Description
The determination of isotopic ratios in interstellar molecules is a powerful probe of chemical routes leading to their formation. In particular the ^14^N/^15^N abundance ratio of nitrogen-bearing species provides information on possible fractionation mechanisms. Up to now there is no accurate determination of this ratio in the ISM for the amidogen radical, NH_2_. This work aimed at determining rotational frequencies of ^15^NH_2_ in order to enable its astronomical detection, which will help to understand the formation mechanisms of nitrogen hydrides in the ISM. Complementary synchrotron-based broadband far-infrared and high resolution submillimeter-wave frequency measurements have been performed to investigate the pure rotational spectrum of the ^15^NH_2_ species. The first spectroscopic study of the ^15^N-isotopologue of the amidogen radical yielded an accurate set of molecular parameters. Accurate frequencies are now available for ^15^NH_2_ up to 7THz (with N''>=13) and dedicated astronomical searches can be undertaken.
|