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The rotational spectrum of silyl isocyanide (SiH$_3$NC), an isomer of the well studied silyl cyanide (SiH$_3$CN), has been detected in the laboratory in a supersonic molecular beam, and the identification was confirmed by observations of the corresponding rotational transitions in the rare isotopic species SiH$_3$$^{15}$NC and SiH$_3$N$^{13}$C. Spectroscopic constants derived from 19 transitions between $11 - 35$~GHz in the three lowest harmonically related rotational transitions in the $K = 0 ~{rm{and}}~1$ ladders of the normal isotopic species including the nitrogen nuclear quadrupole hyperfine constant, allow the principal astronomical transitions of SiH$_3$NC to be calculated to an uncertainty of about 4~km~s$^{-1}$ in equivalent radial velocity, or within the FWHM of narrow spectral features in the inner region of IRC+10216 near 200~GHz. The concentration of SiH$_3$NC in our molecular beam is three times less than SiH$_3$CN, or about the same as the corresponding ratio of the isomeric pair SiNC and SiCN produced under similar conditions. Silyl isocyanide is an excellent candidate for astronomical detection, because the spectroscopic and chemical properties are very similar to SiH$_3$CN which was recently identified in the circumstellar envelope of IRC+10216 by citet{cernicharo_discovery_2017} and of SiNC and SiCN in the same source.
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
We studied the abundance of HCN, H13CN, and HN13C in a sample of prestellar cores, in order to search for species associated with high density gas. We used the IRAM 30m radiotelescope to observe along the major and the minor axes of L1498, L1521E, an
We report the first detection of pure rotational transitions of TiO and TiO_2 at (sub-)millimeter wavelengths towards the red supergiant VY CMa. A rotational temperature, T_rot, of about 250 K was derived for TiO_2. Although T_rot was not well constr
We report the detection in TMC-1 of the protonated form of C3S. The discovery of the cation HC3S+ was carried through the observation of four harmonically related lines in the Q band using the Yebes 40m radiotelescope, and is supported by accurate ab
Methyl mercaptan (CH3SH) is a known interstellar molecule with abundances high enough that the detection of some of its minor isotopologues is promising. The present study aims at providing accurate spectroscopic parameters for the (13)CH3SH isotopol