Observational hints on the torus obscuring gas behaviour through X-rays with <i>NuSTAR</i> data

ABSTRACT According to theory, the torus of active galactic nuclei (AGN) is sustained from a wind coming off accretion disc, and for low efficient AGN, it has been proposed that such structure disappears. However, exact conditions its disappearance remain unclear. This can be studied throughout reflection component at X-rays, which associated with distant neutral material inner walls in obscured AGN. We select sample 81 AGNs observed NuSTAR distance limit D&amp;lt; 200 Mpc Eddington rate $\rm {\lambda _{Edd} \equiv L_{bol}/L_{Edd}\lt 10^{-3}}$. fit 3–70 keV spectra using model accounting partial-covering absorber plus material. find existence spans wide range black hole mass bolometric luminosities, only ?13 per cent our (11 sources) lacking any signatures. These sources fall region may L-MBH diagram. For detected component, we vast majority them are highly ($\rm {\log \ N_H \gt 23}$), {\sim 20{{\ \rm per\ cent}}}$ being Compton-thick. also an increase number unobscured tentative on ratio between {FeK\alpha }$ emission line Compton-hump luminosities toward _{Edd}=10^{-5}}$, suggesting contribution changes ratio.