Synthesis of Heavy Elements in the Early Universe
Ian Roederer, Carnegie Observatories
What is the origin of the atoms around us? The steady and sometimes spectacular lifecycles of countless generations of stars have forged all elements on the periodic table from humble beginnings: nothing more than hydrogen and helium left over from the Big Bang. New details of this remarkable transformation continue to reveal unexpected surprises about the timing and nature of heavy element production. I will summarize the basic techniques astronomers use to study the compositions of other stars. I will show an example of how this "fossil record" is useful to understand how our Galaxy was assembled. I will sketch our current understanding of the physical processes that stars use to produce heavy elements. But we still lack confirmation that any of the proposed production sites is capable of producing elements as heavy as uranium. Further, there are some elements that have never been detected in any star useful for probing the fossil record. Ultraviolet spectroscopy of stars enabled by the Hubble Space Telescope continues to push the frontier of detection (and understanding may, slowly, follow), and I will highlight a few of these recent success stories. I will conclude with one vision for the future of this work that relies on the next generation of ultraviolet telescopes in space.