STAGE Weak gravitational lensing: shear measurement and calibration in CFIS data

Date de mise à jour de l’offre

CEA - Paris Saclay :

CEA - Paris Saclay Institut de Recherche sur les lois Fondamentales de l'Univers Département d'Astrophysique

Description de la mission

http://www.cosmostat.org/jobs



Nature du travail demandé : Simulations numériques,

Traitement de données



One of the most important techniques for cosmological analyses in modern surveys is weak gravitational lensing, which allows us to measure the total mass distribution (including dark matter) of the Universe from galaxy images. The quality of weak lensing measurements in observations depends on the accuracy of the ellipticity estimation of the galaxy images and its correct calibration.



This internship will consist on applying different calibration approaches on the images coming from the Canada-France Imaging Survey (http://cfht.hawaii.edu/en/science/LargePrograms/LP_17_19/index.php).

With 5,000 deg2 sky coverage this will be one of the largest weak-lensing surveys ever conducted. On one side, the student will apply the so-called metacalibration approach for CFIS data to produce a weak lensing catalogue which is independent on simulations. On the other side, the student will use a bias calibration based on machine learning techniques on CFIS image simulations that will be applied to the real data. We will compare the performance and consistencies of both methods and will also study the impact of this calibration on different statistics and cosmological analyses.

Profil recherché

Pré-requis : connaissances en astrophysique, cosmologie, traitement d'images astronomiques sera utile

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    CEA - Paris Saclay
  • Secteur d’activité de la structure
    Enseignement - Formation - Recherche
  • Effectif de la structure
    Plus de 250 salariés
  • Type de stage ou contrat
    Stage pour lycéens et étudiants en formation initiale
  • Date prévisionnelle de démarrage
  • Durée du stage ou contrat
    Plus de 4 mois et jusqu'à 6 mois
  • Le stage est-il rémunéré ?
    Oui
  • Niveau de qualification requis

    Bac + 4/5 et +
  • Lieu du stage
    RTE N306 RD 36
    91190 GIF SUR YVETTE
  • Accès et transports
    Bus