\begin{table}%t2
%\centering
\par
\caption{\label{tab:lines}Identified lines in the RGS spectra.}
\begin{tabular}{llllrrrr}
\hline\hline\noalign{\smallskip}
\multicolumn{1}{l}{Line} &
\multicolumn{1}{l}{$E_{\rm rest}$\tablefootmark{a}~(keV)} &	
\multicolumn{1}{l}{$E_{\rm obs}$\tablefootmark{b}~(keV)} &	
\multicolumn{1}{c}{$\sigma$\tablefootmark{c}~(eV)} &	
\multicolumn{4}{c}{Detected flux\tablefootmark{d} ($10^{-6}$ photons cm$^{-2}$~s$^{-1}$) } \\
\multicolumn{1}{l}{} &
\multicolumn{1}{l}{} &	
\multicolumn{1}{l}{} &	
\multicolumn{1}{c}{} &	
\multicolumn{1}{c}{2003} &	
\multicolumn{1}{c}{2007} &
\multicolumn{1}{c}{2008} &	
\multicolumn{1}{c}{2009} \\
\noalign{\smallskip}\hline\noalign{\smallskip}
N VI f              &	0.4198  &0.4193    & 0.01		&     $ < $33.8 &	$ < $36.7 &	   $ < $31.4 &   20.3~$\pm$~8.7  \\
N VI i              &	0.4263  &0.4257    & 0.01		&     $ < $34.7 &	$ < $9.5  &	   $ < $8.7  &	  $ < $13.1      \\
N VI r              &	0.4307  &0.4301(2) & 0.01 (0$-$0.37)	&     $ < $31.4 & 24.9~$\pm$~10.7 &  29.1~$\pm$~9.9  &   22.8~$\pm$~9.0  \\
N VI He $\beta$     &	0.4980  &0.4965(3) & 0.02 (0$-$0.74)	&7.6~$\pm$~6.9  & 9.4	$\pm$4.3  &  15.4~$\pm$~5.0  &   10.6~$\pm$~5.2  \\
N VII Ly $\alpha$   &	0.5003  &0.4997(1) & 0.37 (0.26$-$0.46) &26.2~$\pm$~7.9  & 110.9~$\pm$~8.5  &  122.4~$\pm$~9.0  &   134.3~$\pm$~10.1 \\
O VII f	            &	0.5611  &0.5604    & 0.40		&19.9~$\pm$~9.6  & 28.9~$\pm$~8.6  &  37.9~$\pm$~8.9  &   51.3~$\pm$~9.8  \\
O VII i	            &	0.5686  &0.5680    & 0.40		&10.8~$\pm$~9.0  &	$ < $15.5 &  16.1~$\pm$~10.6 &   17.5~$\pm$~10.1 \\
O VII r	            &	0.5739  &0.5733(1) & 0.40 (0.04$-$0.65) &13.1~$\pm$~8.4  & 43.5~$\pm$~8.8  &  53.1~$\pm$~12.2 &   51.3~$\pm$~10.0 \\
N VII Ly $\beta$    &	0.5929  &0.5926(3) & 0    (0$-$0.77)	&     $ < $13.3 & 13.4~$\pm$~6.2  &  22.6~$\pm$~6.4  &   23.3~$\pm$~7.6  \\
N VII Ly $\gamma$   &	0.6254  &0.6247(7) & 0.63		&     $ < $9.0  &	$ < $3.7  &	   $ < $5.3  &   5.2~$\pm$~4.7  \\
N VII Ly $\delta$   &	0.6404  &0.6406(8) & 0.63		&15.3~$\pm$~5.2  &	$ < $1.7  &	   $ < $2.3  &   7.2~$\pm$~4.6  \\
O VIII Ly $\alpha$  &	0.6537  &0.6529(1) & 0.63		&40.5~$\pm$~5.8  & 130.8~$\pm$~8.0  &  167.5~$\pm$~8.4  &   177.8~$\pm$~9.9  \\
O VII He $\beta$    &	0.6656  &0.6650(5) & 0.63 (0.46$-$0.72) &9.4~$\pm$~4.9  & 14.2~$\pm$~4.9  &  8.2~$\pm$~4.9  &   16.3~$\pm$~5.5  \\
O VII He $\gamma$   &	0.6978  &0.697(2)  & 0.11		&5.1~$\pm$~4.5  &	$ < $4.1  &  6.9~$\pm$~4.3  &	  $ < $2.8       \\
Fe XVIII            &	0.7035  &0.703(1)  & 0.11		&     $ < $2.2  &	$ < $8.2  &	   $ < $7.4  &   9.8~$\pm$~4.4  \\
O VII He $\delta$   &	0.7127  &0.712(1)  & 0.11		&     $ < $8.8  &	$ < $6.1  &  5.3~$\pm$~4.0  &	  $ < $3.6       \\
