© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical SocietyMatzeu, G. A.Nardini, E.Parker, M. L.Reeves, J. N.Braito, V.Porquet, D.Middei, R.Kammoun, E.Lusso, E.Alston, W. N.Giustini, M.Lobban, A. P.Joyce, A. M.Igo, Z.Ebrero, J.Ballo, L.Santos Lleó, M.Schartel, N.Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-07372021-04-132021-04-132020-07-15Monthly Notices of the Royal Astronomical Society 497(2): 2352–2370(2020)0035-8711https://academic.oup.com/mnras/article-abstract/497/2/2352/5871831http://hdl.handle.net/20.500.12666/299We present joint XMM-Newton and NuSTAR observations of the 'bare' narrow-line Seyfert 1 Ton S180 (z = 0.062), carried out in 2016 and providing the first hardX-ray view of this luminous galaxy. We find that the 0.4-30 keV band cannot be self-consistently reproduced by relativistic reflection models, which fail to account simultaneously for the soft and hard X-ray emission. The smooth soft excess prefers extreme blurring parameters, confirmed by the nearly featureless nature of the Reflection Grating Spectrometer (RGS) spectrum, while the moderately broad Fe K line and the modest hard excess above 10 keV appear to arise in a milder gravity regime. By allowing a different origin of the soft excess, the broad-band X-ray spectrum and overall spectral energy distribution (SED) are well explained by a combination of (a) direct thermal emission from the accretion disc, dominating from the optical to the far/extreme UV; (b) Comptonization of seed disc photons by a warm (kT(e) similar to 0.3 keV) and optically thick (tau similar to 10) corona, mostly contributing to the soft X-rays; (c) Comptonization by a standard hot (kT(e) greater than or similar to 100 keV) and optically thin (tau < 0.5) corona, responsible for the primary X-ray continuum; and (d) reflection from the mid/outer part of the disc. The two coronae are suggested to be rather compact, with R-hot less than or similar to R-warm less than or similar to 10 r(g). Our SED analysis implies that Ton S180 accretes at super-Eddington rates. This is a key condition for the launch of a wind, marginal (i.e. 3.1 sigma significance) evidence of which is indeed found in the RGS spectrum.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttps://creativecommons.org/licenses/by-nc-nd/4.0/Black hole physicsGalaxies: activeGalaxies: individual: Ton S180Galaxies: nucleiX rays: galaxiesinfo:eu-repo/semantics/article10.1093/mnras/staa20761365-2966http://dx.doi.org/10.13039/501100000781http://dx.doi.org/10.13039/501100000780http://dx.doi.org/10.13039/501100003981http://dx.doi.org/10.13039/501100005184http://dx.doi.org/10.13039/100012818http://dx.doi.org/10.13039/100000104info:eu-repo/semantics/openAccess