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11 May 2012

PISN at the Epoch of Reionization

Authors: Pan, Kasen, & Loeb
Link: here

This paper discusses the observability of PISN, Core Collapse, and Type Ia Supernovae with JWST. They use light curves and spectra of the explosions using a time dependent radiative transfer code for a wide range of Pop III stellar masses and evolutionary states. One key point they argue based on the luminosity of various explosions is that for detecting large numbers of PISN, a wide rather than deep survey will be better with JWST. In addition, spectra of the explosions will help determine the stellar progenitor and it's evolutionary state prior to the explosion.

After obtaining the spectra, they attempt to quantify how many SN are produced by using a very simple analytic argument for the SFR in the early universe. The SFR is calibrated to ensure the Universe is reionized by z=6. They have two classes of models: one where only Pop III stars reionize and one where only Pop II stars provide the reionizing photons. Two different IMF's are assumed (Salpeter and a flat IMF) for the Pop III stars, and a Salpeter IMF is used for the Pop II case. With this constraint, they make predictions for the detectability of PISN and CCSN, and find that it would be possible with JWST to distinguish between the two Pop III IMF models used here.

1 comment:

  1. The paper seemed to have a very simplistic model to form stars, especially as they seem to assume Pop III stars would still be forming down to z=6. How realistic is this (very strong) assumption?

    Also, it remains unclear as to what would be different in the case of joint Pop II and Pop III star formation.

    My overall feeling was that this paper addressed some very interesting questions, but the method was too simplistic to make very useful predictions.