| Description |
In the past week, the Wide-field Infrared Survey Explorer (WISE),has completed its first coverage of the entire sky at 3.4, 4.6, 12 and 22 microns (W1, W2, W3, and W4), reaching sensitivities hundreds of times deeper than IRAS. Also in the past week, we have obtained spectroscopy of over 50 WISE sources with unusual colors, including 14 with z > 1.8. Nine of these 14 sources were selected by requiring strong W4 detection combined with insignificant W1 and W2 detection: W1/W2 drops. After rejecting optically bright W1/W2 drops, only 4 sources at z < 1.8 are present. These sources have in excess of 1E13 solar luminosities, and possibly 1E15. We request 64.1 hours of Herschel time to observe a sample of 88 W1/W2 drops, augmented by 5 other WISE sources at z > 1.8, from 70 to 500 microns with PACS and SPIRE. The resulting SEDs will enable us to extend the obscurations, luminosities, and star formation rates associated with ultra-luminous infrared galaxies (ULIRGs) into uncharted terrain. |
