Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group?

Details Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group? Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group?

2007-05-03

arxiv.org/abs/0705.0530v4

Astronomy and Astrophysics

Astrophysics

11 pages, 7 figures. Accepted for publication in MNRAS. Methodology section rewritten for clarity, results and conclusions unc

Scientific paper

10.1111/j.1365-2966.2007.12279.x

The reionization of the Universe has profound effects on the way galaxies form and on their observed properties at later times. Of particular importance is the relative timing of the reionization history of a region and its halo assembly history, which can affect the nature of the first stars formed in that region, the properties and radial distribution of its stellar halo, globular cluster population and its satellite galaxies. We distinguish two basic cases for the reionization of a halo - internal reionization, whereby the stars forming in situ reionize their host galaxy, and external reionization, whereby the progenitor of a galaxy is reionized by external radiation before its own stars are able to form in sufficient numbers. We use a set of large-scale radiative transfer and structure formation simulations, based on cosmologies derived from both WMAP 1-year and WMAP 3-year data, to evaluate the mean reionization redshifts and the probability of internal/external reionization for Local Group-like systems, galaxies in the field and central cD galaxies in clusters. We find that these probabilities are strongly dependent on the underlying cosmology and the efficiency of photon production, but also on the halo mass. There is a rapid transition between predominantly external and predominantly internal reionization at a mass scale of 1.0e12 Msun (corresponding roughly to L*galaxies), with haloes less massive than this being reionized preferentially from distant sources. We provide a fit for the reionization redshift as a function of halo mass, which could be helpful to parameterize reionization in semi-analytical models of galaxy formation on cosmological scales. We find no statistical correlation between the reionization history of field galaxies and their environment.

Affiliated with

Also associated with

No associations

Rating

Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dependence of the Local Reionization History on Halo Mass and Environment: Did Virgo Reionize the Local Group? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-614939