Study of gamma-ray and near-infrared emission of gamma-ray-loud blazars object

We have collected 29 gamma-ray-loud blazars (16 BL Lac objects and 13 flat-spectrum radio quasars) with both observed near-IR and γ-ray flux densitees, with the following main results:(1)there is a very strong correlation between F γ and F IR in the low state, and a weaker but also significant correlation between F γ and F IR in the high state for 23 objects with both high and low state fluxes; (2) there is a very significant correlation between F γ and F IR in the low state, and a weak correlation between F γ and F IR in the high state for 29 sources; (3) there is a correlation between F γ and F x , but not between F γ and F 0 , and F R for both the low and high state of 26 sources; (4) there is a strong correlation between F γ and F IR in the low and high states for 15 BL Lac objects, but not for 11 flat-spectrum radio quasars. Possible constraints on the γ-ray emission mechanism are discussed.We suggest that the main gamma-ray radiation mechanism is probably the synchrotron self-Compton process.The inverse Compton scattering of the radiation from hot circumnuclear dust with T g =2000K, which is located within the region of r≈3pc, by beamed ultrarelativistic electrons is likely to be an important complementary mechanism.In addition, the γ-ray emission may be somewhat different for BL Lac objects and flat-spectrum radio quasars.