Star formation history of early-type galaxies

We present studies over the star formation history (SFH) for different redshift ( 0.4 < z < 1.4) and stellar masses in the range between 7 < log(Mstar) < 12 [Msun] for early-type galaxies observed by the VIMOS Public Extragalactic Redshift Survey (VIPERS). VIPERS is an ongoing Large Programme to map in detail the large-scale distribution of galaxies at 0.5 < z < 1.2 with a unique volume (24 square deg) and sampling density. The final sample of this survey is going to reach nearly 100,000 galaxies. As the VIPERS sample contains ~15% of the early type galaxies with known spectroscopic redshift and good quality spectra, it is a perfect sample to study the star formation history based on the spectroscopic features.

We used the 4000 Å break strength Dn(4000) and Balmer absorption line strength HδA as diagnostics of the past formation histories of galaxies. These indicators provide important information about the ages of the stellar populations in galaxies and allow to reveal the character of recent star formation histories.