We investigate redshift evolution of the relation between stellar mass, and star formation history for a high quality sample of early-type galaxies (ETGs) observed by the VIMOS Public Extragalactic Redshift Survey (VIPERS). Among nearly 100,000 VIPERS targets more than 22% are ETGs, which makes it a perfect sample to study the star, formation history based on galaxy spectroscopic features. We use two stellar absorption line indices, the 4000 angstrom break strength, and the Balmer absorption line index H delta(A) as the indicators of the present and past star formation in galaxies, and measure their dependence of the stellar mass. We find that the age of stellar population changes both with stellar mass and redshift. Lower mass ETGs have younger stellar populations than galaxies with higher mass. This trend is preserved in all the redshift range 0.4 < z < 1.2 and it is similar to the trends observed in the local Universe. For all stellar mass ranges D-4000 increases with redshift, while H delta(A) gets lower, which can be interpreted as the confirmation of the "downsizing" scenario.
VIPERS view of the star formation history of early-type galaxies
Branchini, E.;
2015-01-01
Abstract
We investigate redshift evolution of the relation between stellar mass, and star formation history for a high quality sample of early-type galaxies (ETGs) observed by the VIMOS Public Extragalactic Redshift Survey (VIPERS). Among nearly 100,000 VIPERS targets more than 22% are ETGs, which makes it a perfect sample to study the star, formation history based on galaxy spectroscopic features. We use two stellar absorption line indices, the 4000 angstrom break strength, and the Balmer absorption line index H delta(A) as the indicators of the present and past star formation in galaxies, and measure their dependence of the stellar mass. We find that the age of stellar population changes both with stellar mass and redshift. Lower mass ETGs have younger stellar populations than galaxies with higher mass. This trend is preserved in all the redshift range 0.4 < z < 1.2 and it is similar to the trends observed in the local Universe. For all stellar mass ranges D-4000 increases with redshift, while H delta(A) gets lower, which can be interpreted as the confirmation of the "downsizing" scenario.
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