On the Origin of Nitrogen in Damped Ly-alpha Systems
Astrophysics
2007-05-23 v1
Abstract
Recent measurements of nitrogen and alpha elements in over 20 damped Ly-alpha systems (DLA) are compared with similar measurements for numerous emission line objects and stars. It is found that the DLA distribution in the N/alpha-alpha/H plane is bimodal, where most sample DLAs fall along the N/alpha plateau defined at low Z by dwarf irregulars, while a small group possesses N/alpha values roughly 0.7 dex less than those on the plateau at similar alpha/H values. We demonstrate with chemical evolution models that a top-heavy or truncated IMF can account for the low N in this second group.
Keywords
Cite
@article{arxiv.astro-ph/0211512,
title = {On the Origin of Nitrogen in Damped Ly-alpha Systems},
author = {R. B. C. Henry and Jason X. Prochaska},
journal= {arXiv preprint arXiv:astro-ph/0211512},
year = {2007}
}
Comments
7 pages, in ``CNO in the Universe,'' ASP Conference Series, in press edited by C. Charbonnel, D. Schaerer, and G. Meynet