Using Long-term Optical-Infrared Color Variability to Probe the Disk-Jet Connection in Blazars
Abstract
We undertook a 5 year, multiwavelength program to observe a sample of blazars in various Fermi $\gamma$-ray states, using the Small and Medium Aperture Research Telescope System (SMARTS) 1.3 m + ANDICAM instrument in Cerro Tololo, Chile. We present near daily, optical-infrared (OIR) color variability to constrain competing emission in the OIR wavebands, presumably from the accretion disk and highly variable jet. The main results of previous short-term color variability studies are reproduced in most cases, namely that BL Lacs are bluer when brighter and FSRQs are redder when brighter. However, we extend this interpretation by providing a self-consistent way to explain blazars that did not behave as predicted by the existing dichotomy in blazar color variability. We show that over long timescales, patterns emerge in the OIR color variability that are not seen on shorter timescales due to the selection effects introduced by only observing blazars in $\gamma$-ray flaring states. By observing a large sample of blazars on up to 5 year timescales, we show that these short-term color variability 'snapshots' can be incorporated into a more comprehensive understanding of blazar OIR color variability, and by extension the contribution of non-thermal jet flux in the OIR regime. Finally, we address how long-term OIR color variability can constrain the disk-jet interaction in blazars.
- Publication:
-
American Astronomical Society Meeting Abstracts #224
- Pub Date:
- June 2014
- Bibcode:
- 2014AAS...22441003I