The Herschel Proto-cluster Survey: SPIRE Mapping of the Nodes of the Cosmic Web at z>2

We propose an experiment to search for signatures of rapid growth of galaxies and AGNs in a sample of three z>2 protoclusters. These environments are exceptionally rare, previrialised regions corresponding to peaks in the matter density field, located at the nodes of largescale (>10Mpc) filamentary structures. They are the best candidates for the progenitors of the most massive clusters of galaxies (virgul10^15Msun) today. We pay special attention to an unusual class of object, preferentially located in protoclusters: Lyman alpha blobs (LABs) 100kpc scale luminous emissionline gas nebulae. Some LABs show signatures of recent galaxygalaxy mergers/interactions, are often host to luminous continuum sources, and many have evidence of gas inflows/outflows in their emissionline morphology. A significant fraction of LABs have embedded galaxies detected at Xray, midinfrared, and/or submm wavelengths, suggesting possible rapid growths of the galaxies and AGNs in protocluster regions. Are the protocluster systems more obscured than galaxies in the field? Are the protocluster systems growing more rapidly? By mapping these protoclusters with SPIRE, we will: (1) measure SFRs in submm (restframe FIR) for the galaxies and AGNs in the protoclusters, and determine how much star formation is obscured (when compared to UV estimate) and (2) determine SSFRs for the galaxies and AGNs in the protoclusters, and see how they compare to field galaxies at z23. This program will deliver fundamental information on the growth of galaxies and supermassive black holes in the densest regions of the Universe at highredshift, and provide valuable insight into the astrophysical processes that establish the trends linking galaxy properties and their environments. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]