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Gamma-ray and optical oscillations of 0716+714, MRK421, and BL Lacertae.

Authors :
Sandrinelli, A.
Covino, S.
Treves, A.
Lindfors, E.
Raiteri, C. M.
Nilsson, K.
Takalo, L. O.
Reinthal, R.
Berdyugin, A.
Ramazani, V. Fallah
Kadenius, V.
Tuominen, T.
Kehusmaa, P.
Bachev, R.
Strigachev, A.
Source :
Astronomy & Astrophysics / Astronomie et Astrophysique; Apr2017, Vol. 600, p1-7, 7p
Publication Year :
2017

Abstract

We examine the 2008-2016 γ-ray and optical light curves of three bright BL Lac objects, 0716+714, MRK421, BL Lac, which exhibit large structured variability. We searched for periodicities by using a fully Bayesian approach. For two out of three sources investigated, no significant periodic variability was found. In the case of BL Lac, we detected a periodicity of ~680 days. Although the signal related to this is modest, the coincidence of the periods in both gamma and optical bands is indicative of a physical relevance. Taking into consideration previous literature results, possibly related γ-ray and optical periodicities of about one year time scale are proposed in four bright γ-ray blazars out of the ten examined in detail. Compared with results from periodicity search of optical archives of quasars, the presence of quasi-periodicities in blazars may be more frequent by a large factor. This suggests the intriguing possibility that the basic conditions for their observability are related to the relativistic jet in the observer direction, but the overall picture remains uncertain. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00046361
Volume :
600
Database :
Complementary Index
Journal :
Astronomy & Astrophysics / Astronomie et Astrophysique
Publication Type :
Academic Journal
Accession number :
123029512
Full Text :
https://doi.org/10.1051/0004-6361/201630288