Open problems and perspectives offered by current and future instruments

LERMA, CNRS UMR8112, Observatoire de Paris, École Normale Supérieure and Université Pierre et Marie Curie, 24 rue Lhomond, 75231 Paris Cedex 05, France

^a e-mail: maryvonne.gerin@ens.fr

Abstract

We summarize recent observational and theoretical results and discuss the open challenges for astrochemistry and the promises offered by the current and upcoming instruments. Some of the main challenges are listed below.

• Characterization of the structure of the interstellar medium

• Coupling of the matter with magnetic fields, role of cosmic rays

• Coupling of the dynamics with the evolution of matter (chemistry, ionization degree, depletion, desorption)

• Characterization of dust grains (composition, size, emissivity, polarization)

• Evolution of the carbonaceous matter, PAHs, aggregates and Diffuse Interstellar Bands (DIBs) carriers

• Oxygen chemistry and the low abundance of molecular oxygen

• Nitrogen chemistry and its seeds, the nitrogen hydrides

• Sulfur chemistry and the contribution of S⁺ to the charge balance of translucent matter

• Neutral-neutral reactions involving simple radicals (CH, CH₂, OH, etc.).