A Survey of High Mass Star Forming Regions in the Lines of Deuterated Molecules

Journal article, 2020

A survey of massive star forming regions in the lines of the lowest transitions of deuterated molecules DCN, DNC, DCO+, N2D+ in the 4 mm wavelength range was performed using the 20 m radio telescope of the Onsala Space Observatory. A total of about 60 sources was observed. Lines of the DCN, DNC, and DCO+ molecules are registered in about a third of them, lines of the N2D+ molecule only in two. Estimates of the relative abundances of the molecules and deuteration degree are derived. The dependencies of these parameters and also ratios of the abundances of different deuterated molecules on temperature and velocity dispersion are analyzed. We found that the relative abundances of DCN and DNC and the DCN/HCN ratio are approximately constant in the temperature range from similar to 15 K to similar to 55 K, while relative abundance of DCO+ decreases with increasing temperature. Average ratio DCN/HCN is similar to 10(-2) for detected sources. A correlation was found between the ratios of abundances of some molecules and velocity dispersion. At the same time there are correlation between line width and temperature.