Constraints on the Self‐Interaction Cross Section of Dark Matter from Numerical Simulations of the Merging Galaxy Cluster 1E 0657−56

Abstract

We compare recent results from X-ray, strong lensing, weak lensing, and optical observations with numerical simulations of the merging galaxy cluster 1E 0657-56. X-ray observations reveal a bullet-like subcluster with a prominent bow shock, which gives an estimate for the merger velocity of 4700 km s −1 , while lensing results show that the positions of the total mass peaks are consistent with the centroids of the collisionless galaxies (and inconsistent with the X-ray brightness peaks). Previous studies, based on older observational datasets, have placed upper limits on the self-interaction cross-section of dark matter per unit mass, σ/m, using simplified analytic techniques. In this work, we take advantage of new, higher-quality observational datasets by running full N-body simulations of 1E 0657-56 that include the effects of self-interacting dark matter, and comparing the results with observations. Furthermore, the recent data allow for a new independent method of constraining σ/m, based on the non-observation of an offset between the bullet subcluster mass peak and galaxy centroid. This new method places an upper limit (68% confidence) of σ/m < 1.25 cm 2 g −1 .If we make the assumption that the subcluster and the main cluster had equal mass-to-light ratios prior to the merger, we derive our most stringent constraint of σ/m < 0.7 cm 2 g −1 , which comes from the consistency of the subcluster's observed mass-to-light ratio with the main cluster's, and with the universal cluster

Complex scalar dark matter in aB-Lmodel

“…In that case, the DM candidate would be the Goldstone boson related to the breakdown of the Uð1Þ χ symmetry. In general, such massless DM has severe constraints from the big bang nucleosynthesis [31,32] and the bullet cluster [14,33]. Here we do not consider this case.…”

Cosmological evolution of finite temperature Bose-Einstein condensate dark matter

“…By comparing results from X-ray, strong lensing, weak lensing, and optical observations with numerical simulations of the merging galaxy cluster 1E 0657-56 (the Bullet cluster), an upper limit (68 % confidence) for σ m of the order of σ m < 1.25 cm 2 /g was obtained in [28]. By adopting for σ m a value of σ m = 1.25 cm 2 /g, we obtain for the mass of the dark matter particle an upper limit of the order m < 3.1933 × 10 −37 R 10 kpc…”

Indirect detection of self-interacting asymmetric dark matter

“…In the limit m Sv /m σ 1, which will be valid for our parameters, these differ by O(1) [45] and so we will ignore this complication.) The bullet cluster bound requires σ SS /m S < ∼ .7 cm 2 /g [46], and bounds from the evaporation of galactic halos favor σ SS / m S < ∼ .1 cm 2 /g [34]. These bounds appear to be in conflict with the prefered range to eliminate cuspy profiles, .56 cm 2 /g < ∼ σ SS /m S < ∼ 5.6 cm 2 /g [23,24].…”