\begin{table}%t3
 \caption{Line widths measured in data set~1 (coronal hole) at two positions above the solar limb, and the associated ion temperatures.}\label{tab results data set 1}
\small%\centerline
 {
    \begin{tabular}{l c c c c c  c c }
       \hline
       \hline
      %&&&&&&&& \\[-8pt] 
           &      
           & \multicolumn{3}{c}{57\arcsec{} ($n_{\rm e}=4.8 \times 10^7~{\rm cm}^{-3}, 
             \xi=15~{\rm km} ~ {\rm s}^{-1}$)} 
           & \multicolumn{3}{c}{102\arcsec{} ($n_{\rm e}=2.7 \times 10^7~{\rm cm}^{-3}, 
             \xi=17~{\rm km} ~ {\rm s}^{-1}$)} \\
       Line$^{{a}}$ & $q/m^{{b}}$ 
          & Observed width$^{{c}}$ &  Width$^{{d}}$  & $T_i^{{e}}$ 
          & Observed width$^{{c}}$ &  Width$^{{d}}$  & $T_i^{{e}}$ \\
       {} & {} & (\AA) & (\AA) & ($10^6$~K) & (\AA) & (\AA) & ($10^6$~K) \\ 
       \hline
       \ion{Fe}{x}   1028.02 &  0.16 
         	&  0.1111 $\pm$ 0.004  &  0.1102 $\pm$ 0.004 &  5.96 $\pm$ 0.70 
         	&  0.1161 $\pm$ 0.004  &  0.1184 $\pm$ 0.004  &  6.76 $\pm$ 0.80  \\
       \ion{Fe}{x}   1463.50  &  0.16 
         	&  0.1434 $\pm$ 0.004  &  0.1435 $\pm$ 0.013  &  4.87 $\pm$ 1.15    
          &        \ldots        &        \ldots        &       \ldots      \\
       \ion{Fe}{xi}   1467.08 &  0.18 
         &  0.1310 $\pm$ 0.004  &  0.1272 $\pm$ 0.007  &  3.64 $\pm$ 0.62    
         &  0.1376 $\pm$ 0.004  &  0.1318 $\pm$ 0.011  &  3.73 $\pm$ 1.00  \\
       \ion{Ar}{viii}   700.26$^\ast$  &  0.18 
         &  0.1158 $\pm$ 0.004  &  0.1351 $\pm$ 0.002  &  3.35 $\pm$ 0.36                                &  0.1222 $\pm$ 0.005  &  0.1411 $\pm$ 0.004  &  3.53 $\pm$ 0.58  \\
       \ion{Ar}{viii}    713.82$^\ast$  &  0.18 
         &  0.1291 $\pm$ 0.004  &           \ldots        &  2.88 $\pm$ 0.34    
         &        \ldots        &        \ldots        &       \ldots      \\
       \ion{Fe}{xii}   1242.00 &   0.20 
         &  0.1035 $\pm$ 0.004  &  0.1039 $\pm$ 0.004  &  3.34 $\pm$ 0.50    
         &  0.1132 $\pm$ 0.004  &  0.1128 $\pm$ 0.004  &  3.83 $\pm$ 0.59  \\
       \ion{Fe}{xii}   1349.36  & 0.20 
          &  0.1071 $\pm$ 0.004  &  0.1078 $\pm$ 0.004  &  2.98 $\pm$ 0.45    
          &  0.1176 $\pm$ 0.004  &  0.1177 $\pm$ 0.004  &  3.46 $\pm$ 0.55  \\
       \ion{Ca}{x}    574.00$^\ast$  & 0.22 
          &  0.1111 $\pm$ 0.004  &  0.1118 $\pm$ 0.002  &  3.43 $\pm$ 0.42    
          &  0.1137 $\pm$ 0.004  &  0.1185 $\pm$ 0.002  &  3.76 $\pm$ 0.49  \\
       \ion{Si}{viii}   1445.75  & 0.25 
          &  0.1605 $\pm$ 0.004  &         \ldots         &  3.24 $\pm$ 0.27    
          &  0.1674 $\pm$ 0.004  &         \ldots       &  3.44 $\pm$ 0.31  \\
