The host galaxy dust extinction was modelled with Small Magellanic Cloud (SMC), Large Magellanic Cloud (LMC) or Milky Way (MW) extinction curves [@Pei92] and the X-ray absorption [in excess of the Galactic $N_{\textrm{H,Gal}}=(5.59\pm0.02)\times10^{20}$ cm$^2$; @Kalberla05] is measured from a *zphabs* model in ISIS, assuming Solar metallicity. Table \[tab4\] summarizes the fit results.\
The best fitting model is a BPL with spectral slopes $\beta_{\mathrm{X}} = 1.59\pm0.11$ and $\beta_{\mathrm{opt}} = 0.71\pm0.02$, with the cooling frequency occurring at $E_{\textrm{break}}=1.40^{+0.09}_{-0.13}$ keV in the soft X-ray range. These values are derived for SMC-like extinction (lowest $\chi^2=191.6$, for 37 degrees of freedom), while the LMC extinction curve provides a very similar fit, resulting in consistent parameter values. The MW extinction curve and its related 2175 Å bump can be excluded. The optical spectrum is reddened by dust grains at the redshift $z=2.641$ of the host galaxy, with $E(B-V)=0.06 \pm 0.01$ mag, or $A_V=0.18\pm0.03$ mag (rest-frame), modelled with an SMC-like extinction curve. We find an excess X-ray absorption of $N_\mathrm{H}=0.38^{+0.19}_{-0.17}\times 10^{22}$ cm$^{-2}$ assuming Solar metallicity, whereas $N_\mathrm{H}=2.04^{+1.03}_{-0.95}\times 10^{22}$ cm$^{-2}$ for $Z/Z_\odot=0.06$. The above errors refer to a 90 per cent confidence level. The SED results should be treated with caution, because they are dependent on the slit 