Marinucci, A.Bianchi, S.Matt, G.Alexander, D. M.Baloković, M.Bauer, F. E.Brandt, W. N.Gandhi, P.Guainazzi, M.Harrison, F. A.Iwasawa, KazushiKoss, M.Madsen, K. K.Nicastro, F.Puccetti, S.Ricci, C.Stern, D.Walton, D. J.2019-01-302019-01-302016-020035-8711https://hdl.handle.net/2445/127741We present a NuSTAR and XMM-Newton monitoring campaign in 2014/2015 of the Comptonthick Seyfert 2 galaxy, NGC 1068. During the 2014 August observation, we detect with NuSTAR a flux excess above 20 keV (32 ± 6 per cent) with respect to the 2012 December observation and to a later observation performed in 2015 February. We do not detect any spectral variation below 10 keV in the XMM-Newton data. The transient excess can be explained by a temporary decrease of the column density of the obscuring material along the line of sight (from NH 1025 cm−2 to NH = 6.7 ± 1.0 × 1024 cm−2), which allows us for the first time to unveil the direct nuclear radiation of the buried active galactic nucleus in NGC 1068 and to infer an intrinsic 2-10 keV luminosity LX =7+7−4×1043 erg s−1.1 p.application/pdfeng(c) Marinucci, A. et al., 2016Galàxies activesObservacions astronòmiquesActive galaxiesAstronomical observationsinfo:eu-repo/semantics/article6699702019-01-30info:eu-repo/semantics/openAccess