The local dark matter distribution in self-interacting dark matter halos

Rahimi, Ebrahim; Vienneau, Evan; Bozorgnia, Nassim; Robertson, Andrew

doi:10.1088/1475-7516/2023/02/040

Cited by 6 publications

(3 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The APOSTLE suite includes 12 LG-like volumes, but for this study we only use 4 volumes that have been simulated at all three resolution levels, both as DMO and Hydro. This enables us to check the sensitivity of our results to numerical limitations.…”

Section: Simulationsmentioning

confidence: 99%

“…It assumes that DM is distributed in an isotropic and isothermal sphere around the center of the Galaxy, and that the "local" DM velocity distribution (i.e., in the Solar neighbourhood) may be modelled as a Maxwell-Boltzmann distribution with a peak speed close to the local circular speed. Recent high resolution simulations of galaxy formation, which include both DM and baryons, find that a Maxwellian distribution fits well the local DM velocity distribution of simulated MW-like halos [6][7][8][9][10][11][12]. However, simulations show large halo-to-halo scatter, which leads to a large range of best fit peak speeds for the local Maxwellian velocity distribution.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Are there any extragalactic high speed dark matter particles in the Solar neighborhood?

Santos-Santos,

Bozorgnia,

Fattahi

et al. 2024

J. Cosmol. Astropart. Phys.

Self Cite

View full text Add to dashboard Cite

We use the APOSTLE suite of cosmological hydrodynamical simulations of the Local Group to examine the high speed tail of the local dark matter velocity distribution in simulated Milky Way analogues. The velocity distribution in the Solar neighborhood is well approximated by a generalized Maxwellian distribution sharply truncated at a well-defined maximum “escape” speed. The truncated generalized Maxwellian distribution accurately models the local dark matter velocity distribution of all our Milky Way analogues, with no evidence for any separate extragalactic high-speed components. The local maximum speed is well approximated by the terminal velocity expected for particles able to reach the Solar neighborhood in a Hubble time from the farthest confines of the Local Group. This timing constraint means that the local dark matter velocity distribution is unlikely to contain any high-speed particles contributed by the Virgo Supercluster “envelope”, as argued in recent work. Particles in the Solar neighborhood with speeds close to the local maximum speed can reach well outside the virial radius of the Galaxy, and, in that sense, belong to the Local Group envelope posited in earlier work. The local manifestation of such envelope is thus not a distinct high-speed component, but rather simply the high-speed tail of the truncated Maxwellian distribution.

show abstract

Section: Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Are there any extragalactic high speed dark matter particles in the Solar neighborhood?

Santos-Santos,

Bozorgnia,

Fattahi

et al. 2024

J. Cosmol. Astropart. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Such studies were performed not only with DM-only (DMO) simulations but also within hydrodynamical cosmological simulations (e.g. Vogelsberger et al 2014;Robertson et al 2019Robertson et al , 2020Rose et al 2022;Mastromarino et al 2023;Rahimi et al 2023). They are well-motivated for different angular dependencies, including forward-enhanced crosssections from light mediator models (e.g.…”

Section: Introductionmentioning

confidence: 99%

Cosmological simulations with rare and frequent dark matter self-interactions

Fischer

Brüggen

Schmidt-Hoberg

et al. 2022

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Dark matter (DM) with self-interactions is a promising solution for the small-scale problems of the standard cosmological model. Here we perform the first cosmological simulation of frequent DM self-interactions, corresponding to small-angle DM scatterings. The focus of our analysis lies in finding and understanding differences to the traditionally assumed rare DM (large-angle) self scatterings. For this purpose, we compute the distribution of DM densities, the matter power spectrum, the two-point correlation function and the halo and subhalo mass functions. Furthermore, we investigate the density profiles of the DM haloes and their shapes. We find that overall large-angle and small-angle scatterings behave fairly similarly with a few exceptions. In particular, the number of satellites is considerably suppressed for frequent compared to rare self-interactions with the same cross-section. Overall we observe that while differences between the two cases may be difficult to establish using a single measure, the degeneracy may be broken through a combination of multiple ones. For instance, the combination of satellite counts with halo density or shape profiles could allow discriminating between rare and frequent self-interactions. As a by-product of our analysis, we provide - for the first time - upper limits on the cross-section for frequent self-interactions.

show abstract

The impact of baryonic potentials on the gravothermal evolution of self-interacting dark matter haloes

Zhong,

Yang,

2023

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The presence of a central baryonic potential can have a significant impact on the gravothermal evolution of self-interacting dark matter (SIDM) haloes. We extend a semi-analytical fluid model to incorporate the influence of a static baryonic potential and calibrate it using controlled N-body simulations. We construct benchmark scenarios with varying baryon concentrations and different SIDM models, including constant and velocity-dependent self-interacting cross-sections. The presence of the baryonic potential induces changes in SIDM halo properties, including central density, core size, and velocity dispersion, and it accelerates the halo’s evolution in both expansion and collapse phases. Furthermore, we observe a quasi-universality in the gravothermal evolution of SIDM haloes with the baryonic potential, resembling a previously known feature in the absence of the baryons. By appropriately rescaling the physical quantities that characterize the SIDM haloes, the evolution of all our benchmark cases exhibits remarkable similarity. Our findings offer a framework for testing SIDM predictions using observations of galactic systems where baryons play a significant dynamical role.

show abstract

The local dark matter distribution in self-interacting dark matter halos

Cited by 6 publications

References 83 publications

Are there any extragalactic high speed dark matter particles in the Solar neighborhood?

Are there any extragalactic high speed dark matter particles in the Solar neighborhood?

Cosmological simulations with rare and frequent dark matter self-interactions

The impact of baryonic potentials on the gravothermal evolution of self-interacting dark matter haloes

Contact Info

Product

Resources

About