Publications by Gianluca Castignani

Euclid preparation XXXVII. Galaxy colour selections with Euclid and ground photometry for cluster weak-lensing analyses

Matthias Wiesmann, Georges Meylan, Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Yi Wang

Aims. We derived galaxy colour selections from Euclid and ground-based photometry, aiming to accurately define background galaxy samples in cluster weak-lensing analyses. These selections have been implemented in the Euclid data analysis pipelines for gala ...

Edp Sciences S A2024

XXXIV. The effect of linear redshift-space distortions in photometric galaxy clustering and its cross-correlation with cosmic shear

Slobodan Ilic, Malte Tewes, Georges Meylan, Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Alessandro Pezzotta, Gianluca Castignani, Marcello Farina, Yi Wang

Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Univ ...

Edp Sciences S A2024

Euclid preparation XXXVI. Modelling the weak lensing angular power spectrum

Georges Meylan, Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

This work considers which higher order modeling e ffects on the cosmic shear angular power spectra must be taken into account for Euclid. We identified the relevant terms and quantified their individual and cumulative impact on the cosmological parameter i ...

Edp Sciences S A2024

Euclid preparation XXII. Selection of quiescent galaxies from mock photometry using machine learning

Georges Meylan, Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

The Euclid Space Telescope will provide deep imaging at optical and near-infrared wavelengths, along with slitless near-infrared spectroscopy, across similar to 15 000deg(2) of the sky. Euclid is expected to detect similar to 12 billion astronomical source ...

EDP SCIENCES S A2023

Euclid preparation XXX. Performance assessment of the NISP red grism through spectroscopic simulations for the wide and deep surveys

Georges Meylan, Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Michaela Hirschmann, Yi Wang

This work focusses on the pilot run of a simulation campaign aimed at investigating the spectroscopic capabilities of the Euclid NearInfrared Spectrometer and Photometer (NISP), in terms of continuum and emission line detection in the context of galaxy evo ...

EDP SCIENCES S A2023

Euclid preparation: XXVIII. Forecasts for ten different higher-order weak lensing statistics

Frédéric Courbin, Fabio Finelli, Richard Massey, Maurizio Martinelli, Jean-Luc Starck, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

Recent cosmic shear studies have shown that higher-order statistics (HOS) developed by independent teams now outperform standard two-point estimators in terms of statistical precision thanks to their sensitivity to the non-Gaussian features of large-scale ...

EDP SCIENCES S A2023

Euclid preparation XXIV. Calibration of the halo mass function in λ(ν)CDM cosmologies

Slobodan Ilic, Georges Meylan, Frédéric Courbin, Fabio Finelli, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

Euclid's photometric galaxy cluster survey has the potential to be a very competitive cosmological probe. The main cosmological probe with observations of clusters is their number count, within which the halo mass function (HMF) is a key theoretical quanti ...

EDP SCIENCES S A2023

Euclid preparation - XXIII. Derivation of galaxy physical properties with deep machine learning using mock fluxes and H-band images

Robin Humphry-Baker, Georges Meylan, Frédéric Courbin, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

Next-generation telescopes, like Euclid, Rubin/LSST, and Roman, will open new windows on the Universe, allowing us to infer physical properties for tens of millions of galaxies. Machine-learning methods are increasingly becoming the most efficient tools to ...

OXFORD UNIV PRESS2023

Euclid preparation XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies

Slobodan Ilic, Georges Meylan, Frédéric Courbin, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Yi Wang

The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morpholo ...

2023

Euclid preparation XXI. Intermediate-redshift contaminants in the search for z > 6 galaxies within the Euclid Deep Survey

Georges Meylan, Frédéric Courbin, Hakim Atek, Richard Massey, Maurizio Martinelli, Jean-Luc Starck, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

Context. The Euclid mission is expected to discover thousands of z > 6 galaxies in three deep fields, which together will cover a similar to 50 deg(2) area. However, the limited number of Euclid bands (four) and the low availability of ancillary data could ...

