Individual stellar haloes of massive galaxies measured to 100 kpc at 0.3 < z < 0.5 using Hyper Suprime-Cam
Year: 2017
Type: article
Abstract: Massive galaxies display extended light profiles that can reach several hundreds of kilo parsecs. These stellar halos provide a fossil record of galaxy assembly histories. Using data that is both wide (~100 square degree) and deep (i>28.5 mag/arcsec^2 in i-band), we present a systematic study of the stellar halos of a sample of more than 3000 galaxies at 0.3 < z < 0.5 with $\log M_{\star}/M_{\odot} > 11.4$. Our study is based on high-quality (0.6 arcsec seeing) imaging data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP), which enables us to individually estimate surface mass density profiles to 100 kpc without stacking. As in previous work, we find that more massive galaxies exhibit more extended outer profiles. When this extended light is not properly accounted for as a result of shallow imaging or inadequate profile modeling, the derived stellar mass function can be significantly underestimated at the highest masses. Across our sample, the ellipticity of outer light profiles increases substantially as we probe larger radii. We show for the first time that these ellipticity gradients steepen dramatically as a function of galaxy mass, but we detect no mass-dependence in outer color gradients. Our results support the two-phase formation scenario for massive galaxies in which outer envelopes are built up at late times from a series of merging events. We provide surface mass surface mass density profiles in a convenient tabulated format to facilitate comparisons with predictions from numerical simulations of galaxy formation.
Institutions: Kavli Institute for the Physics and Mathematics of the Universe, University of California, Santa Cruz, The University of Tokyo Institutes for Advanced Study, University of California Observatories, Princeton University, Institute of Astronomy and Astrophysics, Academia Sinica, National Astronomical Observatory of Japan, Academia Sinica, The Graduate University for Advanced Studies, SOKENDAI
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Yale University, Vanderbilt University, Princeton University, Ohio State University, University of Washington, Johns Hopkins University, University of Portsmouth, New Mexico State University, Space Telescope Science Institute, York University, Queen's University Belfast, Durham University, Ministry of Education, Culture, Sports, Science and Technology, Academia Sinica, Cabinet Office, Government of Japan, National Central University, National Astronomical Observatory of Japan, High Energy Accelerator Research Organization, Eötvös Loránd Tudományegyetem, Max-Planck-Institut für Astronomie, Toray Science Foundation, College of Engineering, Michigan State University, Smithsonian Astrophysical Observatory, Science Mission Directorate, Japan Society for the Promotion of Science, Japan Science and Technology Agency, Planetary Science Division, Brookhaven National Laboratory, Lawrence Berkeley National Laboratory
Awards: G258938352, G4474636675, Collaborative Research: Connecting the Smallest and the Largest Galaxies to their Dark Matter Halos, G618131832, G6684161710, A NEO SEARCH PROGRAM USING THE PAN-STARRS PS1 TELESCOPETHE GOAL OF THE PROPOSED RESEARCH IS TO USE T, G7187964967, Pan-STARRS1: Operations; Public Data Release; Education and Outreach, G7950275392, G833430883
OpenAlex ID: W2730169491