The Deepest Supernova Search is Realized in the Hubble Ultra Deep Field Survey

The Hubble Ultra Deep Field Survey has not only provided the deepest opticaland near infrared views of universe, but has enabled a search for the mostdistant supernovae to z~2.2. We have found four supernovae by searching spansof integrations of the Ultra Deep Field and the Ultra Deep Field Parallelstaken with the Hubble Space Telescope paired with the Advanced Camera forSurveys and the Near Infrared Multi Object Spectrometer. Interestingly, none ofthese supernovae were at z>1.4, despite the substantially increased sensitivityper unit area to such objects over the Great Observatories Origins Deep Survey.We present the optical photometric data for the four supernovae. We also showthat the low frequency of Type Ia supernovae observed at z>1.4 is statisticallyconsistent with current estimates of the global star formation history combinedwith the non-trivial assembly time of SN Ia progenitors.Comment: 24 pages (6 figures), submitted to the Astronomical Journa