PROBING THE ACCRETION HISTORIES OF LUMINOUS RED GALAXIES WITH HYPER SUPRIME-CAMERA SURVEY

Abstract

We use the Hyper Suprime-Camera (HSC) Survey to probe the stellar halos of luminous red galaxies (LRG). Our desire to measure the luminosity profile of stellar halos stems from the possibility that the slope of the stellar halo density is primarily shaped by the assembly history of the DM haloes. This leads to the presumption that the cosmological origin of stellar haloes, whose variable density distributions are the product of stellar stripping from accreted and merging satellites, is readily imprinted in the stellar halo density slope. As such, we characterize the slope of the luminosity density profiles of ~4,000 resolved galaxies by means of a power-law shape parameter αSTARS, estimated through a maximum likelihood approach (MLE). Our findings show that the LRG galaxy properties do not evolve as a function of αSTARS, consistent with our expectations. The candidate galaxies exhibit – 1.5 ≤ αSTARS ≤– 2.5, comprising a mean profile consistent with that of the Illustris galaxies in Pillepich et al. (2014). While processing the HSC data, we also investigate the possibility of photometric redshift contamination.