Connecting Reionization to the Local Universe

Journal Article · Mon Aug 03 00:00:00 EDT 2009 · Submitted to Astrophysical Journal Letters

DOI:https://doi.org/10.1088/0004-637X/703/2/L167· OSTI ID:962098

Alvarez, Marcelo A; Busha, Michael; Abel, Tom; Wechsler, Risa H

We present results of combined N-body and three-dimensional reionization calculations to determine the relationship between reionization history and local environment in a volume 1 Gpc h{sup -1} across and a resolution of about 1 Mpc. We resolve the formation of about 2 x 10{sup 6} halos of mass greater than {approx} 10{sup 12} M{sub {circle_dot}} at z = 0, allowing us to determine the relationship between halo mass and reionization epoch for galaxies and clusters. For our fiducial reionization model, in which reionization begins at z {approx} 15 and ends by z {approx} 6, we find a strong bias for cluster-size halos to be in the regions which reionized first, at redshifts 10 < z < 15. Consequently, material in clusters was reionized within relatively small regions, on the order of a few Mpc, implying that all clusters in our calculation were reionized by their own progenitors. Milky Way mass halos were on average reionized later and by larger regions, with a distribution most similar to the global one, indicating that low mass halos are nearly uncorrelated with reionization when only their mass is taken as a prior. On average, we find that most halos with mass less than 10{sup 13} M{sub {circle_dot}} were reionized internally, while almost all halos with masses greater than 10{sup 14} M{sub {circle_dot}} were reionized by their own progenitors. We briefly discuss the implications of this work in light of the 'missing satellites' problem and how this new approach may be extended further.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 962098
• Report Number(s): SLAC-PUB-13722; arXiv:0812.3405
• Journal Information: Submitted to Astrophysical Journal Letters, Journal Name: Submitted to Astrophysical Journal Letters
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Astrophysics
DISTRIBUTION
GALAXIES
MILKY WAY
RESOLUTION
SATELLITES
UNIVERSE