EDP SCIENCES S A2022

Virgo Filaments. II. Catalog and First Results on the Effect of Filaments on Galaxy Properties

Pascale Jablonka, Gianluca Castignani

Virgo is the nearest galaxy cluster; it is thus ideal for studies of galaxy evolution in dense environments in the local universe. It is embedded in a complex filamentary network of galaxies and groups, which represents the skeleton of the large-scale Lani ...

IOP Publishing Ltd2022

Euclid preparation XVI. Exploring the ultra-low surface brightness Universe with Euclid/VIS

Georges Meylan, Gianluca Castignani

Context. While Euclid is an ESA mission specifically designed to investigate the nature of dark energy and dark matter, the planned unprecedented combination of survey area (similar to 15000 deg(2)), spatial resolution, low sky-background, and depth also m ...

EDP SCIENCES S A2022

SEEDisCS: I. Molecular gas in galaxy clusters and their large-scale structure: The case of CL1411.1-1148 at z similar to 0.5

Pascale Jablonka, Damien Louis Alexandre Spérone-Longin, Gianluca Castignani

We investigate how the galaxy reservoirs of molecular gas fuelling star formation are transformed while the host galaxies infall onto galaxy cluster cores. As part of the Spatially Extended ESO Distant Cluster Survey (SEEDisCS), we present CO(3-2) observat ...

EDP SCIENCES S A2021

Virgo filaments I. Processing of gas in cosmological filaments around the Virgo cluster

Pascale Jablonka, Gianluca Castignani

It is now well established that galaxies have different morphologies, gas contents, and star formation rates (SFR) in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies appear to be pr ...

EDP SCIENCES S A2021

Molecular gas in galaxy clusters and their large-scale structure: The case of CL1411.1-1148 at z similar to 0.5 (vol 647, A156, 2021)

Pascale Jablonka, Damien Louis Alexandre Spérone-Longin, Gianluca Castignani

EDP SCIENCES S A2021

Euclid preparation: IX. EuclidEmulator2-power spectrum emulation with massive neutrinos and self-consistent dark energy perturbations

Georges Meylan, Fabio Finelli, Richard Massey, Gianluca Castignani, Yi Wang

We present a new, updated version of the EuclidEmulator (called EuclidEmulator2), a fast and accurate predictor for the nonlinear correction of the matter power spectrum. 2 per cent level accurate emulation is now supported in the eight-dimensional paramet ...

OXFORD UNIV PRESS2021

Euclid Preparation. XIV. The Complete Calibration of the Color-Redshift Relation (C3R2) Survey: Data Release 3

Georges Meylan, Gianluca Castignani

The Complete Calibration of the Color-Redshift Relation (C3R2) survey is obtaining spectroscopic redshifts in order to map the relation between galaxy color and redshift to a depth of i similar to 24.5 (AB). The primary goal is to enable sufficiently accur ...

IOP PUBLISHING LTD2021

Euclid preparation XII. Optimizing the photometric sample of the Euclid survey for galaxy clustering and galaxy-galaxy lensing analyses

Georges Meylan, Gianluca Castignani

Photometric redshifts (photo-zs) are one of the main ingredients in the analysis of cosmological probes. Their accuracy particularly affects the results of the analyses of galaxy clustering with photometrically selected galaxies (GC(ph)) and weak lensing. ...

EDP SCIENCES S A2021

Euclid preparation: XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography

Fabio Finelli, Richard Massey, Gianluca Castignani, Yi Wang

The analysis of weak gravitational lensing in wide-field imaging surveys is considered to be a major cosmological probe of dark energy. Our capacity to constrain the dark energy equation of state relies on an accurate knowledge of the galaxy mean redshift ...

2021

Molecular gas and star formation activity in luminous infrared galaxies in clusters at intermediate redshifts

Pascale Jablonka, Damien Louis Alexandre Spérone-Longin, Mathilde Jauzac, Gianluca Castignani

We investigate the role of dense megaparsec-scale environments in processing molecular gas of cluster galaxies as they fall into the cluster cores. We selected a sample of similar to 20 luminous infrared galaxies (LIRGs) belonging to intermediate-redshift ...

EDP SCIENCES S A2020