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OATS-DAUT SEMINAR
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Speaker:
Dan Maoz (School of Physics and Astronomy, Tel-Aviv University)
Title:
Supernova Rates: Near and Far, Cluster and Field
Date: Wednesday, April 9th, 2008
Time: 12:00
Venue: Villa Bazzoni
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Abstract:
The measurement of supernova (SN) rates holds great promise,
both for tracing the history of cosmic metal enrichment and for
understanding the explosions themselves and their progenitors systems.
I will describe several ongoing observational programs to measure the
rates of type-Ia and core-collapse SNe, as a function of redshift and
environment. Based on measurements from the ground and with HST, the
SN-Ia rate in galaxy clusters remains low out to redshift z~1, arguing
for an early production of the large mass of intracluser metals by a
population with a short SN delay time. In the field, I will describe a
program with Subaru that aims to measure the SN rate out to z~2, using
novel methodologies for SN classification. First results suggest a SN-Ia
rate that may be tracking the star-formation history with a small delay,
in contrast to the conclusions of the HST-GOODS survey, but in accord
with expectations from recent local (z=0) results. Finally, I will
discuss a puzzling corollary of all the recent rate measurements: the
fraction of the supposed SN-Ia progenitor population that actually
explodes as SNe-Ia is suprisingly high -- perhaps higher than possible
in any of the currently popular models.
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contact: Elena Pian (OATS)