\begin{table}%[!h!]
%\vspace{16cm}
  \caption{\label{table:1}Properties of the first 30 out of the 11303 in the Spitzer dark
    cloud (SDC) catalogue.  The full catalogue is available at the CDS.  }
{\small 
\begin{tabular}{cccccccccccccccccc}
\hline
\hline
 Number & Name & \multicolumn{2}{c}{Coordinates}  & $I_{\rm{min}}$ &
$I_{\rm{MIR}}$& $\delta I_{\rm{MIR}}$  & $\Delta X$ &  $\Delta Y$ &
$\alpha$ &  $R_{\rm eq}$& $\tau_{\rm{peak}}$ & $\tau_{\rm{av}}$ & $\tau_{\rm{sat}}$ & Frag & \multicolumn{2}{c}{Star} & $\sigma_{\rm{star}}$\\
& & RA(J2000) & Dec(J2000)  & (MJy/sr) &(MJy/sr)   &  & (\arcsec) &  (\arcsec) & (\degr) &  (\arcsec)&  &  &  &  &Field & IRDC &(arcmin$^{-2}$) \\
\hline
 1 &        SDC9.22+0.169 & 18:05:30.40 & $-$20:53:16.0 &   37.9 &   55.7 & 0.07 &   30.0 &   20.8 & 76 &   22.6 &  1.16 &  0.50 &  4.45 &   2 & y & y &  0.92 \\
 2 &        SDC9.25+0.144 & 18:05:39.69 & $-$20:52:25.6 &   40.8 &   56.9 & 0.04 &   18.8 &   14.4 & $-$66 &   16.8 &  0.95 &  0.48 &  4.47 &   1 & y & n &  0.95 \\
 3 &       SDC9.256+0.133 & 18:05:42.92 & $-$20:52:27.8 &   41.7 &   56.7 & 0.01 &    9.3 &    7.4 & $-$42 &    9.1 &  0.85 &  0.48 &  4.47 &   1 & n & n &  1.33 \\
 4 &       SDC9.301+0.126 & 18:05:50.01 & $-$20:50:16.8 &   43.0 &   56.7 & 0.00 &   11.9 &    4.8 & $-$89 &    8.4 &  0.75 &  0.45 &  4.47 &   1 & n & n &  1.34 \\
 5 &       SDC9.328+0.031 & 18:06:14.76 & $-$20:51:39.7 &   46.2 &   60.8 & 0.02 &    7.8 &    6.9 & 87 &    7.9 &  0.74 &  0.47 &  4.53 &   1 & y & n &  1.14 \\
 6 &        SDC9.403+0.26 & 18:05:33.02 & $-$20:41:00.7 &   33.7 &   44.5 & 0.02 &    7.5 &    4.9 & $-$87 &    6.8 &  0.75 &  0.44 &  4.22 &   1 & y & n &  0.93 \\
 7 &       SDC9.432+0.163 & 18:05:58.31 & $-$20:42:21.8 &   38.7 &   51.4 & 0.03 &    9.2 &    5.8 & $-$50 &    8.1 &  0.76 &  0.44 &  4.37 &   1 & n & n &  1.02 \\
 8 &       SDC9.461+0.138 & 18:06:07.50 & $-$20:41:32.8 &   40.0 &   53.0 & 0.03 &   12.1 &    4.7 & 22 &    8.1 &  0.77 &  0.42 &  4.40 &   1 & n & n &  1.08 \\
 9 &       SDC9.624+0.187 & 18:06:16.80 & $-$20:31:35.6 &   37.7 &   53.5 & 1.58 &  227.3 &  144.0 & $-$75 &  133.4 &  4.30 &  0.61 &  4.41 &   6 & y & y &  0.78 \\
10 &       SDC9.629-0.061 & 18:07:13.25 & $-$20:38:38.7 &   38.0 &   51.7 & 0.03 &   15.9 &   11.1 & 30 &   12.5 &  0.85 &  0.45 &  4.37 &   1 & y & n &  0.94 \\
11 &       SDC9.635+0.296 & 18:05:53.87 & $-$20:27:49.8 &   24.1 &   39.7 & 0.08 &   20.6 &   10.5 & $-$60 &   15.0 &  1.96 &  0.58 &  4.11 &   1 & y & n &  0.76 \\
12 &       SDC9.689+0.000 & 18:07:06.92 & $-$20:33:41.5 &   39.6 &   52.9 & 0.01 &   17.2 &    8.2 & 57 &   11.1 &  0.79 &  0.46 &  4.40 &   1 & n & n &  1.01 \\
13 &        SDC9.692-0.55 & 18:09:10.79 & $-$20:49:34.6 &   27.2 &   35.3 & 0.02 &   12.8 &    4.7 & $-$69 &    8.7 &  0.69 &  0.41 &  3.99 &   1 & n & n &  0.94 \\
14 &       SDC9.737-0.239 & 18:08:06.57 & $-$20:38:08.1 &   37.9 &   52.1 & 0.05 &   21.2 &    8.7 & 4 &   14.1 &  0.91 &  0.48 &  4.38 &   1 & n & n &  0.97 \\
15 &       SDC9.762-0.567 & 18:09:23.29 & $-$20:46:20.9 &   26.6 &   37.3 & 0.01 &    8.2 &    5.1 & $-$48 &    7.2 &  0.98 &  0.51 &  4.05 &   1 & y & y &  0.79 \\
16 &       SDC9.787-0.156 & 18:07:54.17 & $-$20:33:06.8 &   40.1 &   61.2 & 0.06 &   41.1 &   18.4 & $-$26 &   26.0 &  1.38 &  0.57 &  4.54 &   2 & y & n &  1.13 \\
