\begin{table}%t2 \par \caption{\label{tab2}PSD model fitting results.} \small%\centering \par \begin{tabular}{llccccccccc} \hline \hline \noalign{\smallskip} \multicolumn{1}{l}{PSD} & \multicolumn{1}{l}{Model} & \multicolumn{1}{c}{$A$\tablefootmark{a}} & \multicolumn{1}{c}{$\alpha$} & \multicolumn{1}{c}{$C$} & \multicolumn{1}{c}{$\nu_{\rm b}$} & \multicolumn{1}{c}{$\alpha_l$} & \multicolumn{1}{c}{$\alpha_h$} & \multicolumn{1}{c}{$f_{\rm L}$} & \multicolumn{1}{c}{$R$} & \multicolumn{1}{c}{$\chi^2/$d.o.f.} \\ & & (Hz$^{-1}$) & & (Hz$^{-1}$) & ($\times 10^{-6}$~Hz) & & & ($\times 10^{-5}$~Hz) & (\%) & \\ \noalign{\smallskip} \hline \noalign{\smallskip} {\it XMM}/soft & PL~ & $18^{\rm +4}_{-3}$ & $2.30\pm 0.14$ & $0.14\pm 0.01$ & -- & -- & -- & -- & -- & 43.6/42 \\ \noalign{\smallskip} {\it XMM}/soft & PL+L & $13^{\rm +7}_{-6}$ & $2.24\pm 0.20$ & $0.14\pm 0.01$ & -- & -- & -- & $8.2^{\rm +4.9}_{-2.1}$ & $4.9\pm 2.5$ & 34.9/40 \\ \noalign{\smallskip} {\it XMM}/hard & PL~ & $19^{\rm +4}_{-3}$ & $2.11\pm 0.18$ & $0.94\pm 0.05$ & -- & -- & -- & -- & -- & 41.2/42\\ \noalign{\smallskip} \rxte+{\it XMM} & BPL~ & $64^{\rm +24}_{-8}$ & -- & $0.94$\tablefootmark{b} /906\tablefootmark{c} & $6.7^{\rm +4.4}_{-2.9}$ & $0.40\pm 0.17$ & $2.21^{\rm +0.24}_{-0.20}$ & -- & -- & 51.7/53 \\ \noalign{\smallskip} \hline \end{tabular} \tablefoot{Following Lampton \etal\ (\cite{Lampton1976}), all errors indicate the 68\% confidence intervals, for 3, 5 and 4 parameters of interest in the case of the PL, BPL~and PL+L models, respectively.\\ \tablefoottext{a}{PL~normalization which is equal to the PSD value at $10^{-4}$~Hz. In the case of the BPL~model, $A$ is defined as in Eq.~(2).} \tablefoottext{b}{Poisson noise level for the ``high-frequency'' part of the PSD. This value is equal to the best-fit value of the PL~model fit to the \xmm\ hard band PSD, and it was kept constant during the model fit. } \tablefoottext{c}{Expected Possion noise level for the low-frequency, \rxte\ part of the PSD.} } \end{table}