出典:Wikipedia
出典:『Wikipedia』 (2011/06/09 18:35 UTC 版)
The Galactic ridge is a region of the inner galaxy that is coincident with the galactic plane of the Milky Way. This feature has a width of 5° latitude (b) and ±40° longitude (l) in the Galactic coordinate system. It is an intense source of X-ray emission known as the Galactic Ridge X-ray Emission (GRXE). Initially this emission was thought to be caused by low energy cosmic rays interacting with cold gas in the region, which heated up the gas and caused it to emit X-rays. However, it is now thought that about 80% of the emission comes from discrete sources such as white dwarfs and stars with active coronae.