This review discusses the molecular ion and its deuterated isotopomers. The ion is important because of its fundamental nature, astrophysical significance and dynamical richness. The following topics are discussed: the discovery of H l , its unusual bonding and the important role played by ab initio electronic-structure calculations; the formation of H: and its importance in models of the inter...

We studied the compaction of microporous vapor-deposited ice films under irradiation with different ions in the 80Y400 keVenergy range.We found that porosity decreases exponentially with irradiation fluence, with amean compaction area per ion that scales linearlywith the stopping power of the projectile S above a threshold St 1⁄4 4 eV8 . The experiments roughly follow a universal dependence of ...

Aromaticmolecules (PAHs or others) are considered to be an abundant component of the Interstellar Matter. However, their formation process remains a problem since a high production rate is required in order to balance the destruction mainly caused by shocks in the Interstellar Medium. We propose that catalytic reactions, based on organometallic chemistry could contribute efficiently to the form...

The 13 C substitutions of molecule HC 7 N were observed in TMC-1 using the J = 12 − 11, J = 13 − 12 rotational transitions in the frequency range 12.4 to 13.6 GHz. We present the first detection the 13 C isotopic species of HC 7 N in the interstellar medium, based on the average of a number of weak rotational transitions. This paper describes the calibration and data averaging process that is a...

Nitrogen-substituted polycyclic aromatic hydrocarbons (NPAHs) have been proposed to play a key role in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest building block - the aromatic pyridine molecule - has remained elusive for decades. Here we reveal a potential pathway to a facile pyridine (C5H5N) synthesis via the reaction of the cyano...

The largest noncyclic molecules detected in the interstellar medium (ISM) are organic with a straight-chain carbon backbone. We report an interstellar detection of a branched alkyl molecule, iso-propyl cyanide (i-C3H7CN), with an abundance 0.4 times that of its straight-chain structural isomer. This detection suggests that branched carbon-chain molecules may be generally abundant in the ISM. Ou...

Abst rm Over 60 molecules and ions, most of them organic, have been detected in interstellar space and most are thought to be formed by gas phase ion molecule reactions. The unique features of reactions of this type, which allow them to proceed readily under the extreme conditions of space and yet exhibit great selectivity and otherwise resemble reactions in solution, are discussed and illustra...

Fullerenes have been recently detected in various circumstellar and interstellar environments, raising the question of their formation pathway. It has been proposed that they can form at the low densities found in the interstellar medium by the photo-chemical processing of large polycyclic aromatic hydrocarbons (PAHs). Following our previous work on the evolution of PAHs in the NGC 7023 reflect...