N2H+ and N2D+ in interstellar molecular clouds. II- Observations

Abstract

We present observations of the $J$=1--0, 2--1, and 3--2 rotational transitions of N${}_2$H${}^{+}$ and N${}_2$D${}^{+}$ towards a sample of prototypical dark clouds. The data have been interpreted using non--local radiative transfer models.

12 pages, 18 figures