Mass and magnification maps for the Hubble Space Telescope Frontier Fields clusters: implications for high redshift studies

TL;DR

This paper presents detailed mass and magnification maps for six Hubble Frontier Fields clusters, enabling improved detection and study of high-redshift galaxies through gravitational lensing.

Contribution

It provides the first combined strong- and weak-lensing models for these clusters, calibrated with 88 multiple-image systems, to aid in high-redshift galaxy research.

Findings

Maps enable detection of galaxies at z>10 as faint as m(AB)=32.

Lensing boosts sensitivity, allowing observations 2 magnitudes deeper than the Hubble Ultra Deep Field.

Models serve as a community resource for future high-redshift studies.

Abstract

Extending over three Hubble Space Telescope (HST) cycles, the Hubble Frontier Fields (HFF) initiative constitutes the largest commitment ever of HST time to the exploration of the distant Universe via gravitational lensing by massive galaxy clusters. We here present models of the mass distribution in the six HFF cluster lenses, derived from a joint strong- and weak-lensing analysis anchored by a total of 88 multiple-image systems identified in existing HST data. The resulting maps of the projected mass distribution and of the gravitational magnification effectively calibrate the HFF clusters as gravitational telescopes. Allowing the computation of search areas in the source plane, these maps are provided to the community to facilitate the exploitation of forthcoming HFF data for quantitative studies of the gravitationally lensed population of background galaxies. Our models of the gravitational magnification afforded by the HFF clusters allow us to quantify the lensing-induced boost in sensitivity over blank-field observations and predict that galaxies at $z>10$ and as faint as m(AB)=32 will be detectable, up to 2 magnitudes fainter than the limit of the Hubble Ultra Deep Field.