A signature of the internal reionisation of the Milky Way?

Details A signature of the internal reionisation of the Milky Way? A signature of the internal reionisation of the Milky Way?

2011-08-04

arxiv.org/abs/1108.1193v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Accepted for publication in Letters of the Monthly Notices of the Royal Astronomical Society. 6 pages, 3 figures

Scientific paper

We present a new semi-analytical model of the population of satellite galaxies of the Milky Way, aimed at estimating the effect of the spatial structure of reionisation at galaxy scale on the properties of the satellites. In this model reionisation can be either: (A) externally-driven and uniform, or (B) internally-driven, by the most massive progenitor of the Milky-Way. In the latter scenario the propagation of the ionisation front and photon dilution introduce a delay in the photo-evaporation of the outer satellites' gas with respect to the inner satellites. As a consequence, outer satellites experience a longer period of star formation than those in the inner halo. We use simple models to account for star formation, the propagation of the ionisation front, photo-evaporation and observational biases. Both scenarios yield a model satellite population at z=0 that matches the observed luminosity function and mass-to-light ratios. However, the predicted population for scenario (B) is significantly more extended spatially than for scenario (A), by about 0.3 dex in distance, resulting in a much better match to the observations. The survival of this structural signature imprinted by the local UV field during reionisation on the radial distribution of satellites makes it a promising tool for studying the reionisation epoch at galaxy scale in the Milky Way and nearby galaxies resolved in stars with forthcoming large surveys. However, more work is needed to determine how the effect reported here can be disentangled from that of cosmic variance between different realisations of Milky Way haloes.

Affiliated with

Also associated with

No associations

Rating

A signature of the internal reionisation of the Milky Way? 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 A signature of the internal reionisation of the Milky Way?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A signature of the internal reionisation of the Milky Way? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-667483