Environmental dependence of galaxy age in the Main galaxy sample of SDSS   DR10
  Using two volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 10 (SDSS DR10), I investigate the environmental dependence of galaxy age, and get the same conclusions in two volume-limited Main galaxy samples: old galaxies exist preferentially in the densest regions of the universe, while young galaxies are located preferentially in low density regions. Such an age-density relation is likely a combination of a strong age-stellar mass relation and the stellar mass-density relation. 
Xin-Fa Deng
astro-ph.GA