\begin{table}%t3 \caption{\label{specpersist}\xmm/PN and \swift/XRT spectral results for the persistent emission.} %\centerline {\tiny \begin{tabular}{lcccc} \hline \hline\noalign{\smallskip} Date$^a$& $N_{\rm H}$$^b$ & $\Gamma$ & $F_{\rm pers}$$^c$ & $\chi^2/{\rm d.o.f.}$ \\ ~ & [10$^{22}$ cm$^{-2}$] & ~ & ~ & ~ \\ \hline & & \xmm/PN & & \\ %\hline 2002 Oct. 3 & $14\pm3$ & $2.0\pm0.5$ & $1.0\pm0.2$ & $67/64$\\ ~ & $[11.9]$ & $1.6\pm0.2$ & $0.9\pm0.2$ & $68/65$\\ 2007 Feb. 27 & $11.9\pm0.2$ & $1.83\pm0.03$ & $11.60\pm0.05$ & $219/197$\\ 2007 Mar. 30 & $11.6\pm0.4$ & $1.76\pm0.08$ & $11.9\pm0.1$ & $155/200$\\ ~ & $[11.9]$ & 1.81$\pm0.04$ & $12.2\pm0.1$ & $156/201$\\ 2007 Mar. 31 & $12.1\pm0.4$ & $1.86\pm0.08$ & $12.0\pm0.1$ & $192/210$\\ ~ & $[11.9]$ & $1.83\pm0.04$ & $11.9\pm0.1$ & $192/211$\\ 2007 Apr. 1 & $12.0\pm0.3$ & $2.08\pm0.05$ & $13.6\pm0.1$ & $242/213$\\ ~ & $[11.9]$ & $2.06\pm0.02$ & $13.5\pm0.1$ & $242/214$\\ 2007 Apr. 2 & $12.5\pm0.3$ & $2.14\pm0.05$ & $13.1\pm0.1$ & $213/195$\\ ~ & $[11.9]$ & $2.04\pm0.02$ & $12.4\pm0.1$ & $225/196$\\ 2007 Apr. 3--4 & $13.1\pm0.4$ & $2.30\pm0.08$ & $5.5\pm0.1$ & $179/200$\\ ~ & $[11.9]$ & $2.08\pm0.03$ & $4.9\pm0.1$ & $204/201$\\ \hline & & \swift/XRT & & \\ %\hline 2007 Feb. 16--17 & $10.9\pm3.6$ & $1.9\pm0.7$ & $19.0\pm3.0$ & $31/28$\\ \hline \end{tabular}} \medskip $^a$~For 2007, Mar. 30 and 31 designate the periods just before and after burst~12 respectively (see Fig.~\ref{lc_pn}). Same thing for Apr.~1 and~2 and burst 13. Apr.~3--4 period is the last \xmm~revolution (rev-1340); $^b$~whenever there are brackets, the column density is frozen; $^c$~unabsorbed flux in the 2--8~keV and 2--10~keV band in units of 10$^{-11}$ \ergperseccm~for \xmm/PN and \swift/XRT, respectively. \end{table}