X-ray Astrophysics Laboratory
Astrophysics Science Division - X-ray Astrophysics Research

Eta Carina

Eta Carina

Extremely massive stars play a key role in chemical enrichment and galactic evolution. They mark the end of their lives as supernovae explosions in which a single supernova can equal the entire radiant output of a galaxy, and are the progenitors of stellar mass black holes of the type seen in X-ray binary systems and as LIGO mergers. Our understanding of the path by which a massive star becomes a black hole depends strongly on the mass loss and angular momentum history of the star, and our knowledge of this is very uncertain. Massive binaries are particularly important binary systems that allow for complex modes of mass exchange and loss. In non-compact massive binaries, X-ray emission is produced where the stellar wind from one of the stars collides with the stellar wind of the companion. These colliding wind binaries produce a line-rich thermal spectrum up to a few keV which serves as a local diagnostic of the mass-loss process in these systems. Our group has made detailed timing and X-ray spectral studies of a number of important massive colliding wind binaries, including the enigmatic, unstable, long period, highly eccentric system eta Carinae (the most luminous stellar system within 3 kpc), HD 193793 = WR 140, a similarly long-period system with high eccentricity which produces carbon-rich dust near periastron passage, gamma 2 Velorum (one of the nearest massive binaries) V444 Cygni, and other X-ray bright, non-compact, massive binaries.

Current Group Members