Published on Fri Mar 05 2021

Probing Intra-Halo Light with Galaxy Stacking in CIBER Images

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We study the stellar halos of galaxies with stellar masses spanning to (approximately galaxies at this redshift) using imaging data from the Cosmic Infrared Background Experiment (CIBER). A previous CIBER fluctuation analysis suggested that intra-halo light (IHL) contributes a significant portion of the near-infrared extragalactic background light (EBL), the integrated emission from all sources throughout cosmic history. In this work, we carry out a stacking analysis with a sample of 30,000 Sloan Digital Sky Survey (SDSS) photometric galaxies from CIBER images in two near-infrared bands (1.1 and 1.8 m) to directly probe the IHL associated with these galaxies. We stack galaxies in five sub-samples split by brightness, and detect an extended galaxy profile, beyond the instrument point spread function (PSF), derived by stacking stars. We jointly fit a model for the inherent galaxy light profile, plus large-scale one- and two-halo clustering to measure the extended galaxy IHL. We detect non-linear one-halo clustering in the 1.8 m band, at a level consistent with numerical simulations. Our results on the galaxy profile suggest that of the total galaxy light budget in our galaxy sample resides in the outskirts of the galaxies at kpc. We describe this extended emission as IHL and and are able to study how this fraction evolves with cosmic time. These results are new in the near-infrared wavelength at the mass scale, and suggest that IHL has a significant contribution to the integrated galactic light, and to the amplitude of large-scale background fluctuations.