Jacob Hummel, Andreas Pawlik, Milos Milosavljevic, Volker Bromm
Theoretical models predict the supernova explosions ending the lives of some
of the first stars to have been extremely energetic pair-instability supernovae
(PISNe). With energies approaching 10^53 ergs, these supernovae are expected to
be within the detection limits of the upcoming James Webb Space Telescope
(JWST), allowing observational constraints to be placed on the properties of
the first stars. We estimate the source density of PISNe using a semi-analytic
halo mass function based approach, accounting for the effects of feedback from
star formation on the PISN rate using cosmological simulations. We estimate an
upper limit of ~2 PISNe per JWST field of view at any given time. Feedback can
reduce this rate significantly, e.g., lowering it to approximately one PISN
visible per 2.5 JWST fields of view. We also find that the main obstacle to
observing PISNe from the first stars is their scarcity, not their faintness;
exposures longer than a few times 10^4 s will do little to increase the number
of PISNe found. Given this we suggest a mosaic style search strategy for
detecting PISNe from the first stars as even rather high redshift PISNe are
unlikely to be missed by moderate exposures, and a large number of pointings
will be required to ensure a detection. For an observing program totalling 10^6
s, the probability of a detection is maximized by dividing the campaign into
~150 individual fields with ~5000 s exposure in each.
View original:
http://arxiv.org/abs/1112.5207
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