Constraints on the Self-Interaction Cross-Section of Dark Matter from Numerical Simulations of the Merging Galaxy Cluster 1E 0657-5
read the original abstract
(Abridged) We compare recent results from X-ray, strong lensing, weak lensing, and optical observations with numerical simulations of the merging galaxy cluster 1E0657-56. X-ray observations reveal a bullet-like subcluster with a prominent bow shock, 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, sigma/m, using simplified analytic techniques. In this work, we take advantage of new, higher-quality observational datasets by running N-body simulations of 1E0657-56 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 sigma/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 sigma/m < 1.25 cm^2/g. 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 sigma/m < 0.7 cm^2/g, which comes from the consistency of the subcluster's observed mass-to-light ratio with the main cluster's, and with the universal cluster value, ruling out the possibility of a large fraction of dark matter particles being scattered away due to collisions. Our limit is a slight improvement over the previous result from analytic estimates, and rules out most of the 0.5 - 5cm^2/g range invoked to explain inconsistencies between the standard collisionless cold dark matter model and observations.
This paper has not been read by Pith yet.
Forward citations
Cited by 8 Pith papers
-
Near-IR Weak-lensing (NIRWL) Measurements in the CANDELS Fields. II. Mass Mapping and Overdensity Characterization
First near-IR weak-lensing analysis of CANDELS fields detects 12 shear-selected overdensities with masses 0.2-2.2 x 10^14 solar masses at redshifts 0.22-0.9 and mean z=0.68.
-
Reionization Topology as a Probe of Self-Interacting Dark Matter
Self-interacting dark matter increases the Euler characteristic of the reionization ionization field by 60-70% for cross-sections above 2 cm2/g through changes in ionizing source populations.
-
Breaking the UV Luminosity Function Degeneracy:Self-Interacting Dark Matter Constraints from Reionization Topology
21 cm reionization topology breaks the degeneracy between self-interacting dark matter and astrophysical parameters that limits UV luminosity function constraints, enabling robust SIDM limits of σ/m ≳ 1-2 cm²/g indepe...
-
Scalar-Mediated Inelastic Dark Matter as a Solution to Small-Scale Structure Anomalies
A scalar-mediated inelastic dark matter model with 100 eV splitting, Z2 symmetry forbidding elastic scattering, and a dimension-5 dipole operator reconciles dwarf galaxy observations with cosmological bounds via reson...
-
Structure-wide dark matter density depletion induced by local degeneracies
Degeneracy-induced depletion from fermionic DM in subhalos creates structure-wide low-density cores consistent with observations, linking profile diversity to formation history.
-
Bayesian analysis of density profile of light dark matter elucidating the properties of dark matter admixed neutron stars in the presence of hyperons
Bayesian analysis finds that the likely ranges of light dark-matter fermion mass and exponential density-profile parameter in hyperon-containing neutron stars are nearly independent of the hadronic model for symmetry-...
-
Nearly Degenerate Majorana Dark Matter and Its Self-Interactions in a Gauged $U(1)_{L_\mu - L_\tau}$ Model
A gauged U(1)_{Lμ-Lτ} model generates nearly degenerate Majorana dark matter whose self-interactions via a light scalar mediator set the relic density, resolve core-cusp anomalies, and fit LZ direct detection plus muo...
-
Imprints of energy injection by compact dark stars in the 21-cm signal
Compact dark stars from asymmetric dark matter may inject energy that significantly deviates the 21-cm brightness temperature evolution from standard cosmology, offering a new probe for particle dark matter.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.