All in the same image

Mar 17, 2009 07:41 GMT  ·  By

The Very Large Telescope has just photographed one of the most impressive galactic collisions in astronomy history, while at the same time capturing the explosion of a supernova, all in the same image. The two colliding galaxies, known collectively as Arp 261, are located in the Libra constellation and are more than 70 million light-years away from us. Their destructive merger gives birth to some unusual and very interesting cosmic events, which scientists at the VLT are currently studying.

The recent picture is the most detailed one of the two star systems, but researchers at the European Southern Observatory (ESO) admit that the main goal of their study has not been to detect the motions of these two formations, but to observe the supernova that exploded right outside the giant “boxing ring.”

And the slow-motion merger is a sight to behold. It may appear that the two galaxies are colliding very slowly, but they are actually exchanging mass at a very high speed. Gases and cosmic dust clouds are hitting each other at an increased velocity and they give birth to numerous new clusters of super-hot and massive stars, whose faith is unclear. In addition to forming new celestial bodies, the collision also drastically alters the path of existing ones, making them swirl and take on new trajectories.

This creates the faint halo that can be seen on the edge of Arp 261 and that makes the new, resulting galaxy look very chaotic and exhibit a shape that has never before been seen in such a formation. What's even more interesting is that, taken separately, neither of the star aggregates has been larger than the Magellanic Cloud orbiting our own Milky Way, which makes them dwarf galaxies. This means that mergers could be one of the main ways in which larger such systems are formed in the vastness of space.

The main target of the investigation has been an object designated SN 1995N, which is an exploded supernova. The reason astronomers have looked at it again has been because it still shows a very distinct glow, even though it blew up more than 7 years ago.

Also, the body emits X-rays, a highly-unusual thing for a supernova. Astrophysicists hypothesize that this may happen because the star was located in a very dense region of space and the powerful blast of the explosion passed through some types of matter, generating the radiation.