NGC 4258 is a spiral galaxy about 25 million light years from Earth, also known as M106.
The Chandra image of NGC 4258 reveals the so-called anomalous arms. These mysterious structures are due to shock waves generated by the supermassive black hole in the nucleus of the galaxy.
Image credit: NASA/CXC/Univ. of Maryland/A.S. Wilson et al. larger image
