NASA has just granted fundings to a project to chase some of the most exotic astronomical prey: Black holes. A future spacetelescope will be able to study the polarisation of X-rays emitted from the matter falling into black holes

Henric Krawczynski, PhD, professor of physics at Washington University in St. Louis will be doing it with an instrument Jules Verne would appreciate, a balloon-borne telescope sensitive to the polarization of light that will float at an altitude of 130,000 feet for a day. During that time, the balloon will stare fixedly at two black holes in our galaxy, an extragalactic black hole, an accreting neutron star, the Crab nebula, and other targets yet to be chosen.

Called X-Calibur, the instrument, which is sensitive to “hard” X-rays with energies between 20 000 and 60 000 electron volts, is scheduled to go up in the spring 2013 or fall 2014. It will be flown at roughly the same time as another mission, GEMS, a satellite-borne instrument sensitive to “soft” X-rays, with energies between 2 000 and 10 000 electron volts. For comparison, visible light has energies between 2 and 3 electrons volts.

Krawczynski leads the X-Calibur experiment, whose development was sponsored by the McDonnell Center for the Space Sciences at Washington University. Krawczynski is a science collaborator on the GEMS experiment, which is led by Jean Swank, PhD, of the Goddard Space Flight Center.

To date, astronomers have measured X-ray polarization from only one astronomical source outside the solar system, the Crab Nebula, a supernova remnant in the constellation Taurus. GEMS is two orders of magnitude more sensitive than the instrument that looked at the Crab. X-Calibur extends the energy coverage into the hard X-ray regime, Krawczynski says.

Source: University of Washington