Aims. We describe the assignment of a previously unidentified interstellar absorption line to ArH and discuss its relevance in the context of hydride absorption in diffuse gas with a low H2 fraction. The confidence of the assignment to ArH is discussed, and the column densities are determined toward several lines of sight. The results are then discussed in the framework of chemical models, with...

The crossed molecular beam reactions of the ground-state silylidyne radical (SiH; XΠ) with allene (H2CCCH2; XA1) and D4-allene (D2CCCD2; X A1) were carried out at collision energies of 30 kJ mol−1. Electronic structure calculations propose that the reaction of silylidyne with allene has no entrance barrier and is initiated by silylidyne addition to the π electron density of allene either to one...

In the last few decades, astronomers have found that interstellar clouds are chemical factories, in which atoms are processed into more complex chemical species in reactions energized by starlight and fast particles. Many of the identified molecules are formed in networks of ion-molecule and neutral-neutral reactions and, at the low temperatures in the interstellar medium (-15 K), can accrete o...

With the 30-m IRAM radio telescope, we observed several massive star forming regions at wavelengths of 3–4 and 2 mm. The temperature gas in sources was estimated from lines CH3CCH transitions NH3 molecule obtained during observations 100-m telescope Effelsberg. As a result, correlation between integrated intensity ratios J = 1−0 H13CN–HN13C kinetic has been obtained. results allow us to propose...

Zusammenfassung Since the discovery of a cold molecular component of the interstellar medium in the 1970s, it has been realized that most of the dark clouds are actually molecular clouds, consisting mainly of molecular hydrogen and some amount of dust and other molecules. Nowadays, molecular clouds are recognized as places of star-formation in the Milky Way and other galaxies. Therefore, studie...