2018/11/30 by Raymond G. Carlberg, R. G. Carlberg
Physics and Astronomy · #Computer science #Environmental science #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #STREAMS #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/ab61f0
ApJ accepted. Fig1 movies available at https://www.astro.utoronto.ca/~carlberg/movie60_461.mp4 and movie10_461.mmp4 (+/-60 and 10 kpc boxes centered on star cluster)
arxiv created 2019/12/07 · openalex publication_date 2020/01/29 · arxiv updated 2021/01/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract Star particles in a set of dense clusters are self-consistently evolved within an LCDM dark matter distribution with an n -body code. The clusters are started on nearly circular orbits in the more massive sub-halos. Each cluster develops a stellar tidal stream, initially within its original sub-halo. When a sub-halo merges into the main halo the early time stream is dispersed as a somewhat chaotic thick stream, roughly the width of the orbit of the cluster in the sub-halo. Once the cluster orbits freely in the main halo the star stream forms a thin stream again, usually resulting in a thin stream surrounded by a wider distribution of star particles lost at earlier times. To examine the role of the lower-mass dark matter sub-halos in the creation of density variations along the thin tidal star streams two realizations of the simulation are run with and without a normal cold dark matter sub-halo population below 4 × 10 8 . About 70(40)% of thin streams show density variations that are 2(5) times the star count noise level, irrespective of the presence or absence of low-mass sub-halos. A counts-in-cells analysis (related to the two-point correlation function and power spectrum) of the density along nearly 8000° of streams in the two well matched models finds that the full sub-halo population leads to slightly larger, but statistically significant, density fluctuations on scales of 2°–6°.