Colloquia October 25 2012

On October 25, 2012 the astronomy department welcomed a guest from  Michigan State University.

Jay Strader is a MSU assistant professor in the fields of physics and astronomy.  He also completed

research at Santa Cruz.

During the Colloquia he focused his lecture on globular clusters and binaries. 

 

Globular clusters are very old, because of this all of the higher mass stars, that were originally found in the cluster, are all in their final stage of life.  In Globular clusters black holes behave irregularly. They do not behave the way we see them behave in less dense, more massive, galaxies. In globular clusters astronomers have discovered many black hole binaries. In these binaries two black holes orbit around each other. There have been between 100 and 1000 black holes discovered in globular clusters and many of them are in binary systems. It is estimated that there were at one time in history many more black holes but those black holes were ejected from the globular clusters. Astronomers believe that black holes are ejected when they try to join a already gravitationally bound two black hole binary. The third black hole is considered a “third wheel” and is sent flying off into space after the two black hole binary steals an extremely high amount of its energy. This process produces an immense amount of X-ray emission and it produces radio emission from the jets of matter that stream out from the top and bottom of the black holes.