Galaxy Distribution as a Probe of the Ringlike Dark Matter Structure in the Galaxy Cluster Cl0024+17

TL;DR

This study investigates whether the ringlike dark matter structure in galaxy cluster Cl0024+17 is reflected in the distribution of galaxies, finding no significant ring pattern in galaxy positions despite lensing evidence.

Contribution

The paper provides an analysis comparing galaxy distribution with dark matter structure, revealing the absence of the ringlike feature in galaxy positions.

Findings

Ringlike dark matter structure confirmed by lensing.

No corresponding ring pattern observed in galaxy distribution.

Galaxy positions do not show the dark matter ring at 3-sigma level.

Abstract

In a galaxy cluster, galaxies are mostly collisionless particles in recent epoches. They resemble collisionless cold dark matter particles in some way. Therefore, the spatial distributions of dark matter and cluster galaxies might be expected to possess similar features in the gravitational potential of a cluster. Here we use the galaxy distribution in cluster Cl0024+17 to probe for the ringlike dark matter structure recently discovered by means of strong and weak lensing observations. The galaxies are taken from the catalog of Czoske et al., which contains 650 objects with measured redshifts, of which ~300 galaxies have redshifts in the range 0.37<z<0.41 (and are therefore probable cluster members). We find that, at about the 3-sigma level, the ringlike structure seen in the dark matter measurement is not observed in the projected two-dimensional galaxy distribution.