Dark Matter Annihilation Feedback in Cosmological Simulations II: The Influence on Gas and Halo Structure

Abstract

We present new cosmological hydrodynamic simulations that incorporate Dark Matter Annihilation Feedback (DMAF), whereby energy released from the annihilation of dark matter particles through decay channels such as photon or positron-electron pairs provide additional heating sources for local baryonic material. For annihilation rates comparable to WIMP-like particles, we find that the key influence of DMAF is to inhibit gas accretion onto halos. Such diminished gas accretion early in the lifetimes of halos results in reduced gas fractions in smaller halos, and the delayed halo formation times of larger structures, suggesting that DMAF could impact the stellar age distribution in galaxies, and morphology of dwarfs. For a dark matter particle mass of $m_{\chi }\sim 10$~MeV, there is a `critical halo mass' of $\sim 10^{13}$ M${}_{\odot }$ at $z=0$, below which there are large differences when compared to $\Lambda$CDM, such as a reduction in the abundance of halo structures as large as 25 percent, reduced gas content by 50 percent and central gas densities reduced down to 10 percent within halos of mass $\sim 10^{12}$ M${}_{\odot }$ but with increasing effects in smaller halos. Higher dark matter particle mass models have a smaller `critical halo mass'. For a $m_{\chi }\sim 100$~MeV model, we find differences start appearing below halo masses of $\sim 10^{12}$ M${}_{\odot }$ and a $m_{\chi }\gtrsim 1$~GeV model, this mass scale lies below the resolution of our simulations, though we still observe changes in the morphology of dwarf galaxies.

16 pages, 12 figures

References in corpus (22)

• Dark Matter Candidates from Particle Physics and Methods of Detection
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Astrophysics Source Code Library
• Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• High-resolution mass models of dwarf galaxies from LITTLE THINGS
• The role of stellar feedback in the formation of galaxies
• Is dark matter with long-range interactions a solution to all small-scale problems of ΛCDM cosmology?
• Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter
• Effects of cold dark matter decoupling and pair annihilation on cosmological perturbations
• Cold keV dark matter from decays and scatterings
• Cosmological particle-in-cell simulations with ultralight axion dark matter
• SIDM on FIRE: Hydrodynamical Self-Interacting Dark Matter simulations of low-mass dwarf galaxies
• The impact of dark matter decays and annihilations on the formation of the first structures
• SURFS: Riding the waves with Synthetic UniveRses For Surveys
• The roles of stellar feedback and galactic environment in star forming molecular clouds
• A dark matter model that reconciles tensions between the cosmic-ray $e^{\pm }$ excess and the gamma-ray and CMB constraints
• nIFTy galaxy cluster simulations V: Investigation of the Cluster Infall Region
• Effect of dark matter annihilation on gas cooling and star formation
• Consequences of dark matter self-annihilation for galaxy formation
• Dark Matter Annihilation in the Circumgalactic Medium at High Redshifts
• Dark Matter Annihilation Feedback in cosmological simulations I: Code convergence and idealised halos

Cited by in corpus (1)

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