Víctor Rivilla | Searcharxiv

arXiv2025

The role of supernova remnants for the emergence of pre-biotic chemistry in molecular clouds

There is growing evidence that the Sun might have formed within a nebula impacted by at least one SNR. In this scenario, ejecta and shocks from SNRs may have provided the elements on which life as we know it is based. Investigating the chemical complexity of molecular clouds impacted by SNRs is therefore essential to unveil the star formation process and how life appeared on Earth. In this paper, we exploit this scientific questions and describe which technical specifications will drive in future generation telescopes.

astro-ph.GA↗

arXiv2020

Isomers in Interstellar Environments (I): The Case of Z- and E-Cyanomethanimine

In this work, we present the results of our investigation into the chemistry of Z- and E-cyanomethanimine (HNCHCN), both of which are possible precursors to the nucleobase adenine. Ab initio quantum chemical calculations for a number of reactions with atomic hydrogen were carried out. We find that the reaction H + Z/E-HNCHCN leading both to H-addition as well as H$_2$-abstraction proceed via similar short-range barriers with bimolecular rate coefficients on the order of $\sim10^{-17}$ cm$^{3}$ s$^{-1}$. These results were then incorporated into astrochemical models and used in simulations of the giant molecular cloud G+0.693. The calculated abundances obtained from these models were compared with previous observational data and found to be in good agreement, with a predicted [Z/E] ratio of $\sim3$ - somewhat smaller than the previously derived value of $6.1\pm2.4$. We find that the [Z/E] ratio in our simulations is due mostly to ion-molecule destruction rates driven by the different permanent dipoles of the two conformers. Based on these results, we propose a general rule-of-thumb for estimating the abundances of isomers in interstellar environments.

astro-ph.GA↗