The Optical-X-Ray Gamma-Ray Spectral Energy Distributions of Gev Gamma-Ray Loud Blazars and Connection Among LBs, HBLs and FSRQs

In this paper, we introduce a new composite spectral indices α_γxγ = α_xγ - α_γ, and prove α _{γ x γ }^ob = α _xγ ^ob - α _γ = α _{γ x}ⁱⁿ - α _γ = α _{γ x γ }ⁱⁿ, that means α_γxγ is intrinsic. We plot a α_xox - α_γxγ diagram for 25 Gev γ-ray blazars for which α_x and α_γ have been provided in the literature, where α_xox = α_ox-αx which was introduced by Sambruna et al. (1996) and proved that it is intrinsic by our previous paper (Xie et al. 2001). Using this new composite color color (α_xox - α_γxγ) diagram, we investigated the nature of the HBLs LBLs relationship, and the BL Lacs FSRQs relationship, in high-energy emission. The results show that the spectral energy distributions of three subclasses of Gev γ-ray loud blazars are different, but essentially continuous: HBLs and FSRQs occupy separated regions while LBLs bridge the gap between HBLs and FSRQs. The results are consistent with that derived from a low energy color color(α_xox - α_oro) diagram by Sambruna et al. (1996) and Xie et al. (2001). However, on the α_ox - α_xγ diagram, FSRQs, LBLs and HBLs occupy same region. Because both α_γxγ and α_xox are intrinsic, thus, the new connection among HBLs, LBLs and FSRQs obtained by us is intrinsic.