Constraining the Inner Dark Matter Profiles of Strong-Lensing Galaxy Clusters

Abstract

We present mass modeling of three strong lensing galaxy clusters found in the Dark Energy Survey utilizing Hubble Space Telescope imaging for lens modeling, and complementary constraints from Chandra X-ray observations. All three clusters are relaxed and have giant arc or ring lens structures ideal for constraints on the dark matter distribution. The strong lens modeling and X-ray temperatures yield consistent total cluster mass estimates. We find these clusters have best-fit X-ray temperatures of $2.7 - 6.2$ keV and total masses of M$_{200} = (1-6) \times 10^{14} M_{\odot}$. Our lens models parameterize dark matter distribution with a generalized Navarro-Frenk-White (GNFW) density profile. While the GNFW profile allows the inner dark matter slope to vary, we find in all cases that the inner slopes are consistent with the standard NFW density profile $γ^{DM} = 1$. The X-ray surface brightness distributions for all three clusters are generally symmetric with no significant substructure, supporting the conclusion that these are relaxed clusters. In addition, we find generally low values of the external shear magnitude with median values ranging $|γ^{ext}| = 0.04-0.09$ and consistent with zero for two of the clusters.