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Title: QUASI-PERIODICITIES AT YEAR-LIKE TIMESCALES IN BLAZARS

We searched for quasi-periodicities on year-like timescales in the light curves of six blazars in the optical—near-infrared bands and we made a comparison with the high energy emission. We obtained optical/NIR light curves from Rapid Eye Mounting photometry plus archival Small and Moderate Aperture Research Telescope System data and we accessed the Fermi light curves for the γ-ray data. The periodograms often show strong peaks in the optical and γ-ray bands, which in some cases may be inter-related. The significance of the revealed peaks is then discussed, taking into account that the noise is frequency dependent. Quasi-periodicities on a year-like timescale appear to occur often in blazars. No straightforward model describing these possible periodicities is yet available, but some plausible interpretations for the physical mechanisms causing periodic variabilities of these sources are examined.
Authors:
;  [1] ;  [2] ;  [3]
  1. Università degli Studi dell’Insubria, Dipartimento di Scienza ed Alta Tecnologia, Via Valleggio 11, I-22100 Como (Italy)
  2. INAF—Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, I-23807 Merate (Italy)
  3. Università degli Studi di Milano Bicocca, Dipartimento di Fisica G. Occhialini, Piazza della Scienza 3, I-20126 Milano (Italy)
Publication Date:
OSTI Identifier:
22520006
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 151; Journal Issue: 3; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; BL LACERTAE OBJECTS; COMPARATIVE EVALUATIONS; DIAGRAMS; EMISSION SPECTROSCOPY; FREQUENCY DEPENDENCE; GALAXIES; GAMMA SPECTRA; PERIODICITY; PHOTOMETRY; QUASARS; STAR MODELS; TELESCOPES; VISIBLE RADIATION