2025MNRAS.543.4254R

This article presents the first part of a study aimed at testing the unification paradigm for active galactic nucleus (UPAGN) using the spectral energy distribution (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 3896 Type 1, Sloan Digital Sky Survey (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, AGN wind, Sy1Bw, and Sy1Nw. The generic SED produced by X-CIGALE applies to 90 per cent of the Sy1 in our sample. It includes a clumpy torus with an AGN engine seen face-on ($i \sim 10^\circ \pm 5^\circ$). 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 disc 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.