Version 2 (final). Wed Feb 27. 2:38 PM (EST). -801262292 Assigned ID: 1014 ----- Attempting Submission 1 (Thu Feb 14 19:25:27 GMT 2013) ----- HST Phase I Proposal 1014 (rryan_wisps.apt) successfully submitted. ----- Attempting Submission 2 (Wed Feb 27 19:38:15 GMT 2013) ----- We are the proposing largest, most comprehensive archival campaign with HST to identify and characterize distant brown dwarfs to date. By exploiting the unprecedented sensitivity and excellent field-of-view of the WFC3/IR detector, we expect to find ~110 M- and ~30 L-dwarfs out to heliocentric distances of >1000 pc (for an L8-dwarf), whereas current surveys are limited to <300 pc. Furthermore, by observing with an infrared grism that optimally samples the water absorption feature at 1.4 microns, we can easily distinguish our target sample from interloping objects. Therefore our sample will be >90% complete to J~24 and nearly 100% free of contaminating objects (such as giants, subdwarfs, or high-redshift quasars). We have four main science goals for these ultracool dwarfs: (1) Identify ultracool dwarfs from water absorption; (2) Measure the vertical scale height as a function of spectral type; (3) Characterize the atmospheric properties of distant ultracool-dwarfs; and (4) Search for rare T/Y transition dwarfs by complete water/methane and enhanced ammonia absorption. We plan to mine 0.5 square degrees of archival grism data in G141 taken by the pure-parallel (WISPS) and the Legacy (3d-HST) surveys. Our approach represents the most efficient means of surveying these low luminosity objects at kiloparsec distances with robust spectral types. COOL STARS Default Medium false false false false false SUPPORTED