\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}