scholarly journals Restrictions on parameters of sterile neutrino dark matter from observations of galaxy clusters

2006 ◽  
Vol 74 (10) ◽  
Author(s):  
A. Boyarsky ◽  
A. Neronov ◽  
O. Ruchayskiy ◽  
M. Shaposhnikov
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Sterile Neutrino

scholarly journals The XMM Cluster Survey: new evidence for the 3.5-keV feature in clusters is inconsistent with a dark matter origin

2020 ◽  
Vol 497 (1) ◽  
pp. 656-671 ◽  
Author(s):  
S Bhargava ◽  
P A Giles ◽  
A K Romer ◽  
T Jeltema ◽  
J Mayers ◽  
...  
Keyword(s):  
Dark Matter ◽  
Emission Line ◽  
Galaxy Clusters ◽  
Sterile Neutrino ◽  
Significant Excess ◽  
Mixing Angle ◽  
X Ray ◽  
Cluster Survey ◽  
Upper Limit ◽  
New Evidence

ABSTRACT There have been several reports of a detection of an unexplained excess of X-ray emission at $\simeq$3.5 keV in astrophysical systems. One interpretation of this excess is the decay of sterile neutrino dark matter. The most influential study to date analysed 73 clusters observed by the XMM–Newton satellite. We explore evidence for a ≃3.5-keV excess in the XMM-PN spectra of 117 redMaPPer galaxy clusters (0.1 < z < 0.6). In our analysis of individual spectra, we identify three systems with an excess of flux at $\simeq$3.5 keV. In one case (XCS J0003.3+0204), this excess may result from a discrete emission line. None of these systems are the most dark matter dominated in our sample. We group the remaining 114 clusters into four temperature (TX) bins to search for an increase in ≃3.5-keV flux excess with TX – a reliable tracer of halo mass. However, we do not find evidence of a significant excess in flux at ≃3.5 keV in any TX bins. To maximize sensitivity to a potentially weak dark matter decay feature at ≃3.5 keV, we jointly fit 114 clusters. Again, no significant excess is found at ≃3.5 keV. We estimate the upper limit of an undetected emission line at ≃3.5 keV to be 2.41 × 10−6 photons cm−2 s−1, corresponding to a mixing angle of sin 2(2θ) = 4.4 × 10−11, lower than previous estimates from cluster studies. We conclude that a flux excess at ≃3.5 keV is not a ubiquitous feature in clusters and therefore unlikely to originate from sterile neutrino dark matter decay.

scholarly journals Sterile neutrino dark matter from generalized CPT -symmetric early-Universe cosmologies

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
Adam Duran ◽  
Logan Morrison ◽  
Stefano Profumo
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Sterile Neutrino

scholarly journals Understanding the large inferred Einstein radii of observed low-mass galaxy clusters

2020 ◽  
Vol 494 (4) ◽  
pp. 4706-4712 ◽  
Author(s):  
Andrew Robertson ◽  
Richard Massey ◽  
Vincent Eke
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Gravitational Lensing ◽  
Cold Dark Matter ◽  
Baryonic Matter ◽  
Analysis Method ◽  
Critical Curves ◽  
Hydrodynamical Simulation ◽  
Low Mass ◽  
Main Effects

ABSTRACT We assess a claim that observed galaxy clusters with mass ${\sim}10^{14} \mathrm{\, M_\odot }$ are more centrally concentrated than predicted in lambda cold dark matter (ΛCDM). We generate mock strong gravitational lensing observations, taking the lenses from a cosmological hydrodynamical simulation, and analyse them in the same way as the real Universe. The observed and simulated lensing arcs are consistent with one another, with three main effects responsible for the previously claimed inconsistency. First, galaxy clusters containing baryonic matter have higher central densities than their counterparts simulated with only dark matter. Secondly, a sample of clusters selected because of the presence of pronounced gravitational lensing arcs preferentially finds centrally concentrated clusters with large Einstein radii. Thirdly, lensed arcs are usually straighter than critical curves, and the chosen image analysis method (fitting circles through the arcs) overestimates the Einstein radii. After accounting for these three effects, ΛCDM predicts that galaxy clusters should produce giant lensing arcs that match those in the observed Universe.

scholarly journals Degenerate sterile neutrino dark matter in the cores of galaxies

