M81 in X-rays

At the highest energies for which we can resolve details in such a galaxy, its appearance changes radically. The mildly active nucleus now appears as the dominant central source, enormously brighter than the other sources. The additional X-ray sources are stellar, X-ray binary stars in which mass transfer onto a compact companion (neutron star or black hole) generates very high temperatures. The optics of ROSAT's X-ray telescope make these sources appear larger when farther from the field center; also apparent is the black circle and struts, due to shadowing by a support structure in the instrument. The field here is about twice as large as shown in the visible-light image.

These data were taken by the German-UK-US ROSAT satellite, and provided by the High-Energy Astrophysics Science Archive Research Center, NASA Goddard Space Flight Center.

M81 multiwavelength data | Messier gallery | Galaxies | Image gallery | UA Astronomy | Bill Keel's home page

Last changes: 5/2001      © 2001