SAO: Colliding Galaxy Clusters
Posted: Mon Dec 05, 2016 4:45 pm
Colliding Galaxy Clusters
Smithsonian Astrophysical Observatory
Weekly Science Update | 2016 Dec 02
A Spectacular Bow Shock in the 11 keV Galaxy Cluster Around 3C 438 - Deanna L. Emery et al
Smithsonian Astrophysical Observatory
Weekly Science Update | 2016 Dec 02
[img3="The galaxy 3C438 and its cluster of galaxies as seen in the optical (left) and in X-rays by the Chandra X-ray Observatory (right). Astronomers have concluded that the hot gas is the result of a collision between two clusters of galaxies.Galaxy clusters contain a few to thousands of galaxies and are the largest bound structures in the Universe. Most galaxies are members of a cluster. Our Milky Way, for example, is a member of the "Local Group," a set of about fifty galaxies whose other large member is the Andromeda galaxy. The closest large cluster of galaxies to us, about fifty million light-years away, is the Virgo Cluster, with about 2000 members.
X-ray: NASA/CXC/CfA/R.P.Kraft; Optical: Pal.Obs. DSS"]https://www.cfa.harvard.edu/sites/www.c ... 201647.jpg[/img3][hr][/hr]
Clusters are believed to grow as the result of mergers between smaller galaxy groups and from the accretion of gas and dark matter. The energy released in these mergers is largely dissipated in the hot gas within the cluster, where X-ray observations can spot evidence for shocks and high temperatures. Mergers between two equally massive galaxy clusters provide particularly important diagnostics since these energetic collisions have the most dramatic and long-lasting effects. These major mergers are relatively rare events, however. The Bullet Cluster is one recently analyzed example, and because it also happens to act as a gravitational lens for background galaxies, it became famous for showing the distribution of its dark matter. ...
A Spectacular Bow Shock in the 11 keV Galaxy Cluster Around 3C 438 - Deanna L. Emery et al
- arXiv.org > astro-ph > arXiv:1611.03489 > 10 Nov 2016