The Evolution of Galaxy Dust Properties for 1<z<2.5
  Fundamental properties of the extinction curve, like the slope in the rest-frame UV and the presence/absence of a broad absorption excess centred at 2175A (the UV bump), are investigated for a sample of 108 massive, star-forming galaxies at 1<z<2.5, selected from the FDF Spectroscopic Survey, the K20 survey, and the GDDS. These characteristics are constrained from a parametric description of the UV spectral energy distribution of a galaxy. It turns out that the sample galaxies host dust producing extinction curves with properties in between those of the Small and Large Magellanic Clouds (SMC and LMC, respectively). LMC-like extinction curves, which exhibit a UV bump, are mainly found among highly-reddened, UV-ultraluminous galaxies at z~2.4 and highly-reddened, near-IR-bright, star-forming galaxies at z~1.2. We discuss star-formation rates, total stellar masses, the morphology, and the chemical properties of our sample galaxies with respect to possible explanations for the different extinction curves. 
Stefan Noll, Daniele Pierini, Maurilio Pannella, Sandra Savaglio (all   MPE)