Indications of Inflow Motions in Regions Forming Massive Stars
نویسنده
چکیده
Observational evidence for inflowing motions in massive star forming regions has been extremely rare. We have made a spectroscopic survey of a sample of 28 massive star forming cores associated with water masers. An optically thick line of HCN 3−2 was used in combination with optically thin lines (HCN 3−2 or CS 5−4, 3−2, and 2−1 ), to identify “blue” line profiles that can indicate inflow. Comparing intensities for 18 double-peaked line profiles yields 11 blue and 3 red profiles that are statistically significant. In the full sample of 28 sources, 12 show blue profiles and 6 show red profiles that are statistically significant based on the velocity offsets of lines that are optically thick from those that are optically thin. These results indicate that HCN 3 − 2 emission may trace inflow in regions forming high-mass stars. Subject headings: stars: formation — ISM: molecules
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