Day-Scale Variability of 3C 279 and Searches for Correlations in Gamma-Ray, X-Ray, and Optical Bands
Abstract
Light curves of 3C 279 are presented in optical (R band), X-rays (RXTE/PCA), and γ rays (CGRO/EGRET) for 1999 January-February and 2000 January-March. During both of those epochs the γ-ray levels were high and all three observed bands demonstrated substantial variation, on timescales as short as 1 day. Correlation analyses provided no consistent pattern, although a rather significant optical/γ-ray correlation was seen in 1999, with a γ-ray lag of ~2.5 days, and there are other suggestions of correlations in the light curves. For comparison, correlation analysis is also presented for the γ-ray and X-ray light curves during the large γ ray flare in 1996 February and the two γ-bright weeks leading up to it; the correlation at that time was strong, with a γ-ray/X-ray offset of no more than 1 day.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2001
- DOI:
- 10.1086/322462
- arXiv:
- arXiv:astro-ph/0105247
- Bibcode:
- 2001ApJ...558..583H
- Keywords:
-
- Gamma Rays: Observations;
- Galaxies: Quasars: Individual: Alphanumeric: 3C 279;
- Astrophysics
- E-Print:
- 20 pages, including 7 figures