NGC 4631

The Walgalaxie or NGC 4631, sometimes herring galaxy is a spiral galaxy at a distance of about 25 million light years from Earth. She is seen in the direction of the Canes Venatici on the northern night sky from the side. The Walgalaxie is about the size of our Milky Way, and was discovered on 20 March 1787 by William Herschel. Their apparent visual magnitude is 9.0 like their angular size 15.5 ' x 2.7 '. The small neighboring galaxy NGC 4627 provides a certain deformation of the Walgalaxie. In addition, it seems in the past, often in the vicinity of the neighboring galaxy NGC to have come 4656/57, which still bear witness to hydrogen gas and other residues that are located between the two galaxies.

Of particular interest is the halo of hot gas surrounding the galaxy and extends up to a distance of 25,000 light years from the galactic plane. From research satellites Chandra high-resolution images of the X-ray emission of the halo were recovered. It is believed that the Milky Way is surrounded by a halo -like.