Enlarged Spleen Overview. The spleen is an important organ in the immune system. It is a bean shaped structure, located in the left upper portion of the abdominal cavity, under the diaphragm, tucked in between the 9th and 11th ribs, in the mid-back.
Chandra and NASA's Hubble Space Telescope later collected data from the event's afterglow, and together the observations led astronomers to conclude that the powerful explosions can result when a black hole and a neutron star collide, producing another black hole.
I am not sure if they are the coldest objects in the universe but they may be. Until mid-70es we thought that black holes can't emit any radiation, and thus do not have any effective temperature. Then Hawking realized that quantum vacuum fluctuations could lead to black holes emitting radiation(*).