The distribution of mass-to-light ratio in strong-lensing galaxy clusters

by Ms. Bar Zohar

BGU

at Astrophysics and Cosmology Seminar

Wed, 26 Oct 2022, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

The mass-to-light (M/L) ratio of massive structures, such as galaxy clusters, has played important historical roles: It highlighted “the missing mass problem” and the need for a dark matter component, as well as helped measure the matter content of the universe.
Recent campaigns of strong-lensing clusters with the Hubble Space Telescope now allow us to revisit – with higher resolution – the latest M/L estimates in cluster cores, which were previously mostly based on weak lensing.
In this talk I will present results from my Thesis, where we use publicly available lens models, along with Hubble imaging, to map the mass-to-light ratio (M/L) in 23 strong lensing galaxy clusters from the CLASH sample. We present the total projected M/L 2D maps and profiles and characterize the projected M/L ratio on various scales from substructures to the whole cluster core.
As may be expected, we find that the M/L increases with radius from a few in the cluster’s very center to ~a couple hundred at around 0.5 - 1 Mpc.
We also compare our results to the current state-of-the-art measurements made on stacked samples from weak-lensing analysis, and discuss the findings.

Created on 21-10-2022 by Zitrin, Adi (zitrin)
Updaded on 21-10-2022 by Zitrin, Adi (zitrin)