HerMES Large Mode Survey: LARGE AREA SURVEY TARGETING LARGE-SCALE MODES

We propose a unique addition to the HerMES family of maps, the HerMES Large Mode Survey (HeLMS), which will be observed as part of the remaining SPIRE GT time. The field covers 270 deg2 with two repeats over roughly 106 hours. It is chosen to overlap the SDSS Stripe 82 in a region where the Galactic cirrus with a mean flux density of 1.2 MJy sr1 is at its lowest. The ancillary coverage in this field is extensive, particularly in the optical, making it an attractive large field. The scientific advantages of having a field with the size and makeup of HeLMS are twofold: first, the large survey area, of which 55 deg2 overlaps Stripe 82, will allow us to resolve approximately 250, 000 sources, of which 250 500 will be gravitationally lensed. Second, the large, uniform and crosslinked area will allow for unprecedented measurement of largescale modes (down to l 150). Such fidelity would be a unique asset in the submillimeter regime for the foreseeable future, and would enable crossfrequency correlation analysis with 80 deg2 of deep ACT maps, Planck over the full 270 deg2, as well as future observations with upcoming instruments like ALMA, ACTpol, and others. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]