\begin{table}%t1
\par
\caption {\label{table:log}Log of \R\ and \S\ observations and best-fit 
  spectral parameters of the persistent emission. An absorbed power-law model is used to fit these spectra.} 
%\centerline
 {\begin{tabular}{ccccclllc} 
\noalign{\smallskip} 
\hline 
\hline 
\noalign{\smallskip} 
Instrument  &  Date  & Exp. & \nh\ & $\Gamma$ & Flux$_{\rm 2{-}10~ keV}^{a}$ 
& Flux$_{\rm 2{-}20~ keV}^{a}$ & Flux$_{\rm 0.3{-}100~ keV}^{a}$ & $\chi^{2}_{\rm red}$\\ 
&  MJD   &  ks  &  $10^{22}$ cm$^{-2}$ & & erg cm$^{-2}$ 
s$^{-1}$ & erg cm$^{-2}$ s$^{-1}$ & erg cm$^{-2}$ s$^{-1}$ &\\ 
\hline 
\noalign{\smallskip} 
\S$^{b}$ & 54628.66385 & $0.4$ & $4.0^{\rm +0.7}_{-0.6}$ & $2.2^{\rm +0.3}_{-0.3}$ 
& $2.8\pm0.3$e-10 & $3.7\pm0.5$e-10 & $10.2\pm2$e-10 & 0.8 \\  
\R\ & 54633.24637 & $2.0$ & $3.4^{\rm +1.2}_{-2}$ & $2.4^{\rm +0.1}_{-0.2}$ 
& $4.5\pm0.4$e-10 & $5.6\pm0.4$e-10 & $17.5\pm7$e-10 & 1.2 \\ 
\R\ & 54634.42452 & $2.5$ & $3.4^{\rm +1.2}_{-1.2}$ & $2.4^{\rm +0.1}_{-0.2}$ 
& $3.4\pm0.2$e-10 & $4.3\pm0.2$e-10 & $12.8\pm2$e-10 & 0.7 \\ 
\R\ & 54635.27545 & $2.0$ & $3.3^{\rm +2.1}_{-2.2}$ & $2.2^{\rm +0.1}_{-0.2}$ 
& $2.7\pm0.2$e-10 & $3.6\pm0.2$e-10 & $9.4\pm1.6$e-10 & 0.8 \\ 
\R\ & 54638.80878 & $3.5$ & $3.4^{\rm +0.8}_{-0.9}$ & $2.2^{\rm +0.1}_{-0.1}$ 
& $1.9\pm0.1$e-10 & $2.6\pm0.1$e-10 & $6.8\pm1.1$e-10 & 0.9 \\ 
\R\ & 54639.85563 & $3.0$ & $3.4^{\rm +0.7}_{-0.7}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $2.1\pm0.1$e-10 & $2.8\pm0.1$e-10 & $7.8\pm1.4$e-10 & 1.2 \\ 
\R\ & 54640.90230 & $3.5$ & $3.5^{\rm +0.7}_{-0.7}$ & $2.2^{\rm +0.1}_{-0.1}$ 
& $1.9\pm0.1$e-10 & $2.6\pm0.1$e-10 & $7.1\pm1.1$e-10 & 1.2 \\ 
\S$^{b,c}$ &  54664.62684 & $0.6$ & $3.1^{\rm +0.4}_{-0.4}$ & $1.9^{\rm +0.2}_{-0.2}$ 
& $4.9\pm0.3$e-10 & $7.2\pm0.6$e-10 & $18.3\pm3$e-10 & 1.1 \\ 
\R\ & 54665.10546 & $3.0$ & $3.7^{\rm +1.2}_{-2}$ & $2.6^{\rm +0.2}_{-0.1}$ 
& $4.9\pm0.6$e-10 & $5.9\pm0.7$e-10 & $20.0\pm4$e-10 & 1.6 \\ 
\R\ & 54669.24527 & $1.8$ & $2.9^{\rm +1.2}_{-2}$ & $2.5^{\rm +0.2}_{-0.2}$ 
& $4.8\pm0.8$e-10 & $5.8\pm0.9$e-10 & $18.0\pm3$e-10 & 1.6 \\ 
\R\ & 54670.99462 & $3.3$ & $3.9^{\rm +1.2}_{-2}$ & $2.5^{\rm +0.1}_{-0.2}$ 
& $5.5\pm0.7$e-10 & $6.5\pm0.6$e-10 & $23.2\pm4$e-10 & 1.5 \\ 
\R\ & 54672.97638 & $1.7$ & $4.1^{\rm +1.2}_{-2}$ & $2.7^{\rm +0.2}_{-0.2}$ 
& $4.9\pm0.5$e-10 & $5.8\pm0.6$e-10 & $21.5\pm5$e-10 & 1.3 \\ 
\R\ & 54674.73749 & $1.8$ & $4.2^{\rm +1.2}_{-2}$ & $2.7^{\rm +0.2}_{-0.3}$ 
& $4.6\pm0.7$e-10 & $5.5\pm0.6$e-10 & $20.8\pm5$e-10 & 1.6 \\ 
\S$^{b,d}$ &  54674.94054 & $0.1$ & $3.4^{\rm +0.4}_{-0.4}$ & $2.0^{\rm +0.4}_{-0.4}$ 
& $7.3\pm0.5$e-10 & $8.3\pm0.6$e-10 & $23.3\pm4$e-10 & 1.4 \\ 
\R\ & 54677.47471 & $3.5$ & $4.2^{\rm +1.1}_{-1.2}$ & $2.6^{\rm +0.3}_{-0.2}$ 
& $4.5\pm0.7$e-10 & $5.3\pm0.8$e-10 & $18.3\pm3$e-10 & 1.2 \\ 
\R\ & 54678.59119 & $3.3$ & $4.4^{\rm +2.2}_{-1}$ & $2.3^{\rm +0.3}_{-0.1}$ 
