| Description |
One of the most fundamental correlations between the properties of galaxies in the local Universe is the so-called morphology-density relation. In the local Universe late type star forming galaxies favor low density regimes and giant ellipticals reside in the cluster cores. Much of the debate centers on whether the relation arises early on during the formation of the object, or whether it is caused by environment-driven evolution. To shed ligth on this issue, we propose to map with PACS at 100 and 160 um the field of 8 clusters in the ..cluster desert. at 1.4 < z < 1.8, at the epoch when clusters are accreting galaxies and galaxies are still undergoing their own formation process. Our goal is to observe each system down to log(LIR)=11.5 to observe almost the entire LIRGs and the complete ULIRGs population and to sample the bulk of the star formation. The 8 systems are all X-ray detected, spectroscopically confirmed and with large amount of multi-wavelength ancillary data. The X-ray detection ensures that these are well established, bound structures, which represent the missing link between the protoclusters at z > 2 and the well formed clusters in the local Universe. Our sample spans almost a decade in X-ray luminosity and dynamical mass, comprising relatively young systems and already old and relaxed clusters. This hetereogenity allows us to link the level of star formation activity to the global properties of the systems to shed light on which environmental process, if any, can affect the galaxy star formation activity. All systems are covered by medium-deep and deep XMM and Chandra data, crucial to reveal X-ray faint AGNs, and to study the connection between AGN feedback and star formation activity. The availability of accurate stellar mass estimates allows to relate the SF activity to the environment in different mass bins, thus disentangling the mass- from the environment-driven galaxy evolution. |
