The final fate of stars between ~1.0M☉ and ~7.0M☉ is an electron degenerate carbon-oxygen white dwarf (WD). These WD stars play a key role in stellar and galaxy evolution, as cosmological distance indicators, iron-group element factories, cosmic-ray accelerators, kinetic energy sources, and the terminus of stellar binary evolution. However, the thermonuclear reaction rates used in these models have compounded uncertainties that can affect the final characteristics of the white dwarf. While the reaction rates are derived from experiment when possible, some crucial reactions have yet to be reproduced experimentally at energies relevant for astrophysics. We investigate the sensitivity of the WD's structure and composition to the composite uncertainties in the nuclear reaction rates using the stellar evolution toolkit, Modules for Experiments in Stellar Astrophysics (MESA). A dense grid of stellar models is evolved from the pre-main sequence to the thermally pulsing asymptotic giant branch phase. We use a sophisticated nuclear reaction network that follows 49 isotopes from 1H to 34S with Monte Carlo sampled reaction rates from STARLIB to provide the first statistically rigorous study of the final characteristics of WDs.
American Astronomical Society Meeting Abstracts #227
- Pub Date:
- January 2016