& $4.3\pm0.7$e-10 & $5.0\pm0.8$e-10 & $17.5\pm4$e-10 & 1.5 \\ 
\R\ & 54679.63915 & $3.2$ & $4.1^{\rm +1.2}_{-2}$ & $2.7^{\rm +0.2}_{-0.3}$ 
& $4.0\pm0.5$e-10 & $5.1\pm0.6$e-10 & $14.9\pm5$e-10 & 1.3 \\ 
\R\ & 54680.29712 & $2.1$ & $2.9^{\rm +1.2}_{-1.4}$ & $2.5^{\rm +0.2}_{-0.3}$ 
& $3.7\pm0.5$e-10 & $4.3\pm0.6$e-10 & $13.2\pm3$e-10 & 1.5 \\ 
\R\ & 54681.86101 & $3.5$ & $3.6^{\rm +1.2}_{-2}$ & $2.3^{\rm +0.2}_{-0.2}$ 
& $3.3\pm0.5$e-10 & $3.7\pm0.6$e-10 & $14.7\pm3$e-10 & 1.1 \\ 
\R\ & 54682.71212 & $7.0$ & $2.3^{\rm +0.9}_{-0.9}$ & $2.5^{\rm +0.1}_{-0.1}$ 
& $1.5\pm0.04$e-10 & $1.9\pm0.05$e-10 & $6.5\pm1.4$e-10 & 1.1 \\ 
\R\ & 54683.89045 & $3.5$ & $2.2^{\rm +1.2}_{-1.2}$ & $2.2^{\rm +0.1}_{-0.2}$ 
& $0.95\pm0.07$e-10 & $1.2\pm0.5$e-10 & $3.4\pm0.6$e-10 & 0.8 \\ 
\R\ & 54684.93786 & $1.8$ & $2.2^{\rm +0.9}_{-1}$ & $2.2^{\rm +0.2}_{-0.2}$ 
& $0.89\pm0.03$e-10 & $1.4\pm0.3$e-10 & $3.2\pm0.5$e-10 & 0.9 \\ 
\R\ & 54685.80434 & $1.6$ & $2.0^{\rm +1.0}_{-0.6}$ & $2.2^{\rm +0.1}_{-0.1}$ 
& $0.84\pm0.06$e-10 & $1.1\pm0.07$e-10 & $3.0\pm0.6$e-10 & 1.2 \\ 
\R\ & 54686.31211 & $2.5$ & $1.3^{\rm +0.9}_{-0.4}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $0.94\pm0.06$e-10 & $1.2\pm0.6$e-10 & $3.5\pm0.8$e-10 & 0.8 \\ 
\R\ & 54687.04156 & $0.7$ & $4.0^{\rm +2}_{-2}$ & $2.5^{\rm +0.2}_{-0.2}$ 
& $1.2\pm0.1$e-10 & $1.5\pm0.2$e-10 & $5.2\pm1.2$e-10 & 0.7 \\ 
\R\ & 54687.35989 & $2.7$ & $2.7^{\rm +1.2}_{-1.2}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $1.1\pm0.06$e-10 & $1.5\pm0.06$e-10 & $4.4\pm0.9$e-10 & 1.3 \\ 
\R\ & 54687.43638 & $2.2$ & $2.7^{\rm +1.3}_{-1.3}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $1.1\pm0.07$e-10 & $1.4\pm0.08$e-10 & $4.4\pm1.0$e-10 & 1.5 \\ 
\R\ & 54688.34471 & $2.4$ & $2.7^{\rm +1.2}_{-1.2}$ & $2.4^{\rm +0.1}_{-0.1}$ 
& $1.2\pm0.05$e-10 & $1.6\pm0.05$e-10 & $4.9\pm2$e-10 & 1.2 \\ 
\R\ & 54690.23786 & $2.2$ & $2.3^{\rm +1.1}_{-1.0}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $1.4\pm0.06$e-10 & $1.9\pm0.1$e-10 & $5.5\pm1$e-10 & 1.4 \\ 
\R\ & 54691.67712 & $1.8$ & $1.9^{\rm +1.1}_{-1.0}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $1.5\pm0.07$e-10 & $2.0\pm0.07$e-10 & $5.6\pm1.5$e-10 & 1.6 \\ 
\R\ & 54692.13508 & $1.6$ & $1.7^{\rm +1}_{-1}$ & $2.2^{\rm +0.1}_{-0.1}$ 
& $1.5\pm0.07$e-10 & $2.0\pm0.06$e-10 & $5.6\pm1.1$e-10 & 1.3 \\ 
\R\ & 54692.74785 & $1.2$ & $3.1^{\rm +1.3}_{-1.3}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $1.8\pm0.07$e-10 & $2.3\pm0.1$e-10 & $6.8\pm1.2$e-10 & 1.3 \\ 
\R\ & 54696.71397 & $0.5$ & $3.2^{\rm +2}_{-1.5}$ & $2.3^{\rm +0.1}_{-0.1}$ 
& $2.1\pm0.1$e-10 & $2.8\pm0.2$e-10 & $8.2\pm1.6$e-10 & 1.1 \\ 
\hline  
\end{tabular} }
\par
\smallskip
${^a}$~Unabsorbed flux; $^{b}$~\S/XRT was operating in WT mode; $^{c,d}$
intermediate long and short pre-burst persistent emission, respectively.  
\end{table}