SIMBAD references

In this paper, a sample of 451 blazars (193 flat spectrum radio quasars (FSRQs), 258 BL Lacertae objects) with corresponding X-ray and Fermi γ-ray data is compiled to investigate the correlation both between the X-ray spectral index and the γ-ray spectral index and between the spectral index and the luminosity, and to compare the spectral indexes α_X, α_γ, α_Xγ, and α_γXγ for different subclasses. We also investigated the correlation between the X-ray and the γ-ray luminosity. The following results have been obtained. (1) Our analysis indicates that an anti-correlation exists between the X-ray and the γ-ray spectral indexes for the whole sample. However, when we considered the subclasses of blazars (FSRQs, the low-peaked BL Lacertae objects (LBLs) and the high-peaked BL Lacertae objects (HBLs)) separately, there is not a clear relationship for each subclass. For the average values, , we have (= 1.39 ± 0.35) > (= 0.97 ± 0.38) > (= 0.89 ± 0.37) ; and  (= 0.82 ± 0.23) < (= 1.12 ± 0.17) < {alpha _γ |FSRQs (= 1.41 ± 0.21) (2) For the correlations between the X-ray and the γ-ray luminosities, we have log νL_γ= (1.033±0.002)log νL_X+ (0.213±0.094) for the whole sample, log νL_γ= (0.741±0.004)log νL_X+ (12.378 ±0.162) for HBLs, and log νL_γ= (1.032±0.003)log νL_X + (0.643±0.138) for the LBLs and FSRQs; the correlation slope for HBLs is different from that for FSRQs and LBLs. For the average values, logν L_{nu }_, we have  = (44.68 ± 0.90), {logν L_X|LBLs = (44.19 ± 0.76), and logν L_X|FSRQs = (45.02 ± 0.70) for the X-ray luminosity; and logν L_γ|HBLs = (45.42 ± 0.88), logν L_γ|LBLs = (46.06 ± 0.93), and logν L_γ|FSRQs = (46.60 ± 0.86) for the γ-ray luminosity. (3) There is an anti-correlation between the effective spectral index, α_Xγ, and log νL_γ for the whole sample, and the subclasses (FSRQs, LBLs, and HBLs). The effective spectral index shows that α_Xγ|HBLs(=1.02 ± 0.12) > α_Xγ|LBLs(= 0.78 ± 0.09) ∼ α_Xγ|FSRQs (= 0.79 ±0.09). (4) For the spectral index difference, α_γXγ(=α_Xγ - α_γ) of the effective spectral index, α_Xγ, and the γ-ray spectral index, α_γ, we obtain α_γX_γ|HBLs(= 0.21 ± 0.30) > α_γX_γ|LBLs(= -0.33 ± 0.22) > α_γX_γ|FSRQs (= -0.61 ± 0.21).(5) Based on the Fermi-detected sources, we can say that the HBLs are different from FSRQs, while the LBLs are similar to FSRQs.