Fe XVII             &	0.7252  &0.7250    & 0.11		&     $ < $13.7 & 54.1~$\pm$~10.7 &  90.9~$\pm$~12.5 &   84.9~$\pm$~13.7 \\
Fe XVII             &	0.7271  &0.7269(1) & 0.11 (0$-$0.54)	&     $ < $6.0  & 29.9~$\pm$~9.4  &  28.2~$\pm$~10.1 &   46.1~$\pm$~11.7 \\
Fe XVII             &	0.7389  &0.7380(2) & 0.25 (0$-$0.72)	&5.0~$\pm$~4.4  & 34.4~$\pm$~5.0  &  38.9~$\pm$~5.2  &   49.2~$\pm$~6.0  \\
Fe XIX              &	0.7696  &0.7658    & 0.20		&     $ < $9.1  & 5.1	$\pm$4.4  &	   $ < $9.4  &	  $ < $10.1      \\
Fe XVIII            &	0.7715  &0.7708    & 0.20		&6.7~$\pm$~5.5  & 12.3~$\pm$~5.2  &  24.9~$\pm$~5.9  &   21.5~$\pm$~6.6  \\
O VIII Ly $\beta$   &	0.7746  &0.7738(2) & 0.20 (0$-$0.86)	&     $ < $9.3  & 33.6~$\pm$~5.6  &  36.2~$\pm$~6.1  &   50.3~$\pm$~7.1  \\
Fe XVIII            &	0.7835  &0.7817(8) & 0.25		&     $ < $9.4  & 6.7	$\pm$4.1  &  5.6~$\pm$~4.3  &   7.7~$\pm$~5.1  \\
Fe XVIII            &	0.7935  &0.7929(9) & 0.25		&     $ < $2.4  &	$ < $7.1  &  8.6~$\pm$~4.0  &   5.0~$\pm$~4.5  \\
Fe XVII             &	0.8023  &0.803(1)  & 0.25		&     $ < $3.6  & 12.6~$\pm$~4.4  &  5.7~$\pm$~4.7  &	  $ < $9.9       \\
Fe XVII             &	0.8124  &0.8113    & 0.25		&     $ < $5.2  & 26.6~$\pm$~5.9  &  44.9~$\pm$~6.4  &   45.3~$\pm$~7.2  \\
O VIII Ly $\gamma$  &	0.8169  &0.8159(3) & 0.25 (0$-$0.78)	&5.1~$\pm$~4.6  & 15.5~$\pm$~6.1  &  19.8~$\pm$~6.6  &   27.3~$\pm$~7.4  \\
Fe XVII 	    &	0.8258  &0.8248(1) & 0.64 (0.23$-$0.89) &14.9~$\pm$~4.5  & 82.7~$\pm$~6.4  &  100.3~$\pm$~6.9  &   123.5~$\pm$~8.0  \\
O VIII Ly $\delta$  &	0.8365  &0.835(2)  & 1.89		&     $ < $4.9  &	$ < $4.5  &  5.2~$\pm$~5.0  &   12.5~$\pm$~5.6  \\
Fe XVIII	    &	0.8530  &0.8517(8) & 1.89		&     $ < $3.2  & 11.4~$\pm$~4.6  &  16.5~$\pm$~5.0  &   19.4~$\pm$~5.7  \\
Fe XVIII	    &	0.8626  &0.862(1)  & 1.89		&     $ < $10.0 & 11.3~$\pm$~5.5  &  18.3~$\pm$~5.5  &   13.4~$\pm$~6.0  \\
Fe XVIII	    &	0.8726  &0.8719(4) & 1.89 (1.45$-$2.35) &     $ < $9.0  & 30.7~$\pm$~5.1  &  39.9~$\pm$~5.5  &   54.6~$\pm$~6.5  \\
Fe XVII 	    &	0.8968  &0.8957    & 0.85		&5.0~$\pm$~4.7  & 13.4~$\pm$~4.5  &  17.1~$\pm$~4.9  &   14.5~$\pm$~5.5  \\
Ne IX f 	    &	0.9050  &0.9039    & 0.85		&17.0~$\pm$~6.6  & 43.5~$\pm$~7.0  &  61.8~$\pm$~7.9  &   57.7~$\pm$~8.8  \\
Ne IX i 	    &	0.9148  &0.9136    & 0.85		&     $ < $11.8 & 14.6~$\pm$~12.1 &  23.2~$\pm$~13.7 &	  $ < $30.1      \\
Fe XIX  	    &	0.9171  &0.9161    & 0.85		&     $ < $13.2 &	$ < $23.7 &	   $ < $26.3 &   38.2~$\pm$~19.0 \\
Ne IX r 	    &	0.9220  &0.9208(2) & 0.85 (0.25$-$1.23) &12.9~$\pm$~7.8  & 85.3~$\pm$~11.0 &  92.7~$\pm$~11.3 &   99.7~$\pm$~12.8 \\
