Sulphur in the early ages of the galaxy

Abstract

We present here the results of the measurement of the sulphur abundance in very metal-poor stars. Our sample covers the [-4;-2] range of metallicity, and thus allows us to constraint the chemical evolution models and also to put some key constraints on the supernovae models. We measured the IR triplet of the sulphur, that is to say the following lines: 9212.863, 9228.093 and 9237.538. The abundance determination leads to the confirmation that sulphur behaves like an α element, and we can confirm that the [S/Fe] ratio reaches a plateau when the metallicity decreases and becomes lower than -2. The value of this plateau is close to 0,4 dex. © 2006 Springer-Verlag Berlin Heidelberg.