| Description |
We propose to study the star formation history of galaxy
clusters in the -yet unexplored- redshift range of0.9-2.4,
at a time galaxy clusters were assembling galaxies
and local massive early-type galaxies were building up,
with deep PACS and SPIRE imaging on a sample of
8 high-redshift galaxy clusters and proto-clusters.
We will be in a position to confirm the increase
in the fraction of dusty star-forming cluster galaxies
found by Spitzer up to z=0.8 (the mid-IR Butcher-Oemler
effect) and extend it to z>1 for the first time, at wavelength
close to the peak of the spectral energy distribution
of star-forming galaxies.
Our sample includes clusters at different mass/richness
This will allow to understand the role and importance of
environment and the physical processes by which galaxy
clusters are accreting new galaxy falling from the outskirts
with high star formation rates.
This program promises to shed some new light too on the
assembly of the oldest galaxies at z=0 by combining the
clean and robust Herschel-derived SFRs (no assumptions
of SEDs) and a sample of clusters that covers a broad range
in mass, age and dynamical state at previously unexplored
redshifts for these wavelengths. |
