Strong-Lensing Analysis of Three X-ray Luminous Galaxy Clusters Imaged with the Hubble Space Telescope

by Mrs. Lipaz Aspir

BGU

at Astrophysics and Cosmology Seminar

Wed, 21 May 2025, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

We present a first strong gravitational lensing analysis of three X-ray luminous galaxy clusters at a redshift of z ≈ 0.25, recently imaged with the Hubble Space Telescope. We identify sets of multiply imaged galaxies behind each cluster, measure their redshift using spectroscopic data where possible, and use them as constraints for the modeling. The mass reconstruction is performed using a code that incorporates a flexible parametrization of the Dark Matter distribution, alongside the individual contributions from cluster member galaxies, to find a best-fit model for the total mass-distribution. The resulting models yield detailed maps of the projected mass distribution in each cluster, as well as magnification maps which can be used, for example, to study high-redshift lensed objects. We compare the lensing-derived mass maps to the X-ray morphology to qualitatively assess the dynamical state and substructure in each system. In course of study, we also identify an intriguing outflow from the central Bright Cluster Galaxy (BCG) in one of the clusters. Our results provide a glimpse into the internal structure of and can aid in studying the formation history of massive galaxy clusters, the most massive gravitationally bound structures in the Universe.

Created on 18-05-2025 by Zitrin, Adi (zitrin)
Updaded on 18-05-2025 by Zitrin, Adi (zitrin)