The Nature of Low-surface-brightness Galaxies in the Hyper Suprime-Cam Survey

Abstract

Abstract We present the statistical redshift distribution of a large sample of low-surface-brightness (LSB) galaxies identified in the first 200 deg2 of the Hyper Suprime-Cam Strategic Survey Program. Through cross-correlation with the NASA–SDSS Atlas, we find that the majority of objects lie within z < 0.15 or ∼500 Mpc, yielding a mass range of M * ≈ 107−109 M ⊙ and a size range of r eff,g ≈ 1−8 kpc. We find a peak in the distance distribution within 100 Mpc, corresponding mostly to ∼107 M ⊙ galaxies that fall on the known mass–size relation. There is also a tail in the redshift distribution out to z ≈ 0.15, comprising more massive (M * = 108 − 109 M ⊙) galaxies at the larger end of our size range. We see tentative evidence that at the higher-mass end (M * > 108 M ⊙), the LSB galaxies do not form a smooth extension of the mass–size relation of higher-surface-brightness galaxies, perhaps suggesting that the LSB galaxy population is distinct in its formation path.