A. Boucaud
A5008126526- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Advanced Vision and Imaging
- Remote Sensing in Agriculture
- Statistical and numerical algorithms
- CCD and CMOS Imaging Sensors
- Gaussian Processes and Bayesian Inference
- Particle physics theoretical and experimental studies
- History and Developments in Astronomy
- Computational Physics and Python Applications
- Astrophysics and Star Formation Studies
- Calibration and Measurement Techniques
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Impact of Light on Environment and Health
- Genomic variations and chromosomal abnormalities
- Radio Astronomy Observations and Technology
- Speech Recognition and Synthesis
- Scientific Research and Discoveries
Centre National de la Recherche Scientifique
2016-2025
Laboratoire AstroParticule et Cosmologie
2013-2025
Université Paris Cité
2019-2025
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2023
Université de Tours
2023
Laboratoire Hubert Curien
2022
Université Paris-Saclay
2016-2021
Inria Saclay - Île de France
2021
Sorbonne Paris Cité
2019-2020
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2019-2020
The Euclid space telescope will measure the shapes and redshifts of galaxies to reconstruct expansion history Universe growth cosmic structures. Estimation expected performance experiment, in terms predicted constraints on cosmological parameters, has so far relied different methodologies numerical implementations, developed for observational probes their combination. In this paper we present validated forecasts, that combine both theoretical expertise probes. This is presented provide...
Aims. We present the first public release of photometric redshifts, galaxy rest frame properties and associated magnification values in cluster parallel pointings two Frontier Fields, Abell-2744 MACS-J0416. The released catalogues aim to provide a reference for future investigations extragalactic populations these legacy fields: from lensed high-redshift galaxies members themselves.
Context. Open clusters (OCs) are popular tracers of the structure and evolutionary history Galactic disc. The OC population is often considered to be complete within 1.8 kpc Sun. recent Gaia Data Release 2 (DR2) allows latter claim challenged. Aims. We perform a systematic search for new OCs in direction Perseus using precise accurate astrometry from DR2. Methods. implemented coarse-to-fine method. First, we exploited spatial proximity fast density-aware partitioning sky via k -d tree domain...
Context. The Frontier Fields survey is a pioneering observational program aimed at collecting photometric data, both from space (Hubble Space Telescope and Spitzer Telescope) ground-based facilities (VLT Hawk-I), for six deep fields pointing clusters of galaxies nearby parallel fields, in wide range passbands. analysis these data natural outcome the Astrodeep project, an EU collaboration developing methods tools extragalactic photometry creating valuable public catalogues.
MRI has been extensively used to identify anatomical and functional differences in Autism Spectrum Disorder (ASD). Yet, many of these findings have proven difficult replicate because studies rely on small cohorts are built complex, undisclosed, analytic choices. We conducted an international challenge predict ASD diagnosis from data, where we provided preprocessed data > 2,000 individuals. Evaluation the predictions was rigorously blinded. 146 challengers submitted prediction algorithms,...
We present jax-cosmo, a library for automatically differentiable cosmological theory calculations. It uses the JAX library, which has created new coding ecosystem, especially in probabilistic programming. As well as batch acceleration, just-in-time compilation, and automatic optimization of code different hardware modalities (CPU, GPU, TPU), exposes an differentiation (autodiff) mechanism. Thanks to autodiff, jax-cosmo gives access derivatives likelihoods with respect any their parameters,...
Fink is a broker designed to enable science with large time-domain alert streams such as the one from upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). It exhibits traditional astronomy features automatised ingestion, annotation, selection redistribution promising alerts for transient science. also go beyond by providing real-time classification which continuously improved using state-of-the-art Deep Learning Adaptive techniques. These evolving added values will more...
ABSTRACT The new generation of deep photometric surveys requires unprecedentedly precise shape and photometry measurements billions galaxies to achieve their main science goals. At such depths, one major limiting factor is the blending due line-of-sight projection, with an expected fraction blended up 50 per cent. This proof-of-concept work explores for first time use neural networks estimate pairs in space-based monochrome images similar ones that will be delivered by Euclidspace telescope...
We present an open source Python library for simulating overlapping (i.e., blended) images of galaxies and performing self-consistent comparisons detection deblending algorithms based on a suite metrics. The package, named Blending Toolkit (BTK), serves as modular, flexible, easy-to-install, simple-to-use interface exploring analyzing systematic effects related to blended in cosmological surveys such the Vera Rubin Observatory Legacy Survey Space Time (LSST). BTK has three main components:...
