Revisiting Quasi-periodic Modulation in γ-Ray Blazar PKS 2155-304 with Fermi Pass 8 Data
Abstract
We examine the gamma-ray quasi-periodic variability of PKS 2155-304 with the latest publicly available Fermi-LAT Pass 8 data, which covers the years from 2008 August to 2016 October. We produce the light curves in two ways: the exposure-weighted aperture photometry and the maximum likelihood optimization. The light curves are then analyzed by using Lomb-Scargle Periodogram (LSP) and Weighted Wavelet Z-transform, and the results reveal a significant quasi-periodicity with a period of 1.74 ± 0.13 years and a significance of ∼4.9σ. The constraint of multifrequencies quasi-periodic variabilities on blazar emission model is discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2017
- DOI:
- 10.3847/1538-4357/835/2/260
- arXiv:
- arXiv:1611.04354
- Bibcode:
- 2017ApJ...835..260Z
- Keywords:
-
- BL Lacertae objects: individual: PKS 2155-304;
- galaxies: jets;
- gamma-rays: galaxies;
- gamma-rays: general;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 5 figures