okt 052013

October 5, 2013

IRAS 23436+5257, a distorted galaxy in Cassiopeia

IRAS 23436+5257, a distorted galaxy in Cassiopeia

Image Credit: Judy Schmidt,  ESA, Hubble and NASA

IRAS 23436+5257 is a bright distorted galaxy in the northern constellation of Cassiopeia, which is named after an arrogant, vain, and yet beautiful queen in Greek mythology. It is speeding away from us at about 10,233 kilometers per second!

This galaxy’s worm-like structure and faint, sweeping stream of stars are most likely the result of a collision and subsequent merger of two galaxies. Such interactions are quite common in the Universe, and they can range from minor interactions involving a satellite galaxy being caught by a spiral arm, to major galactic crashes.

Friction between the gas and dust during a collision can have a major effect on the galaxies involved, morphing the shape of the original galaxies and creating interesting new structures. The collision usually triggers major bursts of star formation. This also occurred in IRAS 23436+5257; the bright blue patches in this galaxy are cluster of hot, young stars.

When you look up at the calm and quiet night sky it is not always easy to picture it as a dynamic and vibrant environment with entire galaxies in motion, and crashing into whatever crosses their path. The motions are, of course, extremely slow, and occur over millions or even billions of years.

The aftermath of these galactic collisions helps scientists to understand how these movements occur and what may be in store for our own Milky Way, which is on a collision course with the Andromeda Galaxy (Messier 31), a neighboring galaxy. They will probably collide in about 4 billion years, merge and finally turn into a giant elliptical galaxy.

This image is taken with the Advanced Camera for Surveys on the Hubble Space Telescope, using two different color filters. This version of the image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt (http://www.flickr.com/photos/geckzilla/7069025611/). Hidden Treasures is an initiative to invite astronomy enthusiasts to search the Hubble archive for stunning images that have never been seen by the general public.

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