X-ray Polarimetry: A New Black Hole Probe

Tuesday, April 26, 2011 – 3:15pm
Reiss 502
Kevin Black
Goddard Space Flight Center, Greenbelt, Md

The polarization of X-rays emitted from black holes and neutron stars contains unique and important information about the structure of and processes in those extreme gravitational and magnetic environments. Yet, while astronomers have made extensive use of imaging, spectroscopy and photometry in the X-ray band, polarimetry remains unexploited, due to the poor sensitivity of previously available techniques. However, recent advances have produced X-ray polarimeters with orders-of-magnitude greater sensitivity, making astronomical polarimetry feasible even in the confines of a small observatory. I will discuss what we expect to learn from X-ray polarimetry, the experimental challenges that have frustrated us in the past, and the recent advances have that made polarimetry a practical reality. Finally, I will describe some concepts for polarimetery-based observatories, including NASA’s Gravity and Extreme Magnetism Small Explorer (GEMS), now in development at the Goddard Space Flight Center and scheduled for launch in 2014.

Host: Lydia Chiao-Yap