paper, we present the results of a series of radio, optical, X-ray, and γ-ray observations of the BL Lac object S50716+714 carried out between April 2007 and January 2011. The multifrequency observations were obtained using several ground- and space-based facilities. The intense optical monitoring of the source reveals faster repetitive variations superimposed on a long-term variability trend on a time scale of ~350 days. Episodes of fast variability recur on time scales of ~60-70 days. The intense and simultaneous activity at optical and γ-ray frequencies favors the synchrotron self-Compton mechanism for the production of the high-energy emission. Two major low-peaking radio flares were observed during this high optical/γ-ray activity period. The radio flares are characterized by a rising and a decaying stage and agrees with the formation of a shock and its evolution. We found that the evolution of the radio flares requires a geometrical variation in addition to intrinsic variations of the source. Different estimates yield robust and self-consistent lower limits of δ ≥ 20 and equipartition magnetic field Beq ≥ 0.36 G. Causality arguments constrain the size of emission region θ ≤ 0.004 mas. We found a significant correlation between flux variations at radio frequencies with those at optical and γ-rays. Theoptical/GeV flux variations lead the radio variability by ~65 days. The longer time delays between low-peaking radio outbursts and optical flares imply that optical flares are the precursors of radio ones. An orphan X-ray flare challenges the simple, one-zone emission models, rendering them too simple. Finally, here we also describe the spectral energy distribution modeling of the source from simultaneous data taken through different activity periods.},
doi = {10.1051/0004-6361/201321058},
journal = {Astronomy and Astrophysics},
number = ,
volume = 552,
place = {United States},
year = {2013},
month = {3}
}

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