The LSST consortium is made of several science collaborations, including DESC for which the French community is particularly active. However a number of French researchers especially from INSU also have an important contribution in the Galaxies Science Collaboration. I will review these activities, with an emphasis on the LSB science, and sky background subtraction which is crucial to...
The standard model of cosmology is founded on the cosmological principle which
is the hypothesis of large-scale homogeneity and isotropy of the Universe.This hypothesis imposes that the rest frame of distant galaxies coincides with the rest frame of CMB. I will present some of the results we have obtained using the latest catalogues of radio galaxies and quasars which show that the...
The Rubin LSST and the Euclid survey will each deliver groundbreaking astronomical datasets over this decade in the optical and near-infrared. Both surveys will map thousands of square degrees of sky from the ground and space respectively, with
an overlap area of approximately 9000 square degrees at high galactic latitudes. The combination of Euclid’s high spatial resolution imaging in the...
We will review the status of Fink, the latest scientific results, and the plans for the Rubin commissioning (and beyond).
The recent increase in volume and complexity of available astronomical data has led to a wide use of supervised machine learning techniques. Active learning strategies have been proposed as an alternative to optimize the distribution of scarce labeling resources. However, due to the specific conditions in which labels can be acquired, fundamental assumptions, such as sample representativeness...
Gamma-Ray Bursts (GRB) are among the most energetic phenomena in the Universe. The interaction of their blast wave with the Interstellar Medium produces an afterglow that can be observed from a larger angle, in a wide range of the electromagnetic spectrum and during more time than the prompt emission. Viewed off-axis, this emission has a negligible gamma-ray flux and is hence called ”GRB...
I will present an overview of the new ZTF calibration pipeline developped at in2p3, giving an update on different steps: bias corrections, flatfielding, star-flats, photometric calibration (ubercal), and scene modeling photometry.
Je présenterais des résultats préliminaires de l'échantillon "volume limited" de SNeIa de ZTF : distributions en stretch, couleur,... ainsi que les dépendances des magnitudes des SNe à ces mêmes paramètres.
On développe un code de forward modelling dans le but d'extraire une valeur du taux de croissance des structures fsigma8. Je vais présenter le Direct Acyclic Graph (DAG) de ce code.
We explore machine learning networks to detect galaxy clusters in optical images. We present first result on the SDSS. Our networks are very efficient to reproduce the redmapper cluster catalog.
A standard choice for cosmological cluster analyses is a Poissonian likelihood; however such a likelihood neglects the effects of sample variance from density fluctuations across the survey volume. To date this assumption has been justified but to make the most of the future data such as that of the Rubin Observatory and the Euclid satellite, improvements to the cluster likelihood must be...
The DESC Bayesian analysis pipeline project recently created aims to coordinate and promote the development of a standardized open source Bayesian Pipeline which ultimately could connect pixels to cosmology. Two subprojects has emerged: one concerning "Pixels to shear" starting from simulated/DC2 images to infer posterior weak lensing shear and convergence fields on the sky (eg. BLISS,...),...
