L. Pecoraro | Searcharxiv

arXiv2026

A New Perspective on Galactic Evolution: Studying the Outskirts of the Abell S1063 Galaxy Cluster

Galaxy physical properties are influenced by their environments, but the processes responsible for mass and environmental quenching and structural transformations remain debated. Galaxy clusters are ideal laboratories for investigating galaxy formation and evolution, offering a full range of galaxy properties and environments. Observations of large-scale structures, particularly filaments in cluster outskirts ($r \sim5r_{200}$), are currently constrained to the low-redshift Universe. To explore galaxy evolution at intermediate redshifts, deep photometric data, ideally combined with spectroscopic redshifts, are essential. Abell S1063 cluster ($z$ = 0.346) is observed within the Galaxy Assembly as a function of the Mass and Environment program with the VLT Survey Telescope (VST-GAME) combined VISTA Public Survey program Galaxy Cluster At Vircam. We investigate galaxy evolution across a wide range of stellar masses and environments. We release a multiwavelength photometric catalog with photometric redshifts for 64394 sources in $1x1 deg^2$. The analysis of overdensity regions provides insights for future studies on galaxy properties in cluster outskirts. The dataset is obtained through deep ($r<$24.65 mag) and wide optical ($u$, $g$, $r$, $i$, VST) and near-infrared ($Y$, $J$, $K_s$, VISTA) observations. The photometric catalog includes all detected sources, excluding nearby or overlapping objects, saturated stars, and image artifacts. The multiwavelength catalog enabled photometric redshift estimates and identification of cluster members. The density field allowed comparison of galaxy properties, colors, and masses across environments. We detect a very dense structure near the cluster center, and with such a large field of view, we find another dense region to the north-west, in the opposite direction to the cluster elongation. Filaments connecting the regions are also visible.

astro-ph.GA↗

arXiv2025

Is there a tilt in the fundamental (hyper)plane?

We investigate the fundamental plane (FP) of selected early-type (ETG) member galaxies of the galaxy cluster PLCK G287.0+32.9 ($ z_c = 0.3833 $), exploring also four-dimensional hyperplane extensions. We measure ETGs structural parameters and photometry from Hubble Space Telescope (HST) observations. We use high-quality spectroscopic data from the Multi Unit Spectroscopic Explorer (MUSE) to measure the galaxy central stellar velocity dispersions and stellar population properties. With this data, we construct the FP through a robust fitting procedure and analyze its tilt and scatter. We then introduce two hyperplane extensions, one including the stellar mass ($M^\star$-HP) and another including the stellar over total mass fraction ($f_{\mathrm{e}}^\star$-HP), and compare their coefficients and scatter to those of the FP. The FP of PLCK G287.0+32.9 is found to have best-fit parameter values consistent with those in the literature ($\alpha = 1.2 \pm 0.1$ and $\beta = -0.75 \pm 0.05$), with a scatter of $0.09$ dex. The ($f_{\mathrm{e}}^\star$-HP) shows no tilt compared to the theoretical plane ($\alpha = 2.1 \pm 0.2$ and $\beta = -1.12 \pm 0.07$), with a scatter of $0.042$ dex, and the ($M^\star$-HP) reveals an even tighter relation, with a scatter of only $0.023$. Our findings support the idea that the FP is a lower-dimensional projection of a more complex hyperplane and confirm that the variations in the dark matter content contribute significantly to the tilt of the FP. Future studies incorporating larger samples of galaxies and additional physical parameters may further refine our understanding of the FP and its higher-dimensional extensions.

astro-ph.GA↗