Traditionally, weak lensing cosmological surveys have been analyzed using summary statistics that were either motivated by their analytically tractable likelihoods (e.g., power spectrum) or ability to access some higher-order information peak counts), but at the cost of requiring a simulation-based inference approach. In both cases, even if can be very informative, they are not designed nor guaranteed statistically sufficient (i.e., capture all content data). With rise deep learning,...
Context. The European Space Agency’s Euclid mission is one of a raft forthcoming large-scale cosmology surveys that will map the structure in Universe with unprecedented precision. collect vast amount data be processed and analysed by ’s Science Ground Segment (SGS). development validation SGS pipeline requires state-of-the-art simulations high level complexity accuracy include subtle instrumental features not accounted for previously as well faster algorithms production expected products....
Weak lensing, which is the deflection of light by matter along line sight, has proven to be an efficient method for constraining models structure formation and reveal nature dark energy. So far, most weak-lensing studies have focused on shear field that can measured directly from ellipticity background galaxies. However, within context forthcoming full-sky surveys such as Euclid, convergence maps (mass maps) offer important advantage over fields in terms cosmological exploitation. While it...
The accuracy of photometric redshifts (photo-zs) particularly affects the results analyses galaxy clustering with photometrically-selected galaxies (GCph) and weak lensing. In next decade, space missions like Euclid will collect measurements for millions galaxies. These data should be complemented upcoming ground-based observations to derive precise accurate photo-zs. this paper, we explore how tomographic redshift binning depth affect cosmological constraints expected from Euclid. We focus...
We present a machine learning framework to simulate realistic galaxies for the Euclid Survey. The proposed method combines control on galaxy shape parameters offered by analytic models with surface brightness distributions learned from real Hubble Space Telescope observations deep generative models. field of $0.4\,\rm{deg}^2$ as it will be seen visible imager VIS and show that structural are recovered similar accuracy pure S\'ersic profiles. Based these simulations, we estimate Wide Survey...
The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering over an unprecedented area 15 000 square degrees with high spatial resolution. In order to understand the capabilities measuring morphologies from Euclid-detected galaxies and help implement measurements in pipeline, we have conducted Morphology Challenge, which present two papers. While companion paper Merlin et al. focuses on analysis photometry, this assesses accuracy parametric...
The data from the Euclid mission will enable measurement of photometric redshifts, angular positions, and weak lensing shapes for over a billion galaxies. This large dataset allow cosmological analyses using clustering galaxies cosmic shear. cross-correlation (XC) between these probes can tighten constraints it is therefore important to quantify their impact Euclid. In this study we carefully XC not only on final parameter different models, but also nuisance parameters. particular, aim at...
The analysis of weak gravitational lensing in wide-field imaging surveys is considered to be a major cosmological probe dark energy. Our capacity constrain the energy equation state relies on accurate knowledge galaxy mean redshift $\langle z \rangle$. We investigate possibility measuring \rangle$ with an accuracy better than $0.002\,(1+z)$, ten tomographic bins spanning interval $0.299.8\%$. zPDF approach could also successful if we debias using spectroscopic training sample. This requires...
We present jax-cosmo, a library for automatically differentiable cosmological theory calculations. It uses the JAX library, which has created new coding ecosystem, especially in probabilistic programming. As well as batch acceleration, just-in-time compilation, and automatic optimization of code different hardware modalities (CPU, GPU, TPU), exposes an differentiation (autodiff) mechanism. Thanks to autodiff, jax-cosmo gives access derivatives likelihoods with respect any their parameters,...
Astrophysical images issued from different instruments and/or spectral bands often require to be processed together, either for fitting or comparison purposes. However each image is affected by an instrumental response, also known as point-spread function (PSF), that depends on the characteristics of instrument well wavelength and observing strategy. Given knowledge PSF in band, a straightforward way processing homogenise them all target using convolution kernels, so they appear if had been...
Upcoming surveys will map the growth of large-scale structure with unprecented precision, improving our understanding dark sector Universe. Unfortunately, much cosmological information is encoded by small scales, where clustering matter and effects astrophysical feedback processes are not fully understood. This can bias estimates parameters, which we study here for a joint analysis mock Euclid cosmic shear Planck microwave background data. We use different implementations modelling signal on...