The Role of Environment on the Formation of Early-Type Galaxies

Understand

(Abridged) We present a detailed study of the stellar populations of a volume-limited sample of early-type galaxies from SDSS, across a range of environments -- defined as the mass of the host dark matter halo.

• The stellar populations are explored through the SDSS spectra, via projection onto a set of two spectral vectors determined from Principal Component Analysis.
• We find the velocity dispersion of the galaxy to be the main driver behind the different star formation histories of early-type galaxies.
• However, environmental effects are seen to play a role (although minor).