Evolution of the X-Ray Luminosity and Metallicity of Starburst Blown Superbubbles

Abstract

We calculate the time-dependent metal production expected from a starburst, and use it as a boundary condition in our 2D simulations of evolving superbubbles. It is assumed that the produced metals (namely oxygen and iron) thoroughly mix with the ejected stellar envelopes, and/or with the matter thermally evaporated from the superbubble cold outer shell. The process thus determines the time-dependent metallicity in the hot interior of superbubbles, and is shown to lead to values of Z ≥ Z _⊙ when oxygen is used as tracer, and undersolar when the metallicity is measured with respect to the iron content. Here we show that in either case, the enhanced metallicities boost the X-ray emissivity of superbubbles.