Rotating massive stars: Pre-SN models and stellar yields at solar metallicity

Abstract

We present a new set of stellar yields obtained from rotating stellar models at solar metallicity covering the massive star range (9-120 solar masses). The stellar models were calculated with the latest version of the Geneva stellar evolution code described in Hirschi et al 2004a. The contributions from stellar winds and from supernova explosions to the stellar yields were calculated separately. The two contributions were then added to compute the total stellar yields (Hirschi et al 2004b). The effects of rotation on pre-supernova models are significant between 15 and 30 solar masses. Above 20 solar masses, rotation may change the radius or colour of the supernova progenitors (blue instead of red supergiant) and the supernova type (IIb or Ib instead of II). Rotation increases the helium and CO core sizes by a factor about 1.5. Thus, rotation increases the total metallic yields and in particular the yields for carbon and oxygen by a factor 1.5-2.5. For Wolf-Rayet stars (M>30 solar masses), rotation increases the yields of helium and other hydrogen burning products but does not significantly affect the yields of heavy elements.