View Full Version : Milky Way Dwarfs

2007-Sep-12, 06:24 PM

2007-Sep-13, 02:17 AM
Attached is a link to a preprint of the paper.


Based on the abstract (see below) there still appears to be too few dwarf galaxies by a factor of 4, as compared to theory. The solution to reconcile the discrepancy, the authors of the paper propose, is some mechanism that sharply suppresses formation of galaxies from small mass dark matter halos.


After correcting for the sky coverage of the Sloan Digital Sky Survey, we find that the ultra-faint dwarfs substantially alleviate the discrepancy between the predicted and observed numbers of satellites around the Milky Way, but there are still a factor of ∼ 4 too few dwarf galaxies over a significant range of masses. We show that if galaxy formation in low-mass dark matter halos is strongly suppressed after reionization, the simulated circular velocity function of CDM subhalos can be brought into approximate agreement with the observed circular velocity function of Milky Way satellite galaxies.