Merging Galactic Companions Imaged by ESO Telescope

In a recent series of scientific observations of the night sky, astronomers managed to capture an amazing image of a pair of galaxies. The members in this group are locked together in a dance that will most likely lead to a merger in the distant future.

The two formations are currently located fairly close to each other, experts say. This information can be extracted from in-depth analysis of how visible matter is distributed in the two objects.

Already, each of them is beginning to feel the other's gravitational influence. Eventually, this interplay will lead to massive distortions developing in each of the galaxies. As this happens, the merger will begin, and will continue for millions of years.

In the new image, the right hand-side galaxy is called NGC 3166, while its companion at the left has been dubbed NGC 3169. The latter's spiral shape is already being significantly influenced by the powerful, gravitational tug-of-war that is taking place.

On the other hand, the dust lanes that are clearly visible in NGC 3166 are starting to become fragmented. Since the two objects were caught in the early stages of mergers, experts can study them to fill in some blanks they have in theories explaining how this complex process takes place.

Usually, they would use computer models for this, but it would take a supercomputer years to produce a detailed simulation of what happens when two galaxies collider. Processes such as black hole mergers, the formation of new stellar nurseries, and the explosion of supernovae are very complex.

But the new study provides some of the data experts have been looking for. Astronomers used the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile to conduct the work.

They imaged both galaxies using the Wide Field Imager (WFI) instrument, which is very well suited to conduct such investigations. The galactic system was located some 70 million light-years away, in the direction of the constellation Sextans.

Calculations show that the two objects are separated by a distance of only 50 000 light-years. Though this may seem like a lot at first, it's only half the diameter of the Milky Way. Considering the scale of the two galaxies, the distance suddenly becomes rather short.

“Spiral galaxies like NGC 3169 and NGC 3166 tend to have orderly swirls of stars and dust pinwheeling about their glowing centers,” experts at the European Southern Observatory say in a statement accompanying the image.

“Close encounters with other massive objects can jumble this classic configuration, often serving as a disfiguring prelude to the merging of galaxies into one larger galaxy,” they conclude.