The Galactic Collision That Wasn'tCategory: Science & Technology
Posted: June 22, 2012 01:56PM
The Universe has many interesting and beautiful structures to see and possibly one of the most amazing is a galactic collision. When two, and occasionally more, galaxies start to fall into each other, their mutual gravity pulls each other apart, hurling dust lanes and stars to the surrounding cosmos. The resulting structure(s) can be truly amazing. Now researchers have found with the Hubble Space Telescope what some may at first think is a galactic collision, but is actually something rarer, and potentially more informative; a galactic alignment.
NGC 3314A and NGC 3314B are two spiral galaxies that are separated by tens of millions of light years but have lined up perfectly, so 3314A is on top of 3314B. This causes a few interesting distortions to the image, including backlighting of 3314A's dust lanes and gravitational microlensing of 3314B. Gravitational lensing is the bending of light caused by gravity and is normally seen when an entire galaxy cluster is in front of a more distant galaxy. In this case, with only one galaxy in front, the lensing is going to be much weaker, but should still be present. The observations of the NGC 3314 structure, which includes both galaxies, were actually made to study the microlensing phenomenon.