Stellar Disk Truncations at High z : Probing Inside-Out Galaxy Formation

Abstract

We have conducted a systematic search for stellar disk truncations in disk-like galaxies at intermediate redshift (z<1.1) using the Hubble Ultra Deep Field (UDF) data. We use the position of the truncation as a direct estimator of the size of the stellar disk. After accounting for the surface brightness evolution of the galaxies, our results suggest that the radial position of the truncations has increased with cosmic time by ~1-3 kpc in the last ~8 Gyr. This result indicates a small to moderate (~25%) inside-out growth of the disk galaxies since z~1.