A Study of the Broad-band Spectral Indeices of Gamma-ray-loud Blazars

Using the broad-band spectral indeices of 66 gamma-ray-loud blazars in their high states, we studied the possible correlations between different broad-band spectral indeices. We also studied the possible correlations between different broad-band spectral indices of BL Lac objects and flat-spectrum radio quasars (FSRQs), respectively. (1)Strong correlations were found between α_{r, ir} and α_{ir, γ}, between α_{r, ir} and α_{o, γ}, between, α_{r, o} and α_{o, x}, and between α_{r, o} and α_{o, γ} in the high states for our blazar sample. (2)Strong anti-correlations were found between α_{r, x} and α_{x, γ} in the high states for our blazar sample. (3)For flat-spectrum radio quasars (FSRQs) strong correlations found between α_{r, o} and α_{o, x}, and between α_{r, o} and α_{o, γ} in the high states. (4)For BL Lac objects strong correlations were found between α_{r, o} and α_{o, γ}, between α_{r, x} and α_{x, γ} and between α_{ir, x} and α_{x, γ} in high states. (5)Beased on these results, we suggest that the γ-ray emission is probably from the Self-Compton process.