Halo chemistry and first stars. The chemical composition of the matter in the early Galaxy, from C to Mg†
Abstract
From NLTE computations of the magnesium abundance in a sample of extremely metal-poor giants we derive [Mg/Fe]=+0.7, leading to [Al/Mg]=−0.80 and [Na/Mg]=−0.85 in the early Galaxy. The ratio [O/Mg] should be near to the solar value. Measurements of nitrogen abundances derived from the analysis of the NH band in eight more stars confirm the large scatter of the ratios [N/Fe] and [N/O] in the early Galaxy.
- Publication:
-
The Galaxy Disk in Cosmological Context
- Pub Date:
- March 2009
- DOI:
- 10.1017/S1743921308027804
- Bibcode:
- 2009IAUS..254..349S
- Keywords:
-
- Stars: abundances;
- stars: atmospheres;
- stars: Populations II;
- Galaxy:abundances;
- Galaxy:evolution;
- nucleosynthesis