Testing the AGN Paradigm, Part I: a generic SED for Seyfert 1 galaxies

Abstract This article presents the first part of a study aimed at testing the unification paradigm for AGN (UPAGN) using the SED reconstruction code X-CIGALE. Our method consists in obtaining a generic SED for a large sample of Sy1 (Part I), then applying this SED to Sy2 (Part II), expecting that the only difference will be the line-of-sight (LOS) angle, i, relative to the polar axis of the torus of gas and dust obscuring the broad line regions (BLRs). Our sample is composed of 3,896 Type 1, SDSS Seyfert galaxies (Sy1) at low redshifts, z 0.4, separated into four spectral subgroups depending on the presence/absence in their spectra of narrow emission lines, Sy1N/Sy1B, and AGN wind, Sy1Bw and Sy1Nw. The generic SED produced by X-CIGALE applies to 90% of the Sy1 in our sample. It includes a clumpy torus with an AGN engine seen face-on (i ∼ 10○ ± 5○). Our analysis not only supports the existence of a torus in Sy1, in good agreement with UPAGN, but also reveals new facts about the accretion of matter and AGN wind: 1- a sudden accretion of matter from the BLR to the accretion disk triggered the wind, 2- matter from the wind replenishes the torus, consistent with a gradual formation of the torus by recurrent AGN winds, and 3- AGN with wind eventually evolve as AGN without wind, leaving behind a torus structure as evidence of a higher AGN activity in their past.