Counting Dark Sub-halos with Star Stream Gaps

Дата и время публикации : 2012-01-06T03:58:44Z

Авторы публикации и институты :
Raymond G. Carlberg

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: contribution to the Third Subaru Conference, Galactic Archaeology: Near Field Cosmology and the Formation of the Milky Way ed. Wako Aoki
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO, astro-ph.GA

Краткий обзор статьи: The Cold Dark Matter paradigm predicts vast numbers of dark matter sub-halos to be orbiting in galactic halos. The sub-halos are detectable through the gaps they create gaps in stellar streams. The gap-rate is an integral over the density of sub-halos, their mass function, velocity distribution and the dynamical age of the stream. The rate of visible gap creation is a function of the width of the stream. The available data for four streams: the NW stream of M31, the Pal~5 stream, the Orphan Stream and the Eastern Banded Structure, are compared to the LCDM predicted relation. We find a remarkably good agreement, although there remains much to be done to improve the quality of the result. The narrower streams require that there is a total population of order 10^5 sub-halos above 10^5 M_sun to create the gaps.

Category: Physics