Cosmological Zoom-In Simulations of Milky Way Host Mass Dark Matter Halos with a Blue-Tilted Primordial Power Spectrum

Abstract

Recent observations from the James Webb Space Telescope revealed a surprisingly large number of galaxies at high redshift, challenging the standard Lambda Cold Dark Matter cosmology with a power-law primordial power spectrum. Previous studies alleviated this tension with a blue tilted primordial power spectrum ($P(k)\propto k^{m_s}$ with $m_s>1$ at small scales $>1{\mathrm{cMpc}}^{-1}$). In this study, we examine whether the blue tilted model can boost dark matter substructures especially at low redshift, thereby addressing other potential challenges to the standard cosmology. First, substructures in the standard cosmological model may not be sufficient to explain the anomalous flux ratio problem observed in strong gravitational lensing. Second, the number of observed nearby satellite galaxies could be higher than the theoretical predictions of the standard cosmology, after completeness correction and tidal stripping by baryonic disks. To study the impact of a blue tilted primordial power spectrum on substructures, we perform high-resolution cosmological zoom-in dark matter-only simulations of Milky Way host mass halos, evolving to redshift $z=0$. At $z=0$, we find that the blue-tilted subhalo mass functions can be enhanced by more than a factor of two for subhalo masses $M_{\mathrm{sub}}\lesssim 10^{10}M\odot$, whereas the subhalo $V_{\max }$ functions can be enhanced by a factor of four for maximum circular velocities $V_{\max }\lesssim 30km/s$. The blue-tilted scaled cumulative substructure fraction can be an order of magnitude higher at $\sim$10\% of the virial radius. The blue-tilted subhalos also have higher central densities, since the blue-tilted subhalos reach the same $V_{\max }$ at a smaller distance $R_{\max }$ from the center. We have also verified these findings with higher-resolution simulations.

24 pages, 18 figures; based on the version published in PRD, with added code and data availability statements

References in corpus (24)

• The NumPy array: a structure for efficient numerical computation
• The James Webb Space Telescope
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• A population of red candidate massive galaxies ~600 Myr after the Big Bang
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• The Origin of the Galaxy Mass-Metallicity Relation and Implications for Galactic Outflows
• The halo mass function from the dark ages through the present day
• A universal model for halo concentrations
• Stress Testing $\Lambda$CDM with High-redshift Galaxy Candidates
• The FLAMINGO project: cosmological hydrodynamical simulations for large-scale structure and galaxy cluster surveys
• Extreme Value Statistics of the Halo and Stellar Mass Distributions at High Redshift: are JWST Results in Tension with ΛCDM?
• Public data release of the FIRE-2 cosmological zoom-in simulations of galaxy formation
• HBT+: an improved code for finding subhalos and building merger trees in cosmological simulations
• How well can cold-dark-matter substructures account for the observed radio flux-ratio anomalies?
• SWIFT: A modern highly-parallel gravity and smoothed particle hydrodynamics solver for astrophysical and cosmological applications
• Hunting for Galaxies and Halos in simulations with VELOCIraptor
• Strong lensing signatures of luminous structure and substructure in early-type galaxies
• GRUMPY: a simple framework for realistic forward-modelling of dwarf galaxies
• Subhalo statistics of galactic halos: beyond the resolution limit
• Waterfall field in hybrid inflation and curvature perturbation
• A Parametric Model for Self-Interacting Dark Matter Halos
• Baryonic effects on the detectability of annihilation radiation from dark matter subhaloes around the Milky Way
• Excess of high-$z$ galaxies as a test for bumpy power spectrum of density perturbations
• A too-many dwarf galaxy satellites problem in the M83 group

Cited by in corpus (1)

• Primordial black holes save $R^2$ inflation