Type: Talk
Session: Galaxy Morphology and Low Surface Brightness Features
Author: Lucia Paz Garate Nunez

Abstract: The intra-halo light (IHL) is the diffuse stellar component that surrounds galaxies, groups, and clusters. The IHL formation is intimately linked to the hierarchical assembly of the system and therefore provides us with deep insights into its evolution. However, the low surface brightness of the IHL makes it challenging to detect and also to distinguish from the point spread function (PSF) effect of the telescope. In this talk, I will present our innovative technique which corrects for the PSF-scattered light and estimates the IHL in astronomical images. I will show the results of applying this technique to estimate the IHL on a dozen of galaxy groups using deep data from the third data release of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP PDR3) and our extended HSC-SSP PDR3 PSF models (R∼5.6 arcmin). We demonstrate how the PSF-scattered light can overestimate the IHL fraction on a system by a factor of 30%. Due to the similarities in terms of depth, photometric bands and pipeline processing between HSC and LSST, our IHL estimation and PSF reconstruction methods will be directly applicable and beneficial to the LSST. During my presentation, I will show the kind of statistical IHL measurements we will be able to make over a significant range of group masses and redshifts with the upcoming LSST data.