NGC 4631

The edge-on spiral NGC 4631 in optical (Green), UV (blue), and X-ray (Red). The X-ray image from a Chandra ACIS observation maps out a hot gaseous corona of the galaxy, whereas FUV emission comes from massive stars and the hydrogen line emission traces the warm ionized gas in the galaxy's disk. The picture clearly shows galactic disk/halo interaction, and presents probably the strongest evidence for the presence of galactic corona around a spiral galaxy.