The Density Structure of Simulated Stellar Streams

Abstract

Simulations are run with and without a normal cold dark matter sub-halo population below 4x10^8 M_sun to examine the role of the lower mass sub-halos in the creation of density variations, "gaps", within thin tidal star streams. Dense star clusters composed of stellar mass particles are started within a redshift 3 sub-galactic dark matter halo distribution which assembles to create a Milky Way like halo. Hierarchical assembly causes the early-time tidal star streams from the clusters to later be dispersed as thick streams around the thin streams that develop in the main late-time halo as it settles towards equilibrium. The two simulations are set up to be essentially dynamically identical and result in about 140 star clusters within a radius of 50 kpc, of which 40 some have thin tidal streams longer than 40\degr\ with a separation of more than 20\degr\ from the cluster as viewed from the halo center. Averaged over about 20 separate snapshots, the fraction of streams with significant density variations inside 50 kpc is $0.58\pm 0.02$ in the simulation with low mass sub-halos and $0.52\pm 0.02$ in the simulation without low mass halos. That is, only $12\pm 5$\% of the stream density variations can be attributed to the sub-halos below 4x10^8 M_sun. The dominant source of density variations in streams is the varying tidal fields along the complex trajectories of the clusters and their streams as the galaxy assembles.

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)

References in corpus (20)

• Evidence for Two Early Accretion Events That Built the Milky Way Stellar Halo
• Origin of the system of globular clusters in the Milky Way
• The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
• The Spur and the Gap in GD-1: Dynamical evidence for a dark substructure in the Milky Way halo
• Dark matter subhalos and the dwarf satellites of the Milky Way
• Dark Matter Halos in Galaxies and Globular Cluster Populations
• Phat ELVIS: The inevitable effect of the Milky Way's disk on its dark matter subhaloes
• On the structure of tidal tails
• A Synoptic Map of Halo Substructures from the Pan-STARRS1 3π Survey
• Forensics of Subhalo-Stream Encounters: The Three Phases of Gap Growth
• The Radical Consequences of Realistic Satellite Orbits for the Heating and Implied Merger Histories of Galactic Disks
• Milky Way Mass and Potential Recovery Using Tidal Streams in a Realistic Halo
• Effects of baryonic and dark matter substructure on the Pal 5 stream
• Star cluster formation in cosmological simulations. III. Dynamical and chemical evolution
• Formation histories of stars, clusters and globular clusters in the E-MOSAICS simulations
• Butterfly in a Cocoon, Understanding the origin and morphology of Globular Cluster Streams: The case of GD-1
• Searching for the GD-1 Stream Progenitor in Gaia DR2 with Direct N-body Simulations
• Modeling the gravitational potential of a cosmological dark matter halo with stellar streams
• Simulating tidal streams in a high resolution dark matter halo
• Quantifying tidal stream disruption in a simulated Milky Way

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