2 sujets /DAp/LCEG

Dernière mise à jour : 02-12-2021


 

Measuring the growth of massive structures in the distant Universe with deep multi-wavelength surveys

SL-DRF-22-0311

Research field : Astrophysics
Location :

Direction d’Astrophysique (DAP)

Laboratoire de Cosmologie et d’Evolution des Galaxies (LCEG)

Saclay

Contact :

Emanuele DADDI

Starting date : 01-10-2021

Contact :

Emanuele DADDI
CEA - DRF/IRFU/DAP/LCEG


Thesis supervisor :

Emanuele DADDI
CEA - DRF/IRFU/DAP/LCEG


A growing convergence of research lines point to the first massive structures, like groups and clusters, assembling in the distant Universe as rosetta-stones to try to unveil important unsolved questions in galaxy and structures formation and evolution. This includes understanding the physical processes by which galaxies are fuelled by gas (which allows them to form their stars), by which galaxies change their structures, the role played by galaxy mergers, the feedback with their internal growing black holes, and interactions and the paths through which they eventually stop forming stars.



We propose a PhD project in which the student will participate to this research within a large international consortium that is leading large observational program of distant groups and clusters. Primarily the PhD student will be involved in using data from a recently awarded large program with the NOEMA interferometer that will use 159 hours of observations to discovery (confirm) and study 40 groups and clusters at 2


This thesis will potentially provide a solid formation for the student in many aspects of observational cosmology, from observations at one of the best ground-based telescopes to data analysis and interpretation all the way possibly to modeling, based also on the interests of the students and on results.
Understanding the evolution of galaxies with the James Webb Space Telescope

SL-DRF-22-0365

Research field : Astrophysics
Location :

Direction d’Astrophysique (DAP)

Laboratoire de Cosmologie et d’Evolution des Galaxies (LCEG)

Saclay

Contact :

Benjamin MAGNELLI

David ELBAZ

Starting date : 01-09-2022

Contact :

Benjamin MAGNELLI
CEA - DRF/IRFU

0169086825

Thesis supervisor :

David ELBAZ
CEA - DRF/IRFU

0169085439

The James Webb Space Telescope (JWST) will revolutionize our understanding of the evolution of galaxies in the so-called "cosmic noon" era. With its unparalleled angular resolution in the near- and mid-infrared window, it will measure the distributions of stars and dust-obscured star formation on the kpc scale, and reveal the presence of active dust-obscured supermassive black holes at their centers.

In the scenario so far favored to explain the evolution of galaxies and, in particular, the morphological transformation of spirals into ellipticals, it is the mergers of galaxies that destroy the disks and generate the spheroids. However, recent observations by our team have revealed the presence of compact star-forming nuclei in distant galaxies, supporting an alternative scenario in which they were built in situ, slowly and not abruptly.

This thesis will aim to distinguish these two scenarios of galaxy formation and morphological transformation by combining JWST/PRIMER/NIRCam images with HST/CANDELS/ACS images. Our team will have access to two major JWST cosmological programs, CEERS (PI. S.Finkelstein) and PRIMER (PI. J.Dunlop) whose data should arrive as early as June 2022 (or at the latest Dec.2022). We will perform a spatially resolved analysis of the spectral energy distribution of about 1200 galaxies which will allow, in particular, to determine their distribution of stars and star formation, decisive information to understand their origin and evolution.

 

Retour en haut