Friday, 30 January 2009

Another solution to the missing satellite problem

From Busha et al. (

The authors use the Via Lactea + a cosmological N-Body simulation to model the effects of reionization on the dwarf galaxy population. Previous studies have claimed that reionization did not reduce the number of dwarf galaxies enough. They find they can account for a number as well as the distribution of satellites. One particular way they differ from other studies is that other studies allowed pre-reionization collapsed objects to form stars with a much higher effeciency, while they claim that these objects would have their cold gas photo-evaporated on a short timescale.

The above figure shows the sub-halo population from the simulations (solid black line) and their inferred dwarf distribution (linestyles). The observations are given by the points and the cyan region.

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