The radiation from stars and active galactic nuclei (AGNs) creates photodissociation regions
(PDRs) and X-ray-dominated regions (XDRs), where the chemistry or heating is dominated …

Since we intend to review experimental and theoretical studies of physicochemical
processes occurring on cosmic dust grains in very cold regions in space, we start with a brief …

Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium
can be initiated by the methyl cation CH3+ (refs.,–), but so far it has not been observed …

The James Webb Space Telescope (JWST, Gardner et al. 2006) is a 6.5 m space telescope
launched in 2021 December and is developed by the National Aeronautics and Space …

Our main knowledge about astrophysical environments relies on radiative spectra.
Absorption studies require background sources that are located hapharzadly in …

We present a multiline survey of the interstellar medium (ISM) in two z> 6 quasar host
galaxies, PJ231− 20 (z= 6.59) and PJ308− 21 (z= 6.23), and their two companion galaxies …

Abstract The Orion Bar is the archetypal edge-on molecular cloud surface illuminated by
strong ultraviolet radiation from nearby massive stars. Our relative closeness to the Orion …

Interstellar hydrides—that is, molecules containing a single heavy element atom with one or
more hydrogen atoms—were among the first molecules detected outside the solar system …

Context. JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging
observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the …

Molecular hydrogen is the most abundant molecular species in the universe. While no
doubts exist that it is mainly formed on the interstellar dust grain surfaces, many details of …