Eighteen sources displayed CS emission greater than 3\(\sigma\). A typical spectrum is shown in Figure \ref{N92spectrum}. Emission lines were fit using fitgauss, the standard Gaussian fitting routine in GBTIDL. Fitting parameters (amplitude in T\(_{mb}\) units, central velocity and FWHM) are listed in Table \ref{fitting}. For sources that displayed a double peak, two simultaneous Gaussian functions were fit to the emission and are listed in consecutive rows. Column densities were calculated assuming local thermal equilibrium, optically thin emission and an excitation temperature T\(_{ex}\)=15 K, a typical ISM value (see review in \citet{Zinnecker_2007}). Increasing or decreasing the assumed excitation temperature by 5 K changes the column density by about 30%. If CS(1-0) is optically thick, as we assume for three sources in section 4.2 below, then our calculation would be a lower limit. Given these assumptions we used the following relation (see \citet{Miettinen_2012} for a detailed discussion of the relations below): \[N_{CS} = \frac{3 k_B \epsilon_0}{2 \pi^2}\frac{1}{\nu \mu^2_{el}S}\frac{Z_{rot}(T_{ex})}{g_K g_I}\frac{e^{E_u/k_B T_{ex}}}{1-\frac{F(T_{bg})}{F(T_{ex})}}\int T_{MB}dv\] where \[\begin{aligned} g_K= g_I &=& 1\\ \mu^2_{el} S &=& 3.8 Debye^2\\ Z_{rot} &=& .8556\; T_{ex}-0.10\\ F(T) &=& \frac{1}{e^{h\nu/k_BT}-1}.\\\end{aligned}\] The dipole moment line strength (\(\mu^2_{el}\) S) is taken from the JPL spectral line catalog \cite{PICKETT_1998}. The partition function (Z\(_{rot}\)) is a linear fit to JPL data between T=37 to 75 K. T\(_{bg}\) was taken to be the cosmic microwave background temperature, 2.725 K. The uncertainty in the fit amplitudes and derived column densities is dominated by our flux-calibration uncertainty. Since the relationships are linear, we estimate the uncertainty in both as 20%.
\label{fitting}
| Name | l (\(^\circ\)) | b (\(^\circ\)) | T\(_{mb}\) (K) | Vel\(_{LSR}\) (km/s) | FWHM (km/s) | N\(_{CS}\) (x10\(^{14}\) cm\(^{-2}\)) |
|---|---|---|---|---|---|---|
| N62-1 | 34.352 | 0.192 | 1.3 | 57.6 | 0.9 | 3.4\(\times\)10\(^{14}\) |
| 3.5 | 56.4 | 1.2 | 1.3\(\times\)10\(^{15}\) | |||
| N62-2 | 34.329 | 0.195 | 1.1 | 57.2 | 1.9 | 6.1\(\times\)10\(^{14}\) |
| N65-1 | 35.044 | 0.327 | 1.6 | 51.3 | 1.7 | 8.1\(\times\)10\(^{14}\) |
| N65-2 | 35.025 | 0.350 | 2.4 | 50.4 | 2.2 | 1.6\(\times\)10\(^{15}\) |
| 10.9 | 53.3 | 4.1 | 1.3\(\times\)10\(^{16}\) | |||
| N65-4 | 35.049 | 0.330 | 2.2 | 51.3 | 1.9 | 1.1\(\times\)10\(^{15}\) |
| N77-1 | 40.437 | -0.044 | 3.1 | 68.0 | 1.6 | 1.4\(\times\)10\(^{15}\) |
| N77-2 | 40.422 | -0.024 | 4.1 | 69.5 | 2.6 | 2.9\(\times\)10\(^{15}\) |
| N82-5 | 42.125 | -0.623 | 5.7 | 66.4 | 1.8 | 2.9\(\times\)10\(^{15}\) |
| N90-1 | 43.788 | 0.083 | 1.2 | 35.2 | 0.7 | 2.1\(\times\)10\(^{14}\) |
| N90-2 | 43.792 | 0.089 | 1.0 | 36.0 | 0.6 | 1.4\(\times\)10\(^{14}\) |
| 2.6 | 35.4 | 0.6 | 3.9\(\times\)10\(^{14}\) | |||
| N92-2 | 44.349 | -0.803 | 1.3 | 61.6 | 1.4 | 5.8\(\times\)10\(^{14}\) |
| N92-3 | 44.334 | -0.818 | 1.9 | 61.3 | 2.6 | 1.5\(\times\)10\(^{15}\) |
| N117-3 | 54.107 | -0.044 | 2.3 | 40.9 | 1.7 | 1.2\(\times\)10\(^{15}\) |
| 3.8 | 38.4 | 2.3 | 2.7\(\times\)10\(^{15}\) | |||
| N123-2 | 57.578 | -0.284 | 2.3 | -9.3 | 1.9 | 1.4\(\times\)10\(^{15}\) |
| N133-1 | 63.125 | 0.442 | 1.0 | 20.7 | 2.2 | 7.0\(\times\)10\(^{14}\) |
| N133-2 | 63.132 | 0.415 | 1.4 | 19.3 | 2.2 | 7.3\(\times\)10\(^{14}\) |
| N133-3 | 63.179 | 0.440 | 1.4 | 23.3 | 2.2 | 7.4\(\times\)10\(^{14}\) |
| N133-4 | 63.152 | 0.441 | 1.5 | 24.0 | 4.6 | 1.7\(\times\)10\(^{15}\) |
| 3.2 | 23.3 | 1.8 | 1.4\(\times\)10\(^{15}\) |
Gaussian fitting parameters for CS detections.
The three mapped regions are shown as boxes overlaid on the GLIMPSE 8 \(\mu\)m images in Figures \ref{N56map}-\ref{N77map}. The maps were cropped to just those regions showing emission above 3\(\sigma\). The regions containing emission were then exported to a FITS file using custom-built IDL tools. The FITS-format datacubes were then analyzed using CASA. The standard moment maps (total intensity, average velocity and velocity width) are shown next to the corresponding 8 \(\mu\)m emission images in Figures \ref{N56map}-\ref{N77map}.