The Spectral Energy Distributions of Fermi Blazars

Abstract

(Abridged) In this paper, multi-wavelength data are compiled for a sample of 1425 Fermi blazars to calculate their spectral energy distributions (SEDs). A parabolic function, $\log(νF_ν) = P_1(\logν- P_2)^2 + P_3,$ is used for SED fitting. Synchrotron peak frequency ($\log ν_p$), spectral curvature ($P_1$), peak flux ($ν_{\rm p}F_{\rm ν_p}$), and integrated flux ($νF_ν$) are successfully obtained for 1392 blazars (461 flat spectrum radio quasars-FSRQs, 620 BL Lacs-BLs and 311 blazars of uncertain type-BCUs, 999 sources have known redshifts). Monochromatic luminosity at radio 1.4 GHz, optical R band, X-ray at 1 keV and $γ$-ray at 1 GeV, peak luminosity, integrated luminosity and effective spectral indexes of radio to optical ($α_{\rm RO}$), and optical to X-ray ($α_{\rm OX}$) are calculated. The "Bayesian classification" is employed to log$ν_{\rm p}$ in the rest frame for 999 blazars with available redshift and the results show that 3 components are enough to fit the $\logν_{\rm p}$ distribution, there is no ultra high peaked subclass. Based on the 3 components, the subclasses of blazars using the acronyms of Abdo et al. (2010a) are classified, and some mutual correlations are also studied. Conclusions are finally drawn as follows: (1) SEDs are successfully obtained for 1392 blazars. The fitted peak frequencies are compared with common sources from samples available (Sambruna et al. 1996, Nieppola et al. 2006, 2008, Abdo et al. 2010a). (2) Blazars are classified as low synchrotron peak sources (LSPs) if $\logν_{\rm p}$(Hz) $\leq 14.0$, intermediate synchrotron peak sources (ISPs) if $14.0 < \logν_{\rm p}$(Hz) $\leq 15.3$, and high synchrotron peak sources (HSPs) if $\logν_{\rm p}$(Hz) $> 15.3$. (3) $γ$-ray emissions are strongly correlated with radio emissions. (...)