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Figure 1: Top panel: galactic distribution of all southern hemisphere RMS sources located in the 3rd and 4th quadrants observed in 13CO and presented in this paper. The colours correspond to whether an observation resulted in a non-detection (red), a single component was detected (blue) or multiple components are detected (green). The integrated 12CO emission map of Dame et al. (2001) (grey scale) shows the Galactic distribution of molecular material. Bottom panel: galactic longitude-velocity plot showing the velocities of observed 13CO components as a function of Galactic longitude. The distribution of molecular material is shown in grey scale (again from Dame et al. 2001) for comparison. The location of the spiral arms taken from model by Taylor & Cordes (1993) and updated by Cordes (2004) are over-plotted in red. The regions covered by these observations are outlined in black (see text and Table 2 for details). |
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Figure 2:
Histograms of 1![]() ![]() |
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Figure 3: Example spectra observed towards RMS sources. The spectra presented in the top four rows have been chosen to illustrate the different kinds of emission profiles exhibited in the data and to clarify the classification scheme used for the non-Gaussian profiles. Moving left to right from the top left the profiles are classified as follows: Gaussian, red wing, blue shoulder, self-absorbed, flat-top, red asymmetic flat-top, blended and blended feature with a main and shoulder component. The bottom two rows show examples of multiple components seen towards the majority of our sample. |
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Figure 4:
Histogram of the distribution of
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Figure 5:
Histogram showing the distribution of FWHM observed towards RMS sources. The distribution peaks at ![]() |
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Figure 6:
Histogram of integrated intensity (
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Figure 7: Histograms of the Galactic latitude distribution of observed RMS sources. The unfilled histogram in each plot consists of all sources observed and reported in this paper. Histograms of the latitude distributions of the multiple component detections, single component detections and non-detections are over-plotted (grey histogram) on the left, middle and right panels respectively. A bin size of 1 degree has been used for all of these histograms. |
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Figure 8: Histogram of the number of components detected towards RMS sources reported in this paper. |
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Figure 9:
Histogram illustrating the difference between the velocities of methanol ( upper panel) and water masers ( lower panel) and the velocities of their host molecular clouds as traced by CS (see text for details). The bin size is 2 km s-1 and the total number of sources used in each plot are 233 and 148 for methanol and water masers respectively. The unfilled histogram includes all maser-CS matches within a 120
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Figure 10: Histogram showing the distribution of clouds with respected to their distance from the Galactic centre. The distribution peaks between 5 and 6 kpc consistent with the location of the 5 kpc molecular ring which surrounds the Galactic centre. The bin size used is 1 kpc. |
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