Table 1: Fitting parameters of the 0.6-11.0 keV combined RGS + EPIC-pn spectrum (centre) and of the 1.4-11.0 keV EPIC-pn spectrum (right) of SAX J1808.4-3658. The continuum was modelled by a diskbb (DBB), a bbodyrad (BB) and a power law (PL). Errors on each parameter are quoted at the 90% confidence level, as for the rest of the paper.
Parameter 0.6-11.0 keV 1.4-11.0 keV
nH (1022 cm-2)a $\rm0.214^{+0.002}_{-0.003}$ $\rm0.214^{+0.002}_{-0.003}$
$kT_{\rm in}$ (keV) $\rm0.184^{+0.004}_{-0.002}$ $0.24\pm 0.01$
$N_{\rm DBB}$ ( $\times 10^3$) $\rm 36.7^{+8.2}_{-8.0}$ $\rm 15.1^{+2.7}_{-2.2}$
$kT_{\rm BB}$ (keV) $0.36\pm0.01$ $0.40\pm0.02$
$R_{\rm BB}$ (d3.5 km) $\rm 9.4^{+0.4}_{-0.3}$ $\rm 6.8^{+1.0}_{-0.9}$
$\alpha $ $\rm 2.079^{+0.006}_{-0.008}$ $\rm 2.078^{+0.007}_{-0.008}$
Edge E (keV) 0.871 (frozen)  
$\tau$ O VIII ($\times$10-2) $\rm 4.6^{+0.5}_{-0.6}$  
Line E (keV) $\rm 6.47^{+0.07}_{-0.08}$ $\rm 6.43^{+0.07}_{-0.09}$
Emissivity index $\rm -2.2_{-0.3}^{+0.2}$ $\rm -2.3^{+0.3}_{-0.2}$
$R_{\rm in}$ (GM/c2) $\rm 6.0^{+6.0}$ $\rm 8.7^{+3.7}_{-2.7}$
$R_{\rm out}$ (GM/c2) $\rm 210_{-70}^{+150}$ $\rm 207^{+111}_{-80}$
$i (^{\circ})$ >58 >67
$N_{\rm K_{\alpha}}$ ( $\times 10^{-4}$) $7.2\pm0.9$ $\rm 7.2^{+0.9}_{-0.7}$
EW (eV) $\rm 123^{+29}_{-31}$ $\rm 121^{+20}_{-16}$
F2-10 (erg/cm2/s)b $7.58(1)\times 10^{-10}$ $7.57(3)\times 10^{-10}$
$F_{\rm bol}$ (erg/cm2/s)c $4.9\times10^{-9}$ $4.5\times10^{-9}$
$\chi^2_{\rm red}$ 4293.8/3154 809.9/639
a The absorption column in the EPIC-pn spectrum was varied in the range indicated by the RGS-EPIC-pn spectrum.
b Absorbed flux in the 2.0-10.0 keV band.
c Unabsorbed flux extrapolated to the 0.05-150 keV band.


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