Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Galaxies and clusters are the ensembles of stars and other astronomical objects bound together by gravitational forces. Galaxies are ordered into galaxy groups, which are in turn organised into clusters. The Earth is in a galaxy called the Milky Way, which is in the Local Group in the Virgo Supercluster.
Ten stars in the Large Magellanic Cloud exhibit very low elemental abundances, suggesting that they have experienced enrichment by the earliest generations of stars only. These stars provide a window into a distant region of the high-redshift universe.
JWST detections of Si, C and Fe absorption lines in a bright z = 9.31 galaxy with a two-component clump structure suggest that mergers contributed to the rapid build-up of mass and chemical enrichment soon after the Big Bang.
An analysis of eight ultra-faint galaxies during the epoch of reionization with absolute magnitudes between −17 mag and −15 mag shows that most of the photons that reionized the Universe come from dwarf galaxies.
A dynamical model using the spatially resolved kinematics of galaxies in the CALIFA survey shows that galaxy assembly depends on both the stellar mass and the dynamical mass (which includes stars plus dark matter).
Volker Springel created the original GADGET code more than 25 years ago. Now it supports some of the largest simulations in astrophysics, and is being developed to do vastly more.
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.
It’s been an eventful year for robotic missions. From probes of Solar System bodies to large-scale cosmic structures, advances in our understanding of the formation and evolution of the Universe gather speed.
