Abstract

Wolf-Rayet Stars and Dust Formation in the Early Universe

Anthony Moffat (Univ. de Montreal)

Sergey Marchenko, Science Systems and Applications, Inc., Lanham, Maryland, USA

Population-I Wolf-Rayet (WR) stars emerge at the latest evolutionary stages of massive (M_i >~ 25 M_sun) stars. Among various WR subgroups, some of the carbon-rich WC stars exhibit strong IR excesses linked to the formation of copious amounts, up to 10-6 M_sun/year, of carbonaceous dust. In the early Universe, over the first billion years, such prodigious WC dust-making stars should appear and may generate up to ~20% of the primordial dust necessary to form planets and lead to life. We show that, once formed, a significant fraction of the WC dust survives the harsh WR environment. Even more surprisingly, we find some traces of polycyclic aromatic hydrocarbons in the WC dust ejecta. This raises the possibility of a very early accumulation of complex pre-organic ingredients. JWST would be a powerful tool to probe such dust machines in the local Universe and beyond.

Mode of presentation: poster