Evolution of stellar disk truncations since z=1

TL;DR

This study investigates how the outer edges of disk galaxies have evolved since redshift 1, revealing a modest outward shift in the break radius and insights into star formation and redistribution processes over the last 8 billion years.

Contribution

It provides new observational evidence on the evolution of disk galaxy truncations and their color gradients, supporting inside-out galaxy formation models.

Findings

The break radius has increased by a factor of 1.3+-0.1 since z~1.

Radial color gradients show inside-out bluing at all redshifts.

Stars are formed inside the break and redistributed outward over time.

Abstract

We present our recent results on the cosmic evolution of the outskirst of disk galaxies. In particular we focus on disk-like galaxies with stellar disk truncations. Using UDF, GOODS and SDSS data we show how the position of the break (i.e. a direct estimator of the size of the stellar disk) evolves with time since z~1. Our findings agree with an evolution on the radial position of the break by a factor of 1.3+-0.1 in the last 8 Gyr for galaxies with similar stellar masses. We also present radial color gradients and how they evolve with time. At all redshift we find a radial inside-out bluing reaching a minimum at the position of the break radius, this minimum is followed by a reddening outwards. Our results constraint several galaxy disk formation models and favour a scenario where stars are formed inside the break radius and are relocated in the outskirts of galaxies through secular processes.