M. Melchior

Euclid: Quick Data Release (Q1) -- Exploring the detailed visual morphology of galaxies in clusters

P. Mas-Buitrago, S. Kruk, D. O'Ryan +167

Galaxy clusters provide unique laboratories for studying environmental effects on galaxy evolution. The morphology--density ( $T$ -- $Σ$ ) and morphology--cluster-centric radius ( $T$ --…

Euclid: Calibrating distances from surface brightness fluctuations with Early Release Observations of the Fornax cluster

R. Habas, M. Cantiello, G. Riccio +169

Surface brightness fluctuations (SBF), the pixel-to-pixel variations in flux that arise from the statistical distribution of stars in galaxy images, provide a powerful tool to meas…

Euclid: A UV-faint quasar in a highly luminous star-forming host galaxy at $z \approx 7.7$

S. Belladitta, R. Decarli, E. Bañados +180

Constraining the co-evolution of supermassive black holes and their host galaxies in the first billion years after the Big Bang is essential for understanding the formation of the…

Euclid: Disky titans - surprisingly high star formation activity and gas content in two brightest group galaxies at z~0.75

F. Gentile, E. Daddi, D. Elbaz +166

We present the discovery of two disky titans in the first data release of the Euclid satellite. These sources are massive (M>10^11 Msun) star-forming (SFR~20 Msun/yr) discs located…

Euclid Quick Data Release (Q1). AgileLens: A scalable CNN-based pipeline for strong gravitational lens identification

Euclid Collaboration, X. Xu, R. Chen +308

We present an end-to-end, iterative pipeline for efficient identification of strong galaxy--galaxy lensing systems, applied to the Euclid Q1 imaging data. Starting from VIS catalog…

Euclid preparation. Far-infrared predictions for Euclid galaxy catalogues: cluster, protocluster, and field

Euclid Collaboration, A. Parmar, D. L. Clements +297

The MAMBO mock galaxy catalogue, based on the Millennium Simulation with empirically assigned galaxy properties, provides predictions of FIR fluxes and physical parameters of Eucli…

Euclid: Early Release Observations -- The extended stellar component of the IC10 dwarf galaxy

F. Annibali, A. M. N. Ferguson, P. M. Sanchez-Alarcon +175

We present a detailed analysis of the old, extended stellar component of the Local Group dwarf galaxy IC 10 using deep resolved-star photometry in the VIS and NISP bands of the Euc…

Euclid Quick Data Release (Q1): Euclid spectroscopy of quasars. 1. Identification and redshift determination of 3500 bright quasars

Euclid Collaboration, Y. Fu, R. Bouwens +354

The slitless spectroscopy mode of the NISP onboard Euclid has enabled efficient spectroscopy of objects within a large FoV. We present a large and homogeneous sample of bright quas…

Euclid preparation: LXXXI. The impact of nonparametric star formation histories on spatially resolved galaxy property estimation using synthetic Euclid images

Euclid Collaboration, A. Nersesian, Abdurro'uf +283

We analyzed the spatially resolved and global star formation histories (SFHs) for a sample of 25 TNG50-SKIRT Atlas galaxies to assess the feasibility of reconstructing accurate SFH…

Euclid Quick Data Release (Q1): Identification of massive galaxy candidates at the end of the Epoch of Reionisation

Euclid Collaboration, R. Navarro-Carrera, K. I. Caputi +295

Probing the presence and properties of massive galaxies at high redshift is one of the most critical tests for galaxy formation models. In this work, we search for galaxies with st…

Euclid Quick Data Release (Q1). Spectroscopic unveiling of highly ionised lines at z = 2.48-3.88

Euclid Collaboration, D. Vergani, S. Quai +316

This study explores a rare population of sources in a currently uncharted region of spectroscopic redshift space in the Euclid Quick Data Release (Q1), and is intended potentially…

Euclid Quick Data Release (Q1). The average far-infrared properties of Euclid-selected star-forming galaxies

Euclid Collaboration, R. Hill, A. Abghari +302

The first Euclid Quick Data Release contains millions of galaxies with excellent optical and near-infrared (IR) coverage. To complement this dataset, we investigate the average far…

