No CrossRef data available.
Article contents
Chemical history at $z \ge 2.0$: first results from the Magellan+Keck survey of Lyman limit systems
Published online by Cambridge University Press: 06 October 2005
Abstract
We present a measurement of $\left[\rm{O}/\rm{Fe}\right]$ versus $\left[\rm{Fe}/\rm{H}\right]$ in the $z>2$ IGM derived from a sample of 23 Lyman Limit systems whose column density lies in the range $19.0\le\log N_{HI}\le 20.2$ cm$^{-2}$. The systems span a metallicity range of $-2.70 \le \left[\rm{Fe}/\rm{H}\right]\le -0.50$, allowing for a direct comparison with similar studies of stars within the Milky Way. Although the Lyman Limit systems can be highly ionised, the effects of ionisation on the determination of $\left[\rm{O}/\rm{Fe}\right]$ is minor for most of the systems in the sample. The data appear to show a decrease in $\left[\rm{O}/\rm{Fe}\right]$ with increasing metallicity with an approximate slope of $m\simeq-0.55$. We also determine a best fit power law slope of $\alpha=-1.86 \pm 0.2$ to the column density distribution $f_{HI}(N)$ for $19.0 \le\log N_{HI}\le 20.2$ cm$^{-2}$.
- Type
- Contributed Papers
- Information
- Proceedings of the International Astronomical Union , Volume 1 , Colloquium C199: Probing Galaxies through Quasar Absorption Lines , March 2005 , pp. 463 - 465
- Copyright
- © 2005 International Astronomical Union