Dark matter–radiation interactions: the structure of Milky Way satellite galaxies

Schewtschenko, J.A.; Baugh, C.M.; Wilkinson, R.J.; Boehm, C.; Pascoli, S.; Sawala, T.

doi:10.1093/mnras/stw1078

Dark matter–radiation interactions: the structure of Milky Way satellite galaxies

Schewtschenko, J.A.; Baugh, C.M.; Wilkinson, R.J.; Boehm, C.; Pascoli, S.; Sawala, T.

Authors

J.A. Schewtschenko

C.M. Baugh

R.J. Wilkinson

C. Boehm

Professor Silvia Pascoli silvia.pascoli@durham.ac.uk
Visiting Professor

T. Sawala

Abstract

In the thermal dark matter (DM) paradigm, primordial interactions between DM and Standard Model particles are responsible for the observed DM relic density. In Boehm et al. (2014), we showed that weak-strength interactions between DM and radiation (photons or neutrinos) can erase small-scale density fluctuations, leading to a suppression of the matter power spectrum compared to the collisionless cold DM (CDM) model. This results in fewer DM subhaloes within Milky Way-like DM haloes, implying a reduction in the abundance of satellite galaxies. Here we use very high resolution N-body simulations to measure the dynamics of these subhaloes. We find that when interactions are included, the largest subhaloes are less concentrated than their counterparts in the collisionless CDM model and have rotation curves that match observational data, providing a new solution to the “too big to fail” problem.

Citation

Schewtschenko, J., Baugh, C., Wilkinson, R., Boehm, C., Pascoli, S., & Sawala, T. (2016). Dark matter–radiation interactions: the structure of Milky Way satellite galaxies. Monthly Notices of the Royal Astronomical Society, 461(3), 2282-2287. https://doi.org/10.1093/mnras/stw1078

Journal Article Type	Article
Acceptance Date	May 4, 2016
Online Publication Date	May 6, 2016
Publication Date	Sep 21, 2016
Deposit Date	Jun 10, 2016
Publicly Available Date	Jun 16, 2016
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	461
Issue	3
Pages	2282-2287
DOI	https://doi.org/10.1093/mnras/stw1078
Related Public URLs	https://arxiv.org/abs/1512.06774

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Advance online version This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.