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Characteristic Variability Timescales in the Gamma-Ray Power Spectra of Blazars.
- Source :
-
Astrophysical Journal . 11/1/2019, Vol. 885 Issue 1, p1-1. 1p. - Publication Year :
- 2019
-
Abstract
- Characteristic variability timescales in blazar γ-ray light curves can provide insights into the physical processes responsible for γ-ray variability. The power spectral density (PSD) is capable of revealing such timescales, which may appear as breaks or periodicities. Continuous-time autoregressive moving-average (CARMA) models can be used to accurately estimate a light curve’s PSD. Through a light-curve simulation study, we develop a methodology to identify PSD breaks using CARMA models. Using this methodology, we study the γ-ray light curves of 13 bright blazars observed with the Fermi Large Area Telescope in the 0.1–300 GeV band over 9.5 yr. We present the blazar γ-ray PSDs, which provide evidence for low-frequency breaks on timescales ∼1 yr in four sources, and an additional high-frequency break on a timescale ∼9 days in one source. [ABSTRACT FROM AUTHOR]
- Subjects :
- *POWER spectra
*LIGHT curves
*SPECTRAL energy distribution
*POWER density
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 885
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Astrophysical Journal
- Publication Type :
- Academic Journal
- Accession number :
- 139450251
- Full Text :
- https://doi.org/10.3847/1538-4357/ab426a