1995A&A...303..554Z

We analyze further the observational data for dense cores in regions of high mass star formation (HMSF) obtained recently with the SEST and Metsaehovi radio telescopes. The statistical distributions of the core sizes, masses, mean densities, CS line widths and CO temperatures are constructed. To reduce the influence of the selection effects we consider separately also a subsample which includes the cores located within 3kpc from the Sun. The size distribution peaks sharply at its lower edge (∼1pc). The mass spectrum for M>1000M_☉ can be fitted by the power law (dN/dM∝M^–1.7 for the 3kpc subset). The galacto-centric dependences of these parameters in the range R≃7-11kpc are investigated. There is a trend to a systematic decrease of the mean density of the cores with increasing galacto-centric distance. We have attempted to investigate the radial dependences of some physical parameters in several cores which have a simple structure. The CS line areas drop rather quickly with r, corresponding to r^–1.5 to r^–2. The CS line widths decrease towards the core edges as well, sometimes below the C³⁴S line width (measured at the CS peak position). The ratios of the CS and C³⁴S line widths and intensities are described preferably by the models with density inhomogeneities in the cores. We investigate the L-{DELTA}V and L-n relationships for the CS cores. Although there is a trend for increasing line width with increasing size the correlation is very weak. There is in general a higher velocity dispersion in HMSF cores than in CO clouds and dense cores in dark clouds. We suggest that the L-n data imply an upper limit to the mean density depending on the size.