X-Ray Polarization Near a Black Hole (IMAGE) Washington University in St. Louis Caption X-Calibur expects to find a 90 degree swing in the polarization of X-rays from the outer to the inner part of the accretion disk around a black hole. In this simulation of X-ray emission near a black hole, colors correspond to radiation intensity and the black bars indicate the X-ray polarization direction. The disk is viewed almost edge-on. The outer parts of the disk emit X-rays polarized parallel to the plane of the disk. Close to the black hole, the curvature of spacetime warps the photon trajectories, and photons returning to the disk lead to a net-polarization perpendicular to the plane of the disk. Because black holes and their accretion disks shrink as they rotate, the faster the black hole spins, the lower the energy at which the scientists expect to see the polarization swing. Credit NASA/Goddard Space Flight Center/Schnittman et al. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.