Dr. Jeff Cookie (U. of California, Irvine)

Title: "The Detection of z ~ 2 Type IIn Supernovae in the CFHTLS Deep
Fields"

Abstract: Type IIn supernovae (SNe IIn) result from the deaths of the
most massive stars.  Their intrinsic luminosity and broad magnitude
distribution make these the most luminous SN events ever recorded
(brighter than Type Ia SNe).  Moreover, they are the most luminous SNe
in the rest-frame UV, making them ideal targets for high redshift
optical searches.  SNe IIn are defined by the extremely strong narrow
emission lines in their spectra as a result of the interaction between
the SN ejecta and circumstellar material released in pre-explosion
outbursts.  These emission lines remain strong for years after
outburst with many expected to be above the thresholds of current
8m-class telescope sensitivities out to z ~ 3.  The detection and
evolution of these lines can be used to confirm high redshift SNe and
measure their energies.  I will discuss our technique of detecting 0.8
< z < 2.2 SNe IIn in the CFHTLS Deep survey and present Keck host
galaxy spectroscopy that has confirmed the first two candidates at z =
0.8 and z = 2.0.  Finally, I will show evidence of the detection of
the SN emission lines in the spectra.  I will conclude with the
implications of the data on the high redshift SNe IIn supernova rate,
the galactic IMF, and address the potential of future deep surveys and
30m-class telescopes to detect and study SNe IIn to z ~ 6