The Frontier Fields in 3D: Lens Modeling Abell 370 (and more) with Hubble and MUSE
Intervenant : David Lagattuta
CRAL - Lyon
By probing the build-up and formation of matter from small to large scales, we gain critical insight into many astrophysical phenomena, such as galaxy evolution, cosmology, and even the nature of dark matter itself. While many objects can be used to investigate the structure of matter, galaxy clusters act as ideal laboratories for these purposes, as they provide information at several physical scales and a wide range of mass environments simultaneously. Of the numerous techniques used to study cluster mass distributions, gravitational lensing remains one of the most robust methods, since it does not rely on kinematic tracers or make assumptions about the dynamic state of matter. In this talk, I will summarize my recent work modeling the strong-lensing cluster Abell 370 (A370) -- one of the six Hubble Frontier Fields -- using a combination of high-resolution Hubble Space Telescope (HST) imaging and MUSE Integral Field Unit (IFU) spectroscopy. Building on previous efforts, the IFU data significantly improves the lensing analysis, identifying over 20 new multiply-imaged systems, more than 200 cluster members, and a distribution of galaxies in the foreground and background, providing a robust three-dimensional picture of the A370 field. By combining the IFU and lens modeling data, we find evidence of additional mass (sub)structures along the line of sight and within the cluster plane, learning much about this complex system in the process. However, A370 is only the beginning of the story, and at the end of the talk I will lay out plans for an expanded HST+MUSE survey (named BUFFALO-WINGS) targeting the full set of Frontier Fields, in order to expand our understanding of mass distribution throughout the universe.