Modeling Increased Metal Production in Galaxy Clusters with
  Pair-Instability Supernovae
  Galaxy clusters contain much more metal per star, typically 3 times as much,
than is produced in normal galaxies. We set out to determine what changes are
needed to the stellar mass function and supernovae rates to account for this
excess metal. In particular, we vary the Type Ia supernovae rate, IMF slope,
upper and lower mass cutoffs, and the merger rate of massive stars. We then use
existing simulation results for metal production from AGB stars, Type Ia SNe
and core-collapse SNe to calculate the total amount of each element produced
per solar mass of star formation. For models with very massive stars, we also
include metal production from pair-instability supernovae (PISNe).We find that
including PISNe makes it much easier to increase the amount of metal produced
per stellar mass. Therefore a separate population of high-mass stars is not
needed to produce the high amounts of metal found in galaxy clusters. We also
find that including at least some PISNe increases the abundance of
intermediate-mass elements relative to both oxygen and iron, consistent with
observations of ICM abundances.
