3 Results

In Table 1 all map centre coordinates and LSR velocities used are collected together with source distances (from the Sun). We here also give some relevant references to published SO, multitransition CS and outflow maps. All intensities are presented in terms of main beam brightness temperature. The SO and CS data are presented in Figs. 1-8 in terms of SO and CS integrated intensity (K $\thinspace$km $\thinspace$s^-1) contour maps. For the NGC 1333 core we have also mapped in ³⁴SO(3₂-2₁) and C³⁴S(2-1) and the integrated intensity contour maps are shown in Fig. 2. The combined contour and greyscale maps have been displayed using bicubic interpolation of the observed values.

Figure 10: CS and SO isotopomer spectra. Source name and positions as indicated

Figure 11: CS and SO isotopomer spectra. Source name and positions as indicated

Figure 12: CS and SO isotopomer spectra. Source name and positions as indicated

Figure 13: CS and SO isotopomer spectra. Source name and positions as indicated

In the case of the obvious outflow sources, NGC 2071 and Orion A, a broad Gaussian component has been subtracted from the line profile map. This is examplified in Fig. 9 for the centre positions. In the centre position of Orion A we fitted three Gaussian components to the SO line profile, a broad outflow, the hot core, and a quiescent cloud component. We obtained essentially the same result as Friberg ([1984]) although he used an additional component to describe the quiescent component. In positions adjacent to the centre position both the outflow and hot core components were removed. In the other positions, further off the centre, only a weak broad outflow component was removed when visible. The hot core component cannot be discerned in the CS spectrum (Fig. 9). Total and residual integrated intensity maps are shown for both sources in Figs. 4 and 8, respectively. These two sources were the only ones where we found prominent kinematical evidences of outflow activity in their SO and CS line profiles. In several other sources, e.g. G34.3+0.2, NGC 2264IR, and NGC 7538, there are

Figure 14: CS and SO isotopomer spectra. Source name and positions as indicated

Figure 15: The integrated intensity ratio $I[{\rm ^{34}SO}]/I[{\rm C^{34}S}]$ as function of the ratio $I[{\rm SO}]/I[{\rm CS}]$ (filled circles) for all positions in which all four isotopomers were detected. The error bars correspond to $1\,\sigma$ errors. The dotted lines are limits corresponding to the indicated abundance ratio $X[{\rm SO}]/X[{\rm CS}]$ (see text)

hints of weak wing emission in the CS data. These wings are generally weaker (if seen at all) in SO. The only exceptions are NGC 2264IR and W3(OH) where the wing emission is equally strong in CS and SO. These weak wings are not visible in the rare isotopomer data (the only exception is the C³⁴S line in Orion A).

The main isotopomer data will be used in Paper II to derive SO/CS integrated intensity ratio maps. To be able to estimate eventual SO/CS abundance ratio variations we then have observed the ³⁴SO(3₂-2₁) and C³⁴S(2-1) lines in critical positions i.e. where the SO/CS integrated intensity ratio is very high or very low. Since the SO/CS abundance ratio is estimated from the rare isotopomers we can avoid, to a large extent, effects from optical depths and possible outflows. The observed SO, ³⁴SO, CS and C³⁴S spectra are shown in Figs. 10-14 and the corresponding integrated intensities are given in Table 2. In Figs. 10-14 the C³⁴S and ³⁴SO spectra have been multiplied with a factor 5. In the cases of NGC 2071 and Orion A the residual integrated intensity is tabulated in Table 2.

In order to check the consistency of the data further we have used those entries in Table 2, for which we have reliable detections in all four isotopomers, to plot the integrated intensity ratio $I[{\rm ^{34}SO}]/I[{\rm C^{34}S}]$ as function of the ratio $I[{\rm SO}]/I[{\rm CS}]$, see Fig. 15. Here we see a clear correlation between the two ratios (as would be expected). Also shown in Fig. 15 (as dotted lines) are limits for SO/CS abundance ratios in the range 0.25 to 4.5. All data points, but one, fall in the region spanned by this range if we allow the ratios to vary within their $1\,\sigma$ errors. The error estimation of the ratios is discussed thoroughly in Paper II (Sect. 2.1) in conjunction with the ratio maps. The limits have been calculated assuming a ³²S/³⁴S ratio of 22 (Wilson & Rood [1994]) and that the SO optical depth is a factor of three lower than the optical depth of the CS line if the SO and CS abundances are equal (due to the threefold spin multiplicity of SO, see Paper II).