Astrochemistry on Galactic scales

TL;DR

This paper reviews recent advances in galactic astrochemistry, highlighting spectral surveys, isotopic studies, and cosmic ray impacts on molecular complexity and chemical evolution in the Milky Way.

Contribution

It presents new observational projects and findings on molecular diversity, isotopic ratios, and cosmic ray effects across different Galactic environments.

Findings

Rich astrochemical reservoirs in Galactic Center and star-forming regions

Isotopic ratios inform on Galactic chemical evolution

Cosmic rays significantly influence interstellar chemistry

Abstract

The increasing number of observations towards different environments in the Milky Way, as well as theoretical and experimental works, are improving our knowledge of the astrochemical processes in the interstellar medium (ISM). In this chapter we report some of the main projects to study the chemical complexity and isotopic ratios across the Galaxy. High-sensitivity spectral surveys covering broad bandwidths towards Galactic Center molecular clouds (e.g. G+0.693-0.027) and star-forming regions (e.g. the hot core G31.41+0.31) are revealing very rich astrochemical reservoirs, which include molecules of prebiotic interest. At the same time, isotopic ratios (e.g. $^{12}$C/$^{13}$C and $^{14}$N/$^{15}$N) can give important information on the Galactic chemical evolution, as well as on chemical local processes due to the physical conditions of the molecular clouds. We also highlight the role of cosmic rays as a key agent affecting the interstellar chemistry described above.