Ursini, FrancescoFrancescoUrsiniPetrucci, P. O.P. O.PetrucciBIANCHI, SimoneSimoneBIANCHIMatt, G.G.MattMiddei, R.R.MiddeiMarcel, G.G.MarcelFerreira, J.J.FerreiraCAPPI, MASSIMOMASSIMOCAPPIDe Marco, B.B.De MarcoDE ROSA, Adriano GiuseppeAdriano GiuseppeDE ROSAMalzac, J.J.MalzacMarinucci, A.A.MarinucciPONTI, GabrieleGabrielePONTITORTOSA, AlessiaAlessiaTORTOSA2025-02-242025-02-2420200004-6361http://hdl.handle.net/20.500.12386/36141<BR /> Aims: We test the two-corona accretion scenario for active galactic nuclei in the case of the "bare" Seyfert 1 galaxy HE 1143-1810. <BR /> Methods: We perform a detailed study of the broad-band UV-X-ray spectral properties and of the short-term variability of HE 1143-1810. We present results of a joint XMM-Newton and NuSTAR monitoring of the source, consisting of 5 × 20 ks observations, each separated by 2 days, performed in December 2017. <BR /> Results: The source is variable in flux among the different observations, and a correlation is observed between the UV and X-ray emission. Moderate spectral variability is observed in the soft band. The time-averaged X-ray spectrum exhibits a cut-off at ∼100 keV consistent with thermal Comptonization. We detect an iron Kα line consistent with being constant during the campaign and originating from a mildly ionized medium. The line is accompanied by a moderate, ionized reflection component. A soft excess is clearly present below 2 keV and is well described by thermal Comptonization in a "warm" corona with a temperature of ∼0.5 keV and a Thomson optical depth of ∼17 - 18. For the hot hard X-ray emitting corona, we obtain a temperature of ∼20 keV and an optical depth of ∼4 assuming a spherical geometry. A fit assuming a jet-emitting disc (JED) for the hot corona also provides a nice description of the broad-band spectrum. In this case, the data are consistent with an accretion rate varying between ∼0.7 and ∼0.9 in Eddington units and a transition between the outer standard disc and the inner JED at ∼20 gravitational radii. <BR /> Conclusions: The broad-band high-energy data agree with an accretion flow model consisting of two phases: an outer standard accretion disc with a warm upper layer, responsible for the optical-UV emission and the soft X-ray excess, and an inner slim JED playing the role of a hard X-ray emitting hot corona.STAMPAenArticle10.1051/0004-6361/2019364862-s2.0-85089096793http://arxiv.org/abs/1912.08720v1https://www.aanda.org/articles/aa/full_html/2020/02/aa36486-19/aa36486-19.html2020A&A...634A..92UFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation