We report on the detection of hydromagnesium isocyanide, HMgNC, in the laboratory and in the carbon rich evolved star IRC+10216. The J=1-0 and J=2-1 lines were observed in our microwave laboratory equipment in Valladolid with a spectral accuracy of 3\,KHz. The hyperfine structure produced by the Nitrogen atom was resolved for both transitions. The derived rotational constants from the laboratory data are B0=5481.4333(6)\,MHz, D0=2.90(8)\,KHz, and eQq(N)=-2.200(2)\,MHz. The predicted frequencies for the rotational transitions of HMgNC in the millimeter domain have an accuracy of 0.2-0.7\,MHz. Four rotational lines of this species, J=8-7, J=10-9, J=12-11 and J=13-12, have been detected towards IRC+10216. The differences between observed and calculated frequencies are <0.5\,MHz. The rotational constants derived from space frequencies are B0=5481.49(3)\,MHz and D0=3.2(1)\,KHz, i.e., identical to the laboratory ones. A merged fit to the laboratory and space frequencies provides B0=5481.4336(4)\,MHz and D0=2.94(5)\,KHz. We have derived a column density for HMgNC of (6±2)×1011\,cm−2. From the observed line profiles the molecule have to be produced produced in the layer where other metal-isocyanides have been already found in this source. The abundance ratio between MgNC and its hydrogenated variety, HMgNC, is ≃20.
@article{arxiv.1309.0371,
title = {Laboratory and Astronomical Discovery of HydroMagnesium Isocyanide},
author = {Carlos Cabezas and Jose Cernicharo and Jose Luis Alonso and Marcelino Agundez and Santiago Mata and Michel Guelin and Isabel Peña},
journal= {arXiv preprint arXiv:1309.0371},
year = {2015}
}