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Title: The reionization of galactic satellite populations

We use high-resolution simulations of the formation of the local group, post-processed by a radiative transfer code for UV photons, to investigate the reionization of the satellite populations of an isolated Milky Way-M31 galaxy pair in a variety of scenarios. We use an improved version of ATON which includes a simple recipe for radiative feedback. In our baseline models, reionization is initiated by low-mass, radiatively regulated halos at high redshift, until more massive halos appear, which then dominate and complete the reionization process. We investigate the relation between reionization history and present-day positions of the satellite population. We find that the average reionization redshift (z {sub r}) of satellites is higher near galaxy centers (MW and M31). This is due to the inside out reionization patterns imprinted by massive halos within the progenitor during the epoch of reionization, which end up forming the center of the galaxy. Due to incomplete dynamical mixing during galaxy assembly, these early patterns survive to present day, resulting in a clear radial gradient in the average satellite reionization redshift, up to the virial radius of MW and M31 and beyond. In the lowest emissivity scenario, the outer satellites are reionized about 180 Myr later thanmore » the inner satellites. This delay decreases with increasing source model emissivity, or in the case of external reionization by Virgo or M31, because reionization occurs faster overall and becomes spatially quasi-uniform at the highest emissivity.« less
Authors:
; ; ;  [1] ; ;  [2] ; ;  [3] ;  [4]
  1. Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS UMR 7550, 11 rue de l'Université, F-67000 Strasbourg (France)
  2. Grupo de Astrofísica, Departamento de Fisica Teorica, Modulo C-8, Universidad Autónoma de Madrid, Cantoblanco E-280049 (Spain)
  3. Leibniz-Institute für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)
  4. Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)
Publication Date:
OSTI Identifier:
22370508
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMOLOGY; EMISSIVITY; FEEDBACK; GALAXIES; MASS; MILKY WAY; MIXING; PHOTONS; RADIANT HEAT TRANSFER; RED SHIFT; RESOLUTION; SATELLITES; SIMULATION