English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In an influential recent paper, Harvey et al (2015) derive an upper limit tothe self-interaction cross section of dark matter ($\sigma_{\rm DM} < 0.47$cm$^2$/g at 95\% confidence) by averaging the dark matter-galaxy offsets in asample of merging galaxy clusters. Using much more comprehensive data on thesame clusters, we identify several substantial errors in their offsetmeasurements. Correcting these errors relaxes the upper limit on $\sigma_{\rmDM}$ to $\lesssim 2$ cm$^2$/g, following the Harvey et al prescription forrelating offsets to cross sections in a simple solid body scattering model.Furthermore, many clusters in the sample violate the assumptions behind thisprescription, so even this revised upper limit should be used with caution.Although this particular sample does not tightly constrain self-interactingdark matter models when analyzed this way, we discuss how merger ensembles maybe used more effectively in the future. We conclude that errors inherent inusing single-band imaging to identify mass and light peaks do not necessarilyaverage out in a sample of this size, particularly when a handful ofsubstructures constitute a majority of the weight in the ensemble.

The Mismeasure of Mergers: Revised Limits on Self-interacting Dark Matter in Merging Galaxy Clusters