Skip to main content

Research Repository

Advanced Search

Velocity-dependent J-factors for annihilation radiation from cosmological simulations

Board, Erin; Bozorgnia, Nassim; Strigari, Louis E.; Grand, Robert J.J.; Fattahi, Azadeh; Frenk, Carlos S.; Marinacci, Federico; Navarro, Julio F.; Oman, Kyle A.

Velocity-dependent J-factors for annihilation radiation from cosmological simulations Thumbnail


Authors

Erin Board

Nassim Bozorgnia

Louis E. Strigari

Robert J.J. Grand

Federico Marinacci

Julio F. Navarro

Profile Image

Dr Kyle Oman kyle.a.oman@durham.ac.uk
Assistant Professor - Royal Society Dorothy Hodgkin Fellow



Abstract

We determine the dark matter pair-wise relative velocity distribution in a set of Milky Way-like halos in the Auriga and APOSTLE simulations. Focusing on the smooth halo component, the relative velocity distribution is well-described by a Maxwell-Boltzmann distribution over nearly all radii in the halo. We explore the implications for velocity-dependent dark matter annihilation, focusing on four models which scale as different powers of the relative velocity: Sommerfeld, s-wave, p-wave, and d-wave models. We show that the J -factors scale as the moments of the relative velocity distribution, and that the halo-to-halo scatter is largest for d-wave, and smallest for Sommerfeld models. The J -factor is strongly correlated with the dark matter density in the halo, and is very weakly correlated with the velocity dispersion. This implies that if the dark matter density in the Milky Way can be robustly determined, one can accurately predict the dark matter annihilation signal, without the need to identify the dark matter velocity distribution in the Galaxy.

Citation

Board, E., Bozorgnia, N., Strigari, L. E., Grand, R. J., Fattahi, A., Frenk, C. S., …Oman, K. A. (2021). Velocity-dependent J-factors for annihilation radiation from cosmological simulations. Journal of Cosmology and Astroparticle Physics, 2021(04), Article 070. https://doi.org/10.1088/1475-7516/2021/04/070

Journal Article Type Article
Acceptance Date Mar 24, 2021
Online Publication Date Apr 27, 2021
Publication Date Apr 1, 2021
Deposit Date Jul 22, 2021
Publicly Available Date Apr 27, 2022
Journal Journal of Cosmology and Astroparticle Physics
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 2021
Issue 04
Article Number 070
DOI https://doi.org/10.1088/1475-7516/2021/04/070
Related Public URLs https://arxiv.org/pdf/2101.06284.pdf

Files

Accepted Journal Article (4.8 Mb)
PDF

Copyright Statement
This is an author-created, un-copyedited version of an article published in Journal of Cosmology and Astroparticle Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version
derived from it. The Version of Record is available online at https://doi.org/10.1088/1475-7516/2021/04/070.





You might also like



Downloadable Citations