Constraints on the identity of the dark matter from strong gravitational lenses

Li, R.; Frenk, C.S.; Cole, S.; Gao, L.; Bose, S.; Hellwing, W.A.

Abstract

The cold dark matter (CDM) cosmological model unambiguously predicts that a large number of haloes should survive as subhaloes when they are accreted into a larger halo. The CDM model would be ruled out if such substructures were shown not to exist. By contrast, if the dark matter consists of Warm Dark Matter (WDM) particles, then below a threshold mass that depends on the particle mass far fewer substructures would be present. Finding subhaloes below a certain mass would then rule out warm particle masses below some value. Strong gravitational lensing provides a clean method to measure the subhalo mass function through distortions in the structure of Einstein rings and giant arcs. Using mock lensing observations constructed from high-resolution N-body simulations, we show that measurements of approximately 100 strong lens systems with a detection limit of Mlow = 107 h−1 M⊙ would clearly distinguish CDM from WDM in the case where this consists of 7 keV sterile neutrinos such as those that might be responsible for the 3.5 keV X-ray emission line recently detected in galaxies and clusters.

Citation

Li, R., Frenk, C., Cole, S., Gao, L., Bose, S., & Hellwing, W. (2016). Constraints on the identity of the dark matter from strong gravitational lenses. Monthly Notices of the Royal Astronomical Society, 460(1), 363-372. https://doi.org/10.1093/mnras/stw939

• Journal Article Type: Article
• Acceptance Date: Apr 19, 2016
• Online Publication Date: Apr 21, 2016
• Publication Date: Jul 21, 2016
• Deposit Date: May 24, 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: 460
• Issue: 1
• Pages: 363-372
• DOI: https://doi.org/10.1093/mnras/stw939
• Public URL: https://durham-repository.worktribe.com/output/1380899