Thesis

Dawn of MOONS and EUCLID: The high redshift Universe with the largest emission line surveys

• Call:

  IDPASC Portugal - PHD Programme 2015

• Academic Year:

  2015 / 2016

• Domains:

  Cosmology | Astrophysics

• Supervisor:

  David Sobral

• Co-Supervisor:

• Institution:

  Faculdade de Ciências - Universidade de Lisboa

• Host Institution:

  FCUL/Institute of Astrophysics and Space Sciences

• Abstract:

  What are the physical drivers of galaxy formation and evolution? How much (and why) did galaxies like our own change across cosmic time (e.g. metallicities, stellar mass, gas fractions)? When, how and through which physical mechanisms are galaxies “quenched”? In order to make progress, the student will explore our unique, large >10 deg^2 narrow-band surveys that have yielded 1000s of galaxies (similar to the Milky Way), selected in the same way across the last 12 billion years (with WIRCam/CFHT and WFCAM/UKIRT) with Hα,Hβ+[OIII] and [OII]. These are ideal samples to study the metallicities, dust extinction, clustering and evolution of “typical” star-forming galaxies all the way to z~5. By using observations that have already been taken (e.g. MOSFIRE and DEIMOS/Keck, FMOS/Subaru, and VIMOS/VLT), the student will be able to gain unprecedentedly detailed information on a large sample of galaxies. These will not only improve our understanding of the number counts, luminosity function and evolution of all major emission lines, which is of upmost importance for planning dark energy experiments such as EUCLID and WFIRST, but will also prepare the first samples that will be explored with MOONS (part of the data were already used to develop the MOONS science case). The student will be able to answer many key questions: 1) What are the typical halo masses for which different star-forming galaxies reside in? 2) How strong is their evolution in metallicity and amount of dust across cosmic time? 3) How biased is our understanding of star formation at high-z based on UV surveys only? Answers to these questions using our well selected samples will provide some of the strongest tests/constraints to the most sophisticated models of galaxy formation and evolution (e.g. EAGLE, Illustris). The results will also be fully compared and contrasted to the best surveys at z~0. By selection, all of the targets have known emission line fluxes and are selected in the same way, thus being extremely competitive against any other method of selection and follow-up. Another unique aspect of this project is that there are significant over-densities in the very large samples of line emitters, and thus the student will be able to confirm and characterise the high redshift structures, derive accurate metallicities, measure the mass-metallicity relation and identify AGN for a sample of hundreds of emission-line selected galaxies and investigate if the environment plays a role in the evolution of these galaxies. Several detailed follow-up studies are foreseen, particularly with X-SHOOTER, MOSFIRE and other instruments. The student will also work on preparing the first targets for MOONS and collaborate in the production of a fully working pipeline for the instrument, and thus will be in an ideal position to explore the new instrument when MOONS becomes available by ~ 2018-2019, but also to be in a leading position when EUCLID starts observing in early 2020.