Jeremy Ritter

 Theoretical “First Stars”, not observed  Formed from primordial Hydrogen and Helium  Zero metallicity  Studying chemical enrichment from first stars can give us information about the universe today  Calculate the time required to enrich primordial gas to solar metallicity Motivations

 Pop III IMF has peaks around 1 Msun and 100 Msun  Most of the mass in first clusters was in massive stars (>100 Msun) Buzzoni  Massive stars live short lives, only about a million years Nakamura, et al. 2001

 M < 9 Msun White Dwarf  9 < M < 25 Msun Neutron Star  25 < M < 140 Msun Black Hole  140 < M < 260 Msun Pair Instability Supernovae(PISN)  yield 50% of initial mass as metals Heger, et al. 2003

 Massive (> 100 Msun) Pop III stars were more common than intermediate mass stars  PISNe contribute a larger percentage of their initial mass as metals than do BHs, neutron stars, or white dwarfs  The most significant contribution to early chemical enrichment by Pop III stars was from massive stars exploding as PISN

 Simulate clusters of massive stars exploding and enriching the IGM  Study the timescale and type of mixing that occurs between the interacting shockwaves  Future research will include subsequent rounds of enriched star formation and supernovae.

 Buzzoni, A. 2002, ApJ 123, 1188  Heger, A., Fryer, C., Woosley, S., Langer, N., Hartmann, D. 2003, ApJ 591, 288  Nakamura, F. & Umemura, M. 2001, ApJ 548, 19