Volume 8 Issue 3, March 2024

Binary neutron star mergers are complex to understand astrophysically. A small piece of the puzzle may now have been solved using a computationally intensive simulation to explain how short gamma-ray bursts can be launched by a magnetar engine.

The size distribution of solid grains in dense clouds is a key parameter to constrain in order to understand grain growth, which influences the nature and timescale of the formation of protoplanets. A JWST study has quantified the grain size distribution by modelling the spectral absorptions arising from ice components of grains before protostellar collapse.

The Lyman-α emission line of hydrogen should be absorbed and thus not seen from galaxies in the early Universe — and yet it is observed. Now detailed images from JWST coupled with magnetohydrodynamical simulations show that interactions between galaxies are facilitating the escape of this radiation.

The dark surface of Mercury can be explained by <1 wt% of microcrystalline graphite and similar amounts of Fe⁰. Low-reflectance materials may be secondary crust and carbon was not completely drained from the mantle during early differentiation.

Fe/Ni and Fe/Co ratios in iron meteorites indicate that the earliest inner Solar System planetesimals were oxidized and water-bearing, having formed beyond the point at which water condensed in the solar protoplanetary disk.

A dynamo mechanism similar to that in the Sun can produce the large-scale magnetic field that is needed to drive the relativistic outflows (and short gamma-ray burst) from binary neutron star mergers, according to a numerical relativity simulation.

When stars like our Sun die, they expel their outer layers in a dramatic stellar wind. This study of an unusual chemical signature in one particular stellar wind reveals that the signature is due to the presence of a binary system whose components had a close approach around 200 years ago.

Nuclear experiments become the latest ‘messenger’ to help with unravelling the mysteries of neutron stars. Combining information from astronomical observations and laboratory experiments reveals how nucleons interact in both nuclei and stars.

A hyperactive fast radio burst source has been observed for thousands of hours using relatively small telescopes. The energy distribution of the brightest bursts detected suggests a possible link between repeating and apparently non-repeating burst sources.

Multiwavelength observations of a galactic nucleus exhibit quasi-periodic X-ray eruptions (QPEs) that repeat every 22 days, a timescale intermediate between those of other QPEs and so-called repeating nuclear transients. The eruptions are likely to be driven by the interaction between an orbiting body and a central massive black hole.

Cold ice-covered dust grains grow during their journey from the interstellar medium to protoplanetary disks. JWST observations show that this growth begins before the protostellar phase and provide quantitative insights into the grain growth process.

Chemical abundances derived from infrared nebular lines reveal strongly depressed metallicities in interacting galaxies, suggesting that in luminous infrared galaxies chemical enrichment and stellar-mass growth take place through mergers, which drive these galaxies out of equilibrium.

Researchers have detected the elusive dark matter component of cosmic filaments near the Coma galaxy cluster using gravitational lensing. This supports the idea that galaxy clusters grow at the intersection of cosmic filaments, shedding light on the structure of our universe.

A combination of JWST/NIRCam observations and magnetohydrodynamic simulations indicates that frequent mergers with close companions give rise to bursty star formation and hence the unexpectedly high Lyman-α emission detected from early galaxies.