Observational hints on the torus obscuring gas behaviour through X-rays with NuSTAR data

According to theory, the torus of active galactic nuclei (AGN) is sustained from a wind coming off the accretion disc, and for low efficient AGN, it has been proposed that such structure disappears. However, the exact conditions for its disappearance remain unclear. This can be studied throughout the reflection component at X-rays, which is associated with distant and neutral material at the inner walls of the torus in obscured AGN. We select a sample of 81 AGNs observed with NuSTAR with a distance limit of D23⁠), with ∼20 per cent being Compton-thick. We also find an increase in the number of unobscured sources and a tentative increase on the ratio between FeKα emission line and Compton-hump luminosities toward λEdd=10−5⁠, suggesting that the contribution of the FeKα line changes with Eddington ratio. © 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical SocietyThis research has made use of the NASA/IPAC Extragalactic Data base (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of data and/or software provided by the High Energy Astrophysics Science Archive Research Center (HEASARC), which is a service of the Astrophysics Science Division at NASA/GSFC and the High Energy Astrophysics Division of the Smithsonian Astrophysical Observatory. NOC would like to thank CONACyT scholarship No. 897887. CVC acknowledges support from CONACyT. We thank the UNAM PAPIIT project IN105720 (PI OGM). LHG acknowledges funds by ANID – Millennium Science Initiative Program – ICN12_009 awarded to the Millennium Institute of Astrophysics (MAS).With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.Peer reviewe