@article{10902/13812,
year = {2017},
url = {http://hdl.handle.net/10902/13812},
abstract = {Approximately 3-17 per cent of active galactic nuclei (AGNs) without detected rest-frame UV/optical broad emission lines (type-2 AGN) do not show absorption in X-rays. The physical origin behind the apparently discordant optical/X-ray properties is not fully understood. Our study aims at providing insight into this issue by conducting a detailed analysis of the nuclear dust extinction and X-ray absorption properties of two AGNs with low X-ray absorption and with high optical extinction, for which a rich set of high-quality spectroscopic data is available from XMM-Newton archive data in X-rays and XSHOOTER proprietary data at UV-to-NIR wavelengths. In order to unveil the apparent mismatch, we have determined the AV/NH and both the supermassive black hole and the host galaxy masses. We find that the mismatch is caused in one case by an abnormally high dust-to-gas ratio that makes the UV/optical emission to appear more obscured than in the X-rays. For the other object, we find that the dust-to-gas ratio is similar to the Galactic one but the AGN is hosted by a very massive galaxy so that the broad emission lines and the nuclear continuum are swamped by the star light and difficult to detect.},
organization = {IO-P and FJC acknowledge financial support through grant AYA2015-64346-C2-1-P (MINECO/FEDER). SM acknowledges financial support by the Spanish Ministry of Economy and Competitiveness through grant AYA2016-76730-P (MINECO/FEDER). AC, RD, PS and VB acknowledge financial support by the Italian Space Agency (contract ASI-INAF I/037/12/0).},
publisher = {Oxford University Press},
publisher = {MNRAS 469, 693-704 (2017)},
title = {AGNs with discordant optical and X-ray classification are not a physical family : diverse origin in two AGNs},
author = {Ordovás Pascual, Ignacio and Mateos Ibáñez, Silvia and Carrera Troyano, Francisco Jesús and Wiersema, K. and Barcons Jaúregui, Francesc Xavier and Braito, V. and Caccianiga, A. and Del Moro, A. and Della Ceca, Roberto and Severgnini, P.},
}