Gamma-Ray and Optical Oscillations in PKS 0537-441
Abstract
We have considered the Fermi γ-ray light curve of the blazar PKS 0537-441 during a high state extending from 2008 August 10 to 2011 August 27. The periodogram exhibits a peak at T ∼ 280 days, with a significance of ∼99.7%. A peak of similar relevance at \frac{1}{2}T is found in the optical light curves. Considering the entire duration of the Fermi light curve 2008-2015, no significant peak is revealed, while the optical one remains meaningful. Comparing with recent observations of PKS 2155-304 and PG 1553+113 it seems that month-year oscillations can characterize some blazars. Month-scale oscillations can also show up only during phases of enhanced or bursting emission, such as in the case of PKS 0537-441.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2016
- DOI:
- 10.3847/0004-637X/820/1/20
- arXiv:
- arXiv:1512.08801
- Bibcode:
- 2016ApJ...820...20S
- Keywords:
-
- BL Lacertae objects: general;
- BL Lacertae objects: individual: PKS 0537–441;
- galaxies: jets;
- gamma rays: galaxies;
- gamma rays: general;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 6 figures, accepted for publication in The Astrophysical Journal