Fe XX               &	0.9651  &0.965(1)  & 1.76		&     $ < $4.3  & 14.6~$\pm$~5.8  &  20.1~$\pm$~6.2  &   24.1~$\pm$~6.9  \\
Fe XVII 	    &	1.0108  &1.009(1)  & 1.76		&     $ < $9.8  & 17.8~$\pm$~6.7  &  28.1~$\pm$~7.6  &   17.7~$\pm$~8.0  \\
Ne X Ly $\alpha$    &	1.0219  &1.0205(3) & 1.76 (1.38$-$2.28) &20.8~$\pm$~7.1  & 95.3~$\pm$~9.2  &  107.0~$\pm$~9.9  &   145.3~$\pm$~11.5 \\
Ne IX He $\beta$    &	1.0740  &1.075(2)  & 3.76 (2.41$-$5.53) &9.4~$\pm$~8.0  & 16.5~$\pm$~7.3  &  24.9~$\pm$~7.3  &   24.5~$\pm$~8.0  \\
Ne IX He $\gamma$   &	1.1270  &1.124(3)  & 1.34		&     $ < $7.4  & 11.2~$\pm$~5.1  &  10.5~$\pm$~5.7  &   7.0~$\pm$~5.9  \\
Fe XVII 	    &	1.1512  &1.15(5)   & 1.34		&     $ < $5.1  & 9.8	$\pm$3.8  &  10.4~$\pm$~4.3  &   13.3~$\pm$~4.7  \\
Ne X Ly $\beta$     &	1.2109  &1.210(2)  & 1.34 (0$-$3.94)	&     $ < $10.9 &	 $ < $9.4 &	   $ < $8.3  &	  $ < $8.8       \\
Mg XI f 	    &	1.3311  &1.3297    & 2.25		&9.0~$\pm$~8.3  & 10.7~$\pm$~5.9  &  13.9~$\pm$~5.7  &   18.6~$\pm$~5.9  \\
Mg XI i 	    &	1.3431  &1.3417    & 2.25		&     $ < $11.8 &	$ < $13.0 &	   $ < $8.8  &	  $ < $7.0       \\
Mg XI r 	    &	1.3522  &1.3508(9) & 2.25 (0$-$3.73)	&     $ < $15.3 & 25.9~$\pm$~7.0  &  35.2~$\pm$~6.7  &   44.4~$\pm$~6.6  \\
Mg XII Ly $\alpha$  &	1.4726  &1.473(2)  & 4.25 (0$-$7.27)	&     $ < $15.0 & 12.7~$\pm$~4.5  &  21.1~$\pm$~5.4  &   26.6~$\pm$~5.7  \\
Mg XI He $\beta$    &	1.5793  &1.582(6)  & 5.01 (0$-$17.1 )	&12.6~$\pm$~10.0 & 5.6	$\pm$4.5  &  7.4~$\pm$~5.3  &   6.2~$\pm$~5.1  \\
Si XIII f	    &	1.8394  &1.840     & 5.38		&     $ < $31.0 &	$ < $20.9 &	   $ < $27.4 &	  $ < $27.9      \\
Si XIII i	    &	1.8537  &1.855     & 5.38		&     $ < $33.9 &	$ < $29.3 &	   $ < $4.96 &	  $ < $38.7      \\
Si XIII r	    &	1.8649  &1.865(4)  & 5.38 (0$-$15.8 )	&     $ < $36.3 & 34.4~$\pm$~11.1 &	   $ < $4.68 &   39.8~$\pm$~12.6 \\
Si XIV Ly $\alpha$  &	2.0060  &1.997(1)  & 0 (0$-$230)        &     $ < $85.6 & 22.5~$\pm$~12.4 &  19.7~$\pm$~19.4 &   18.1~$\pm$~15.8 \\
\hline
\end{tabular}
\tablefoot{All errors are for $\Delta\chi^2=2.71$ confidence range. Parameters without errors were coupled to the corresponding parameter of the following line with higher energy (see text).\\
\tablefoottext{a}{Rest energy of identified line according to ATOMDB 1.3.1. If the line is a multiplet, we give the energy of the strongest component.}\\
\tablefoottext{b}{Central energy of the fitted Gaussian.}\\
\tablefoottext{c}{Best-fit value of Gaussian sigma width.}\\
\tablefoottext{d}{Detected flux for the individual observations. For fluxes consistent with 0 at $\Delta\chi^2 \le  2.71$ only the upper limit is given.}
\vspace*{-4mm}}
\end{table}