The Dirt on Cosmic Dust: An X-ray Perspective through Black Hole and Neutron Star Eyes

I will discuss how the combination of experimental programs at synchrotron beam-lines and high spectral resolution X-ray studies of compact objects (e.g. black holes and neutron stars), can be used as a powerful new tool for revealing new information about cosmic dust. I will discuss the viability for this work in the context of extant (e.g Chandra and XMM-Newton) and near-future missions (e.g. Astro-H), and our efforts to provide supporting laboratory data. Using a Galactic black hole as the primary example, I will also show how X-ray absorption studies can reveal the element-specific quantity and composition of dust and discuss implications for formation scenarios based on the dust found. Further, I will discuss how X-rays may be key to revealing a thus far missing population of grains. Time-permitting, I will show how accurate composition information can then be combined with X-ray (imaging) scattering halo studies to determine high precision distances, in one case, comparable to parallax measurements.