Cross, D;
Thoron, G;
Jeltema, TE;
Swart, A;
Hollowood, DL;
Adhikari, S;
Bocquet, S;
... Wiseman, P; + view all
(2024)
Examining the self-interaction of dark matter through central cluster galaxy offsets.
Monthly Notices of the Royal Astronomical Society
, 529
(1)
pp. 52-58.
10.1093/mnras/stae442.
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Abstract
While collisionless cold dark matter models have been largely successful in explaining a wide range of observational data, some tensions still exist, and it remains possible that dark matter possesses a non-negligible level of self-interactions. In this paper, we investigate a possible observable consequence of self-interacting dark matter: offsets between the central galaxy and the centre of mass of its parent halo. We examine 23 relaxed galaxy clusters in a redshift range of 0.1–0.3 drawn from clusters in the Dark Energy Survey and the Sloan Digital Sky Survey which have archival Chandra X-ray data of sufficient depth for centre and relaxation determination. We find that most clusters in our sample show non-zero offsets between the X-ray centre, taken to be the centroid within the cluster core, and the central galaxy position. All of the measured offsets are larger, typically by an order of magnitude, than the uncertainty in the X-ray position due to Poisson noise. In all but six clusters, the measured offsets are also larger than the estimated, combined astrometric uncertainties in the X-ray and optical positions. A more conservative cut on concentration to select relaxed clusters marginally reduces but does not eliminate the observed offset. With our more conservative sample, we find an estimated median X-ray to central galaxy offset of µ = 6.0+- 11 .. 45 kpc. Comparing to recent simulations, this distribution of offsets is consistent with some level of dark matter self-interaction, though further simulation work is needed to place constraints.
| Type: | Article |
|---|---|
| Title: | Examining the self-interaction of dark matter through central cluster galaxy offsets |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stae442 |
| Publisher version: | https://doi.org/10.1093/mnras/stae442 |
| Language: | English |
| Additional information: | © 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | galaxies: clusters: general, cosmology: dark matter, X-rays: galaxies: clusters |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10189093 |
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