Polarized X-rays reveal shape, orientation of extremely hot matter around black hole

Researchers’ recent observations of a stellar-mass black hole called Cygnus X-1 reveal new details about the configuration of extremely hot matter in the region immediately surrounding the black hole. Matter is heated to millions of degrees as it is pulled toward a black hole. This hot matter glows in X-rays. Researchers are using measurements of the polarization of these X-rays to test and refine models that describe how black holes swallow matter, becoming some of the most luminous sources of light — including X-rays — in the universe.