The Giant Bird Galaxy Cluster

Using the European Southern Observatory's Very Large Telescope in Chile's Atacama Desert, an international team of astronomers has discovered a stunning rare case of a triple merger of galaxies. This system, which astronomers have dubbed 'The Bird' - albeit it also bears resemblance with a cosmic Tinker Bell - is composed of two massive spiral galaxies and a third irregular galaxy, with the 'head' being the third component, and the 'heart' and 'body' making the two major galaxy nuclei in-between of tidal tails, the 'wings'. The latter extend more than 100,000 light-years, or the size of our own Milky Way.

The galaxy ESO 593-IG 008 was previously merely known as an interacting pair of galaxies at a distance of 650 million light-years. Underneath the chaotic appearance of the optical Hubble images - retrieved from the Hubble Space Telescope archive - the images show two unmistakable galaxies, one a barred spiral while the other is more irregular.

The surprise lay in the clear identification of a third, clearly separate component, an irregular, yet fairly massive galaxy that seems to be forming stars at a frantic rate.

"Examples of mergers of three galaxies of roughly similar sizes are rare," says Petri Väisänen, lead author of the paper reporting the results. "Only the near-infrared VLT observations made it possible to identify the triple merger nature of the system in this case."

Posted by Casey Kazan.

Story Link:

http://www.eso.org/public/outreach/press-rel/pr-2007/pr-55-07.html