2018/02/15 by Xu-Liang Fan, Shao-Kun Li, Shaokun Li +10
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Light curve #Luminosity #Optics #Physics #Quasar #Radiation #Spectral index #Spectral line #Spitzer Space Telescope #Telescope #Variation (astronomy) #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/aab09d
accepted for publication in The Astrophysical Journal, 5 figures, 2 tables
arxiv created 2018/02/15 · openalex publication_date 2018/03/20 · arxiv updated 2018/04/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We present our photometric monitoring of a flat spectrum radio quasar 3C 454.3 at Yunnan observatories from 2006 to 2011. We find that the optical color of 3C 454.3 shows an obvious redder-when-brighter trend, which reaches a saturation stage when the source is brighter than 15.15 mag at V band. We perform a simulation with multiple values of disk luminosity and spectral index to reproduce the magnitude–color diagram. The results show that the contamination caused by the disk radiation alone is difficult to produce the observed color variability. The variability properties during the outburst in 2009 December are also compared with γ -ray data derived from the Fermi γ -ray space telescope. The flux variation of these two bands follows a linear relation with , which provides observational evidence for the external Compton process in 3C 454.3. Meanwhile, this flux correlation indicates that electron injection is the main mechanism for the variability origin. We also explore the variation of the flux ratio F γ / F R and the detailed structures in the light curves, and discuss some possible origins for the detailed variability behaviors.