       \ion{S}{x}   1196.20  & 0.28 
          &  0.1250 $\pm$ 0.004  &          \ldots       &  3.23 $\pm$ 0.35    
          &  0.1266 $\pm$ 0.004  &           \ldots      &  3.19 $\pm$ 0.39  \\
       \ion{N}{v}   1238.81  & 0.29 
          &  0.1532 $\pm$ 0.004  &  0.1709 $\pm$ 0.004  &  2.60 $\pm$ 0.18    
          &  0.1448 $\pm$ 0.004  &  0.1804 $\pm$ 0.004  &  2.86 $\pm$ 0.21  \\
       \ion{O}{vi}   1031.93  & 0.31 
          &  0.1426 $\pm$ 0.004  &          \ldots        &  2.98 $\pm$ 0.24    
          &  0.1406 $\pm$ 0.004  &          \ldots      &  2.82 $\pm$ 0.26  \\
       \ion{Mg}{ix}    706.05$^\ast$  & 0.33 
          &  0.1669 $\pm$ 0.004  &  0.1669 $\pm$ 0.002  &  3.22 $\pm$ 0.25    
          &  0.1775 $\pm$ 0.004  &  0.1795 $\pm$ 0.002  &  3.67 $\pm$ 0.29  \\
       \ion{Na}{ix}    681.72$^\ast$  & 0.35 
          &  0.1561 $\pm$ 0.004  &  0.1587 $\pm$ 0.002  &  2.94 $\pm$ 0.24    
          &  0.1535 $\pm$ 0.004  &  0.1637 $\pm$ 0.002  &  3.06 $\pm$ 0.27  \\
       \ion{Si}{xi}    580.91$^\ast$   & 0.36 
          &  0.1269 $\pm$ 0.004  &  0.1271 $\pm$ 0.002  &  3.13 $\pm$ 0.32    
          &  0.1251 $\pm$ 0.004  &  0.1204 $\pm$ 0.002  &  2.66 $\pm$ 0.34  \\
       \ion{Si}{xi}    604.15$^{\ast, {f}}$   & 0.36 
          &  0.1229 $\pm$ 0.005  &          \ldots        &  2.66 $\pm$ 0.31    
          &  0.1313 $\pm$ 0.005  &          \ldots         &  2.97 $\pm$ 0.40  \\
       \ion{Mg}{x}    624.94$^\ast$   & 0.37 
          &  0.1477 $\pm$ 0.004  &  0.1485 $\pm$ 0.002  &  3.26 $\pm$ 0.28    
          &  0.1513 $\pm$ 0.004  &  0.1524 $\pm$ 0.002  &  3.35 $\pm$ 0.31  \\
       \hline
    \end{tabular}}
  \medskip
$^{{a}}$ Wavelengths in angstroms are taken from \citet{Feldman97}. Lines marked with an asterisk are observed in second order. \\ 
$^{{b}}$ Ion charge-to-mass ratio. \\
$^{{c}}$ Half-width at 1/$\sqrt{e}$ (Gaussian). Instrumental width is removed, but spectra are not corrected from the instrumental stray light. For lines seen in second order, the widths are twice as large as what would be measured in first order (see Sect.~\ref{sec Signatures of preferential heating}). \\
$^{{d}}$ Half-width at 1/$\sqrt{e}$ when spectra are corrected from the stray light, with the instrumental width removed. \\
$^{{e}}$ Ion temperature deduced from the corrected line width, with the non-thermal velocity removed. When no correction was necessary or possible, the observed width was used. \\ 
$^{{f}}$ This line is blended with an \ion{Fe}{vii}~line, as given by \citet{Ekberg03}. See comments in Sect.~\ref{sec correction from the instrumental stray light}. 
\end{table}