17 &       SDC9.796-0.028 & 18:07:26.89 & $-$20:28:53.3 &   43.5 &   59.8 & 0.04 &   25.6 &   12.4 & $-$1 &   18.0 &  0.92 &  0.50 &  4.52 &   1 & n & n &  1.25 \\
18 &       SDC9.798-0.707 & 18:09:59.42 & $-$20:48:32.9 &   29.1 &   40.5 & 0.36 &   44.8 &   32.1 & 2 &   33.4 &  0.90 &  0.47 &  4.13 &   1 & y & n &  0.72 \\
19 &       SDC9.819-0.141 & 18:07:54.93 & $-$20:31:00.7 &   44.8 &   62.2 & 0.02 &   27.1 &    8.7 & 37 &   14.0 &  0.95 &  0.44 &  4.56 &   1 & y & n &  1.25 \\
20 &        SDC9.825-0.03 & 18:07:30.72 & $-$20:27:26.0 &   41.0 &   58.3 & 0.08 &   55.5 &   14.0 & 78 &   23.0 &  1.02 &  0.47 &  4.49 &   2 & y & n &  1.16 \\
21 &       SDC9.844+0.752 & 18:04:38.31 & $-$20:03:31.4 &   23.1 &   30.8 & 0.05 &   16.8 &    9.5 & $-$52 &   11.8 &  0.76 &  0.43 &  3.86 &   1 & y & n &  0.56 \\
22 &       SDC9.845-0.138 & 18:07:57.47 & $-$20:29:34.3 &   37.0 &   63.5 & 0.05 &   47.7 &   24.7 & 0 &   26.4 &  2.28 &  0.51 &  4.58 &   2 & y & n &  1.16 \\
23 &       SDC9.852-0.034 & 18:07:35.07 & $-$20:26:07.8 &   30.5 &   59.3 & 0.17 &   84.0 &   39.1 & $-$73 &   53.8 &  4.95 &  0.87 &  4.51 &  12 & y & y &  1.19 \\
24 &       SDC9.859-0.746 & 18:10:15.75 & $-$20:46:27.5 &   33.1 &   61.3 & 1.94 &  208.0 &  106.2 & $-$7 &  115.0 &  3.08 &  0.79 &  4.54 &   4 & y & y &  0.63 \\
25 &       SDC9.864-0.102 & 18:07:51.78 & $-$20:27:30.2 &   49.1 &   64.5 & 0.02 &   24.4 &   12.0 & 84 &   16.2 &  0.74 &  0.44 &  4.59 &   1 & y & n &  1.18 \\
26 &       SDC9.872-0.767 & 18:10:22.02 & $-$20:46:23.9 &   42.5 &   69.3 & 1.51 &  127.6 &   80.3 & $-$66 &   89.3 &  2.29 &  0.79 &  4.67 &   2 & y & n &  0.55 \\
27 &        SDC9.878-0.11 & 18:07:55.37 & $-$20:26:58.8 &   35.5 &   65.7 & 0.07 &   41.6 &   28.7 & 26 &   34.6 &  4.98 &  0.83 &  4.61 &   4 & y & y &  1.18 \\
28 &       SDC9.889-0.747 & 18:10:19.58 & $-$20:44:56.8 &   61.7 &   99.2 & 0.20 &   18.4 &   16.2 & $-$16 &   17.3 &  2.01 &  0.92 &  5.02 &   1 & n & n &  0.59 \\
29 &       SDC9.895-0.749 & 18:10:20.74 & $-$20:44:41.4 &   73.5 &  105.0 & 0.04 &    8.5 &    4.3 & 18 &    6.7 &  1.07 &  0.54 &  5.08 &   1 & n & n &  0.57 \\
30 &       SDC9.904-0.699 & 18:10:10.70 & $-$20:42:43.9 &   58.7 &   78.9 & 0.38 &   27.5 &   13.4 & 43 &   18.7 &  0.73 &  0.47 &  4.80 &   1 & n & n &  0.49 \\
\hline
\end{tabular}}
%\begin{flushleft}
\medskip
  The columns give a running number (1),
  the name of the source based in its Galactic coordinates (2), the right
  ascension and declination (in J2000) of the cloud peak (3,4), the minimum
  8~$\mu$m emission towards the cloud ($I_{\rm{min}}$) (5), the
  8~$\mu$m emission ($I_{\rm{MIR}}$) (6), the maximum $I_{\rm{MIR}}$ variation
  within the IRDC ($\delta I_{\rm{MIR}}$, Sect.~3.3) (7), the size of the
  cloud along its major and minor axes in arcseconds (8,9), the position angle
  of the major axis of the cloud in degrees East of North (10), the equivalent
  radius ($R_{\rm{eq}}$; Sect.~\ref{sec:irdcs}) of the cloud (11), the peak and
  average optical depth of the cloud at 8~$\mu$m (12,13), the optical depth at
  8~$\mu$m at which the absorption would be saturated (14), the number of
  fragments in the cloud identified with $\tau_{\rm{step}}=0.35$ (15;
  Sect.~5.2), whether there are 24~\microns\  stars in the field (16) and in the
  cloud (17; Sect.~\ref{sec:stars}); and the density of stars around the cloud
  (18).
%\end{flushleft}
\end{table}