Euclid Quick Data Release (Q1). Quenching precedes bulge formation in dense environments but follows it in the field

Euclid Collaboration, F. Gentile, E. Daddi +321

(Abridged) The bimodality between star-forming discs and quiescent spheroids requires the existence of two main processes: the galaxy quenching and the morphological transformation…

Euclid: Discovery of bright $z ≃ 7$ Lyman-break galaxies in UltraVISTA and Euclid COSMOS

R. G. Varadaraj, R. A. A. Bowler, M. J. Jarvis +163

We present a search for $z ≃ 7$ Lyman-break galaxies using the $1.72 deg^{2}$ near-infrared UltraVISTA survey in the COSMOS field, reaching $5 σ$ depths in $Y$ of 26.2. W…

astro-ph.GA2025★ 1 cited

Euclid: A machine-learning search for dual and lensed AGN at sub-arcsec separations

L. Ulivi, F. Mannucci, M. Scialpi +189

Cosmological models of hierarchical structure formation predict the existence of a widespread population of dual accreting supermassive black holes (SMBHs) on kpc-scale separations…

Euclid preparation. Predicting star-forming galaxy scaling relations with the spectral stacking code SpectraPyle

Euclid Collaboration, S. Quai, L. Pozzetti +309

We introduce SpectraPyle, a versatile spectral stacking pipeline developed for the Euclid mission's NISP spectroscopic surveys, aimed at extracting faint emission lines and spectra…

Euclid: Early Release Observations -- The star cluster systems of the Local Group dwarf galaxies IC 10 and NGC 6822

J. M. Howell, A. M. N. Ferguson, S. S. Larsen +149

Star clusters are valuable indicators of galaxy evolution, offering insights into the buildup of stellar populations across cosmic time. Understanding intrinsic star cluster popula…

Euclid preparation. Estimating galaxy physical properties using CatBoost chained regressors with attention

Euclid Collaboration, A. Humphrey, P. A. C. Cunha +232

Euclid will image ~14000 deg^2 of the extragalactic sky at visible and NIR wavelengths, providing a dataset of unprecedented size and richness that will facilitate a multitude of s…

astro-ph.GA2025★ 7 cited

Euclid preparation LXX. Forecasting detection limits for intracluster light in the Euclid Wide Survey

Euclid Collaboration, C. Bellhouse, J. B. Golden-Marx +292

The intracluster light (ICL) permeating galaxy clusters is a tracer of the cluster's assembly history, and potentially a tracer of their dark matter structure. In this work we expl…

Euclid: Quick Data Release (Q1) -- A census of dwarf galaxies across a range of distances and environments

F. R. Marleau, R. Habas, D. Carollo +204

The Euclid Q1 fields were selected for calibration purposes in cosmology and are therefore relatively devoid of nearby galaxies. However, this is precisely what makes them interest…

Euclid Quick Data Release (Q1). Galaxy shapes and alignments in the cosmic web

Euclid Collaboration, C. Laigle, C. Gouin +341

Galaxy morphologies and shape orientations are expected to correlate with their large-scale environment, since they grow by accreting matter from the cosmic web and are subject to…

Euclid Quick Data Release (Q1). The Strong Lensing Discovery Engine E -- Ensemble classification of strong gravitational lenses: lessons for Data Release 1

Euclid Collaboration, P. Holloway, A. Verma +343

The Euclid Wide Survey (EWS) is expected to identify of order $100000$ galaxy-galaxy strong lenses across $14000$ deg $^{2}$ . The Euclid Quick Data Release (Q1) of $63.1$ deg $^{2}$ Eu…

astro-ph.GA2025★ 3 cited

Euclid Quick Data Release (Q1) The Strong Lensing Discovery Engine B -- Early strong lens candidates from visual inspection of high velocity dispersion galaxies

Euclid Collaboration, K. Rojas, T. E. Collett +336

We present a search for strong gravitational lenses in Euclid imaging with high stellar velocity dispersion ( $σ_{ν} > 180$ km/s) reported by SDSS and DESI. We performed expert visual…