The nongravitational interactions of dark matter in colliding galaxy clusters

Harvey, D; Massey, R; Kitching, T; Taylor, A; Tittley, E

doi:10.1126/science.1261381

The nongravitational interactions of dark matter in colliding galaxy clusters

Harvey, D; Massey, R; Kitching, T; Taylor, A; Tittley, E

Authors

D Harvey

Professor Richard Massey r.j.massey@durham.ac.uk
Professor

T Kitching

A Taylor

E Tittley

Abstract

Collisions between galaxy clusters provide a test of the nongravitational forces acting on dark matter. Dark matter’s lack of deceleration in the “bullet cluster” collision constrained its self-interaction cross section σDM/m < 1.25 square centimeters per gram (cm2/g) [68% confidence limit (CL)] (σDM, self-interaction cross section; m, unit mass of dark matter) for long-ranged forces. Using the Chandra and Hubble Space Telescopes, we have now observed 72 collisions, including both major and minor mergers. Combining these measurements statistically, we detect the existence of dark mass at 7.6σ significance. The position of the dark mass has remained closely aligned within 5.8 ± 8.2 kiloparsecs of associated stars, implying a self-interaction cross section σDM/m < 0.47 cm2/g (95% CL) and disfavoring some proposed extensions to the standard model.

Citation

Harvey, D., Massey, R., Kitching, T., Taylor, A., & Tittley, E. (2015). The nongravitational interactions of dark matter in colliding galaxy clusters. Science, 347(6229), 1462-1465. https://doi.org/10.1126/science.1261381

Journal Article Type	Article
Acceptance Date	Feb 12, 2015
Online Publication Date	Mar 27, 2015
Publication Date	Mar 27, 2015
Deposit Date	Dec 10, 2014
Publicly Available Date	Apr 10, 2015
Journal	Science
Print ISSN	0036-8075
Electronic ISSN	1095-9203
Publisher	American Association for the Advancement of Science
Peer Reviewed	Peer Reviewed
Volume	347
Issue	6229
Pages	1462-1465
DOI	https://doi.org/10.1126/science.1261381
Related Public URLs	https://arxiv.org/abs/1503.07675