Evolution of Beryllium and Boron in the Inhomogeneous Early Galaxy
Abstract
A model of supernova-driven chemical evolution of the Galactic halo, recently proposed by Tsujimoto, Shigeyama, & Yoshii (1999, ApJL, 519, 64), is extended in order to investigate the evolution of light elements such as Be and B (BeB), which are produced mainly through spallative reactions with Galactic cosmic rays. In this model each supernova sweeps up the surrounding interstellar gas into a dense shell and directly enriches it with ejecta which consist of heavy elements produced in each Type II supernova with different progenitor masses. We propose a two-component source for GCRs such that both interstellar gas and fresh SN ejecta engulfed in the shell are accelerated by the shock wave. Our model results include: (1) a prediction of the intrinsic scatter in BeB and [Fe/H] abundances within the model, (2) a successful prediction of the observed linear trend between BeB and [Fe/H], (3) a proposal for using BeB as a cosmic clock, as an alternative to [Fe/H], and (4) a method for possibly constraining the BBN model from future observations of metal-poor stars.
Keywords
Cite
@article{arxiv.astro-ph/9907182,
title = {Evolution of Beryllium and Boron in the Inhomogeneous Early Galaxy},
author = {Takeru Ken Suzuki and Yuzuru Yoshii and Toshitaka Kajino},
journal= {arXiv preprint arXiv:astro-ph/9907182},
year = {2009}
}
Comments
3 color figures in 7 pages, accepted by ApJ Letters