2006 ◽  
Vol 458 (2) ◽  
pp. L9-L12 ◽  
Author(s):  
F. Munyaneza ◽  
P. L. Biermann
Keyword(s):  
Dark Matter ◽  
Sterile Neutrino

scholarly journals Sterile neutrino Dark Matter

2019 ◽  
Vol 104 ◽  
pp. 1-45 ◽  
Author(s):  
A. Boyarsky ◽  
M. Drewes ◽  
T. Lasserre ◽  
S. Mertens ◽  
O. Ruchayskiy
Keyword(s):  
Dark Matter ◽  
Sterile Neutrino

scholarly journals Annihilating dark matter search with 12 yr of Fermi LAT data in nearby galaxy clusters

2021 ◽  
Vol 502 (3) ◽  
pp. 4039-4047
Author(s):  
Charles Thorpe-Morgan ◽  
Denys Malyshev ◽  
Christoph-Alexander Stegen ◽  
Andrea Santangelo ◽  
Josef Jochum
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Gamma Ray ◽  
Nearby Galaxy ◽  
Galactic Latitude ◽  
Dark Matter Search ◽  
Dwarf Spheroidal Galaxies ◽  
Characteristic Signal ◽  
Small Factor ◽  
The Impact

ABSTRACT Galaxy clusters are the largest virialized objects in the Universe and, as such, have high dark matter (DM) concentrations. This abundance of dark matter makes them promising targets for indirect DM searches. Here we report the details of a search, utilizing almost 12 yr of Fermi/LAT data, for gamma-ray signatures from the pair annihilation of WIMP dark matter in the GeV energy band. From this, we present the constraints on the annihilation cross-section for the $b\overline{b}$, W+W−, and γγ channels, derived from the non-detection of a characteristic signal from five nearby, high Galactic latitude, galaxy clusters (Centaurus, Coma, Virgo, Perseus, and Fornax). We discuss the potential of a boost to the signal due to the presence of substructures in the DM haloes of selected objects, as well as the impact of uncertainties in DM profiles on the presented results. We assert that the obtained limits are, within a small factor, comparable to the best available limits of those based on Fermi/LAT observations of dwarf spheroidal galaxies.

scholarly journals Turnaround radius of galaxy clusters in N-body simulations

2020 ◽  
Vol 639 ◽  
pp. A122 ◽  
Author(s):  
Giorgos Korkidis ◽  
Vasiliki Pavlidou ◽  
Konstantinos Tassis ◽  
Evangelia Ntormousi ◽  
Theodore N. Tomaras ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Cosmological Parameters ◽  
Three Dimensional ◽  
Average Density ◽  
Matter Density ◽  
Tidal Forces ◽  
Spherical Collapse ◽  
Collapse Model ◽  
Model C

Aims. We use N-body simulations to examine whether a characteristic turnaround radius, as predicted from the spherical collapse model in a ΛCDM Universe, can be meaningfully identified for galaxy clusters in the presence of full three-dimensional effects. Methods. We use The Dark Sky Simulations and Illustris-TNG dark-matter-only cosmological runs to calculate radial velocity profiles around collapsed structures, extending out to many times the virial radius R200. There, the turnaround radius can be unambiguously identified as the largest nonexpanding scale around a center of gravity. Results. We find that: (a) a single turnaround scale can meaningfully describe strongly nonspherical structures. (b) For halos of masses M200 >  1013 M⊙, the turnaround radius Rta scales with the enclosed mass Mta as Mta1/3, as predicted by the spherical collapse model. (c) The deviation of Rta in simulated halos from the spherical collapse model prediction is relatively insensitive to halo asphericity. Rather, it is sensitive to the tidal forces due to massive neighbors when these are present. (d) Halos exhibit a characteristic average density within the turnaround scale. This characteristic density is dependent on cosmology and redshift. For the present cosmic epoch and for concordance cosmological parameters (Ωm ∼ 0.3; ΩΛ ∼ 0.7) turnaround structures exhibit a density contrast with the matter density of the background Universe of δ ∼ 11. Thus, Rta is equivalent to R11 – in a way that is analogous to defining the “virial” radius as R200 – with the advantage that R11 is shown in this work to correspond to a kinematically relevant scale in N-body simulations.

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