X-ray and strong lensing mass estimate of MS2137.3-2353

TL;DR

This study combines X-ray and strong lensing analyses to accurately estimate the mass of galaxy cluster MS2137.3-2353, resolving previous discrepancies and providing insights into its mass distribution and density profile.

Contribution

The paper demonstrates that X-ray and strong lensing mass estimates can be reconciled for MS2137.3-2353 using detailed modeling, challenging earlier claims of significant discrepancies.

Findings

Good agreement between X-ray and lensing mass estimates

Estimated M_200 ~ 4.4 x 10^14 solar masses

No evidence for high concentration in NFW profile

Abstract

We present new mass estimates of the galaxy cluster MS2137.3-2353, inferred from X-ray and strong lensing analyses. This cluster exhibits an outstanding strong lensing configuration and indicates a well-relaxed dynamical state, being most suitable for a mass reconstruction which combines both techniques. Despite this, several previous studies have claimed a significant discrepancy between the X-ray and the strong lensing mass estimates. The primary aim of this paper is to address and explain this mismatch. For this purpose, we have analysed Chandra observations to recover the profiles of the intra-cluster medium properties and, assuming a functional form for the matter density, the total mass distribution. The notable strong-lensing features of MS2137.3 allow us to reconstruct its projected mass in the central regions with good accuracy, by taking advantage of the lensing inversion code Lenstool. We find a good agreement between our X-ray and strong lensing mass estimates for MS2137, leading to a mean, extrapolated value of M_200 ~ 4.4 +/- 0.3*10^14 M_sun, under the assumption of the Navarro-Frenk-White (NFW) density profile. However, the strong lensing mass estimate is affected by the details of the BCG mass modeling. In particular, we do not find evidence for a high concentration for the NFW density profile, as reported in some earlier works.