Upper limits to interstellar NH<sup>+</sup>and para-NH<sub>2</sub><sup>โ</sup>abundances
Upper limits to interstellar NH<sup>+</sup>and para-NH<sub>2</sub><sup>โ</sup>abundances
The understanding of interstellar nitrogen chemistry has improved significantly with recent results from the Herschel Space Observatory. To set even better constraints, we report here on deep searches for the NH+ ground state rotational transition J=1.5-0.5 of the ^2Pi_1/2 lower spin ladder, with fine-structure transitions at 1013 and 1019 GHz, โฆ