Nature Astronomy, Published online: 29 September 2026; doi:10.1038/s41550-026-02969-5 The formation process of polycyclic aromatic hydrocarbons (PAHs) at very low metallicity is uncertain. The detection of PAHs in a 7% solar metallicity galaxy, along with emission from compact clumps and small grain sizes, helps elucidate the mechanisms at play.
Nature Astronomy, Published online: 29 September 2026; doi:10.1038/s41550-026-02993-5 The discovery of an unusually metal-poor galaxy overdensity that may preserve the chemical fingerprints of the first stars in the Universe provides a new way to investigate how the earliest stellar generations formed.
This investigation aims to test the validity of general relativity (GR) on kiloparsec scales via galaxy-scale strong gravitational lensing (SGL) combined with multiple cosmological probes. To circumvent the circularity problem induced by the presumption of a cosmological model based on GR, we apply the distance sum rule in the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric to constrain the post-Newtonian paramete…
Nature Astronomy, Published online: 28 September 2026; doi:10.1038/s41550-026-02979-3 New observations provide a more robust observational test of tidal torque theory while revealing an unexpected puzzle for galaxy formation.
Abstract As a new probe, weak lensing (WL) peak steepness statistics are sensitive to the density profile of halos, which encodes important information about baryonic feedback and dark matter properties, leading to a promising means to statistically constrain these effects using WL data. In this article, we present its first application to Hyper Suprime-Cam Year 1 data to demonstrate the great potential of these new…
Nature Astronomy, Published online: 28 September 2026; doi:10.1038/s41550-026-02989-1 Modern observatories such as JWST and ALMA are revealing dynamically mature galaxies early in cosmic history. A century after Hubble, galaxy morphology is becoming a probe of galaxy-formation physics, including gas accretion, star formation and feedback.
Abstract We explore the joint probe on the baryonic feedback effect using the weak-lensing measurement from the upcoming Chinese Space Station Survey Telescope (CSST) photometric survey and the dispersion measure (DM) statistics of the fast radio bursts (FRBs) from next-generation radio telescopes, i.e., the Square Kilometre Array (SKA) and the Deep Synoptic Array 2000 (DSA-2000). By employing the baryonic halo mode…
Galaxy clusters are the most powerful strong lenses; they greatly magnify the flux of distant and faint sources. Strong lensing also allows for the reconstruction of their mass distribution with sim1% accuracy and enables the investigation of cosmological parameters. The number of known systems of this type is bound to increase in the coming years thanks to wide imaging surveys. Using simulations in this context is…
L. Leuzzi, Massimo Meneghetti, Alexandre Adam, Lauro Moscardini, C. Giocoli, P. Bergamini, Yashar Hezaveh, Matteo Maturi, Amata Mercurio, A. Moretti, A. A. Plazas, Rosati P
Nature Astronomy, Published online: 25 September 2026; doi:10.1038/s41550-026-02977-5 The jury is out as to whether dark energy is best described by a cosmological constant or as dynamical. This Perspective presents both sides of the case and considers the questions that need to be addressed going forward.
The Euclid mission has been designed to provide, as one of its main deliverables, information on the nature of the gravitational interaction, which determines the expansion of the Universe and the formation of structures. Thus, Euclid has the potential to test deviations from general relativity that will allow us to shed light on long-lasting problems in the standard cosmological Λ cold dark matter model, łcdm. Eucl…
Noemi Frusciante, M. Martinelli, Lucas Lombriser, A. Silvestri, Maria Archidiacono, Marco Baldi, M. Ballardini, N.Bartolo, Emilio Bellini, Giampaolo Benevento, D. Bertacca, C. Bonvin, et al.
Nature Astronomy, Published online: 25 September 2026; doi:10.1038/s41550-026-02984-6 Volatile depletion in rocky planets records their formation history. Earth and Mars grew through different hybrid pathways of pebble and planetesimal accretion, providing a new way to interpret the diversity of rocky planets beyond the Solar System.
Nature Astronomy, Published online: 24 September 2026; doi:10.1038/s41550-026-02975-7 LHAASO observations reveal ultrahigh-energy γ-rays from nearby giant molecular clouds, identifying these clouds as natural laboratories for mapping cosmic rays across the Milky Way.
We present a GPU-accelerated, PyTorch tensor-based simulation framework designed to generate high-fidelity galaxy–galaxy strong lensing (GGSL) images. By integrating synthetic spectral energy distributions (SEDs), the pipeline accurately models the redshift-dependent photometric properties of lens and source galaxies, ensuring physical consistency across multi-band observations. The framework incorporates key observ…
Nature Astronomy, Published online: 24 September 2026; doi:10.1038/s41550-026-02988-2 Deep JWST spectra of three galaxies seen within the Universe’s first 700 million years allow the detection of blueshifted, chemically enriched gas, providing evidence that baryon cycling began very early.
The effects of weak gravitational lensing induced by clusters of galaxies makes it possible to constrain their dark matter distribution. In general mass estimates from weak lensing are made by compressing the two-dimensional shear-field into one-dimension. In this work we build a forward model of the two-dimensional reduced-shear field around a galaxy cluster, including the non-Gaussian correlated large-scale struct…