Universal subhalo accretion in cold and warm dark matter cosmologies

Abstract

The influence of the large scale structure on host halos may be studied by examining the angular infall pattern of subhalos. In particular, since warm and cold dark matter cosmologies predict different abundances and internal properties for halos at the low mass end of the mass function, it is interesting to examine if there are differences in how these low mass halos are accreted. The accretion events are defined as the moment a halo becomes a substructure, namely when it crosses its host's virial radius. We quantify the cosmic web at each point by the shear tensor and examine where, with respect to its eigenvectors, such accretion events occur in cold ($\Lambda$CDM) and warm (1keV sterile neutrino WDM) dark matter cosmological models. We find that the CDM and WDM subhalos are preferentially accreted along the principal axis of the shear tensor corresponding to the direction of weakest collapse. The beaming strength is modulated by the host and subhalo masses and by the redshift at which the accretion event occurs. Although strongest for the most massive hosts and subhalos at high redshift, the preferential infall is found to be always aligned with the axis of weakest collapse, thus we say that it has universal nature. We compare the strength of beaming in the WDM cosmology with the one found in the $\Lambda$CDM scenario. While the main findings remain the same, the accretion in the WDM model for the most massive host halos appears more beamed than in $\Lambda$CDM cosmology across all the redshifts.

12 pages, 9 figures

References in corpus (21)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Cosmological Constraints from the SDSS Luminous Red Galaxies
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• Properties of Dark Matter Haloes in Clusters, Filaments, Sheets and Voids
• Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function
• Too Big to Fail in the Local Group
• Discreteness effects in simulations of Hot/Warm dark matter
• Is there a "too big to fail" problem in the field?
• Multi-Component Dark Matter
• The velocity function in the local environment from LCDM and LWDM constrained simulations
• The Invisibles: A Detection Algorithm to Trace the Faintest Milky Way Satellites
• Resonantly-Produced 7 keV Sterile Neutrino Dark Matter Models and the Properties of Milky Way Satellites
• Two Planes of Satellites in the Centaurus A Group
• Dark Matter Heating and Early Core Formation in Dwarf Galaxies
• M31 Satellite Masses Compared to LCDM Subhaloes
• The universal nature of subhalo accretion
• Alignment between galaxies and large-scale structure
• Expanded haloes, abundance matching and too-big-to-fail in the Local Group
• Comparing the observable properties of dwarf galaxies on and off the Andromeda plane
• Revisiting Multi-Component Dark Matter with New AMS-02 Data

Cited by in corpus (4)

• The Hestia project: simulations of the Local Group
• The effect of tides on the Sculptor dwarf spheroidal galaxy
• Anisotropic satellite accretion onto the Local Group with HESTIA
• Mock Observations: Three Different Types of Galaxy Alignment in TNG100 Simulations