Correlation between the gamma-ray and the near-infrared emissions from gamma-ray-loud blazars in the lowstate

We have studied the correlations between the near-IR and the gamma-ray bands using 29 observed gamma-ray-loud blazars (16 BL Lac objects and 13 flat-spectrum radio quasars (FSRQs)) with near-IR and gamma-ray spectral indices and fluxes. The results show that there are very strong correlations between near-IR mean spectral index alpha(IR) and gamma-ray mean spectral index alpha(gamma) and between near-IR and gamma-ray fluxes. Which means that gamma-ray radiation from the blazars should be mainly produced by the synchrotron self-Compton process. In addition, the gamma-ray emission of BL Lac objects may be somewhat different from flat-spectrum radio quasars.