The Evolution of Disk Galaxies Since z=1
  Based on VLT/FORS spectroscopy and HST/ACS imaging, we have constructed a sample of ~200 field spiral galaxies that cover redshifts up to z~1. Such a large data set allows to study the evolution of fundamental galaxy parameters like luminosity, size, mass, mass-to-light ratio etc. as a function of cosmic time and in various mass regimes. Several of our findings - like the time-independent fraction of stellar-to-total mass - are in compliance with a hierarchical structure growth. However, the stellar population properties of intermediate-redshift disks favour a down-sizing scenario in the sense that the average stellar ages in high-mass spirals are older than in low-mass spirals. 
Asmus Boehm, Bodo L. Ziegler