Euclid と重力レンズ

A&A

論文Nature Astronomy·2026/09/29

Growth of aromatic hydrocarbon dust particles in the extremely metal-poor galaxy Sextans A

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.

A&A

論文Nature Astronomy·2026/09/29

First-star imprints in a metal-poor galaxy overdensity near the end of reionization

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.

OA

プレプリントOpenAlex·2026/09/24

Joint Model-independent Constraints on the Post-Newtonian Parameter and Cosmic Curvature from Galaxy-scale Strong Lensing, SNe Ia, BAO, and Cosmic Chronometers

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…

A&A

論文Nature Astronomy·2026/09/28

Persistent primordial signature in present-day galaxies

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.

OA

論文OpenAlex·2026/09/25

First Application of Weak Lensing Peak Steepness Statistics to HSC Year 1 Data: Effectively Probing Halo Density Profiles

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…

A&A

論文Nature Astronomy·2026/09/28

Beyond Hubble: revisiting the Hubble sequence across cosmic time

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.

OA

論文OpenAlex·2026/09/24

Probing the Baryonic Feedback Effect with CSST Weak Lensing and Future Fast Radio Burst Measurements

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…

A&A

論文Astronomy & Astrophysics·2026/09/15

Observation-driven simulations of strong-lensing galaxy clusters

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…

A&A

論文Nature Astronomy·2026/09/25

Λ CDM in a courtroom

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.

A&A

論文Astronomy & Astrophysics·2026/09/23

Euclid preparation. CXIV. Review of forecast constraints on dark energy and modified gravity

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…

A&A

論文Nature Astronomy·2026/09/25

Volatile depletion in rocky planets as a chemical fingerprint of hybrid accretion

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.

A&A

論文Nature Astronomy·2026/09/24

LHAASO detection of ultrahigh-energy γ-ray emission towards giant molecular clouds

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.

OA

論文OpenAlex·2026/09/23

Galaxy–galaxy strong lensing simulation with GPU acceleration across surveys and multi-bands

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…

A&A

論文Nature Astronomy·2026/09/24

Early metal-enriched baryon cycling before the midpoint of cosmic reionization

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.

OA

プレプリントOpenAlex·2026/09/21

Two-dimensional weak lensing shear for cluster mass, concentration, ellipticity and miscentering estimation

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…