The mass distribution of RX J1347-1145 from strong lensing

TL;DR

This study uses high-resolution imaging to identify multiple gravitational lensing images in galaxy cluster RX J1347-1145, enabling detailed mass mapping that aligns with but exceeds previous X-ray based estimates.

Contribution

It presents a new detailed mass map of RX J1347-1145 using strong lensing and a Markov chain Monte Carlo method, including newly identified multiple images.

Findings

Mass profile agrees with previous X-ray estimates

Lensing mass estimates are systematically higher than X-ray estimates

Identified multiple new lensing images in the cluster

Abstract

High resolution HST/ACS images of the galaxy cluster RX J1347-1145 have enabled us to identify several new multiple image candidates in the cluster, including a 5 image system with a central image. The multiple images allow us to construct an accurate 2-dimensional mass map of the central part of the cluster. The modelling of the cluster mass includes the most prominent cluster galaxies modelled as truncated isothermal spheres and a smooth halo component that is described with 2 parametric profiles. The mass reconstruction is done using a Markov chain Monte Carlo method that provides us with a total projected mass density as well as estimates for the parameters of interest and their respective errors. The mass profile is in reasonable agreement with previous mass estimates based on the X-ray emission from the hot intra-cluster gas, however the X-ray mass estimates are systematically lower than what we obtain with gravitational lensing.