The chemical residue of a white dwarf-dominated galactic halo
BK Gibson, JR Mould
The Astrophysical Journal | Published : 1997
Halo initial mass functions (IMFs) heavily biased toward white dwarf (WD) precursors (i.e., ∼1-8 M⊙) have been suggested as a suitable mechanism for explaining microlensing statistics along the line of sight to the Large Magellanic Cloud. Such IMFs can apparently be invoked without violating the observed present-day WD luminosity function. By employing a simple chemical evolution argument, we demonstrate that reconciling the observed halo Population II dwarf abundances (i.e., [C, N/O] ≈ -0.5) with that expected from the postulated "WD-heavy" IMF (i.e., [C, N/O] ≳ +0.5) is difficult. © 1997. The American Astronomical Society. All rights reserved.