Correlation Study of TeV Blazars in Optical Band and γ-ray Band

Multi band correlation analysis is of great significance to the study of the physical model and radiation mechanism of Blazars. In order to study the physical model of TeV Blazars, we search and sort out their γ-ray band data and optical band data according to the names and coordinates of their counterparts of 78 TeV Blazars in the 4FGL-DR3 catalogue, and find that there are 56 TeV Blazars with both optical band and γ-ray band data. The Discrete Correlation Function (DCF) is used to calculate the correlation between the optics and γ-ray of each Blazar. The calculation results show that 20 sources show weak γ-ray-optical correlation, 30 sources show strong γ-ray-optical correlation, and 6 sources show no γ-ray-optical correlation. Among sources that exhibit strong correlation, there is also varying degrees of time delay between the optical and γ-ray bands. These results support that the high-energy photons of TeV Blazar mainly come from synchronous self Compton radiation of lepton model. However, we also find that there are some “orphan flares” in both the optical and γ-ray bands, which may indicate that the source of low energy photons is not unique.