\begin{table}%T1
\caption{Data on observed fields of M~31.}
\label{tab:data}
%\centerline
{\small$$
\begin{tabular}{rcr@{ ... }rr@{ ... }rrcc}
\hline\hline
%\noalign{\smallskip}
Field  &Quadrant  &\multicolumn{2}{c}{$X$-extent}
       &\multicolumn{2}{c}{$Y$-extent} &Number
       &\multicolumn{2}{c}{Mean rms noise}\\
\#     &in M~31 &\multicolumn{2}{c}{} &\multicolumn{2}{c}{}
       &of spectra &in $I_{1-0}$  &per channel\\
       &  &\multicolumn{2}{c}{(\arcmin)} &\multicolumn{2}{c}{(\arcmin)}
       & &$\rm (K~ km~ s^{-1})$ &(mK)$^{1)}$\\
%\noalign{\smallskip}
\hline%\noalign{\smallskip}
 1  &S  &$-$48.5&$-$33.3  &$-$10.1&14.0     &162~980  &0.45 &34\\
 2  &SW &$-$34.0&$-$13.9  &$-$18.1&$-$2.0   &225~122  &0.38 &37\\
 3  &SE &$-$34.0&$-$13.9  &2.0&16.1         &115~765  &0.35 &34\\
 4  &SW &$-$14.2&5.1      &$-$17.0&$-$3.0   &128~027  &0.44 &33\\
 5  &NE &21.0&39.3        &$-$2.0&16.1      &204~190  &0.46 &32\\
 6  &NW &21.0&39.1        &$-$19.6&$-$1.5   &152~630  &0.25 &22\\
 7  &NE &39.0&55.9        &$-$2.0&15.1      &160~045  &0.27 &21\\
 8  &NW &38.9&56.1        &$-$19.6&$-$1.5   &117~198  &0.29 &27\\
 9  &NE &3.0&21.1         &$-$2.0&18.0      &164~760  &0.32 &25\\
10  &SE &$-$14.1&3.2      &$-$3.0&17.0      &128~534  &0.27 &27\\
11  &NW &4.8&21.1         &$-$19.0&$-$1.0   &128~156  &0.33 &24\\
12  &NW &2.8&5.1          &$-$3.0&$-$1.8    &666     &0.36 &26\\[1.5mm]%\hline
%\noalign{\medskip}
%\\& & & & & & & & \\
    &NE &\multicolumn{2}{c}{$X>0$} &\multicolumn{2}{c}{$Y>0$}
        &528~995 &\hspace{0.5em} 0.36$^{2)}$ &\quad 26$^{2)}$\\
    &NW &\multicolumn{2}{c}{$X>0$} &\multicolumn{2}{c}{$Y<0$}
        &398~650  &0.29  &24\\
    &SE &\multicolumn{2}{c}{$X<0$} &\multicolumn{2}{c}{$Y>0$}
        &339~371  &0.35  &31\\
    &SW &\multicolumn{2}{c}{$X<0$} &\multicolumn{2}{c}{$Y<0$}
        &421~057  &0.41  &35\\
%\noalign{\smallskip}
\hline
%\noalign{\smallskip}
 &Total &\multicolumn{4}{l}{3512 square arcminutes}  &1~688~073
      &0.35 &29\\
\hline
\end{tabular}$$}
\medskip
$^{1)}$ Temperatures are on $T_{\rm mb}$-scale,
   where $T_{\rm mb} = 1.15 T_{\rm A}^*$.
   $^{2)}$ Weighted means.
\end{table}