2011/09/30 by Raymond G. Carlberg, R. G. Carlberg · 1 citation
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Advanced Fluorescence Microscopy Techniques #Astronomy #Astrophysics #CCD and CMOS Imaging Sensors #Dark matter #Dark matter halo #Galactic halo #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Milky Way #Physics #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/748/1/20
ApJ accepted and copy-edited
arxiv created 2011/12/17 · openalex publication_date 2012/03/01 · arxiv updated 2015/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Dark matter sub-halos create gaps in the stellar streams orbiting in the halos of galaxies. We evaluate the sub-halo stream crossing integral with the guidance of simulations to find that the linear rate of gap creation, , in a typical cold dark matter (CDM) galactic halo at 100 kpc is , where ) is the minimum mass halo that creates a visible gap. The relation can be recast entirely in terms of observables, as , for w in kpc, normalized at 100 kpc. Using published data, the density of gaps is estimated for M31's NW stream and the Milky Way Pal 5 stream, Orphan stream, and Eastern Banded Structure. The estimated rates of gap creation all have errors of 50% or more due to uncertain dynamical ages and the relatively noisy stream density measurements. The gap-rate–width data are in good agreement with the CDM-predicted relation. The high density of gaps in the narrow streams requires a total halo population of 10 5 sub-halos above a minimum mass of 10 5 M ☉ .