Posted on Saturday, October 12, 2013
Galaxy PGC 6240 depicted in the video below is located in the constellation Hydrus. It is an elliptical galaxy which has odd shells around it.
But that's not the most interesting part, as one can find images of galaxies of all sorts of shapes in the Hubble galleries.
The interesting part is that the globular clusters that form a halo around the galaxy, that are normally of the same age, are not all equally old. It is thought that both the shells around the galaxy and the differences in the ages of the globular clusters have been caused by a galactic merger in it's (astronomically) recent past.
During the merger the star systems of the two galaxies don't collide, but they interact with each other gravitationally leading stars to go into different orbits around the center of the galaxy and forming these kinds of structures as can be seen in the video. Because of the merger new globular cluster start to form as well, hence the difference in ages (The first ones started forming a long long time ago in a galaxy far away).
So in a way finding globular clusters of different ages around a galaxy let's the scientist know that something happened at around that time when the clusters started to form.
Credit: NASA & ESA. Music: movetwo. Acknowledgement: Judy Schmidt
But that's not the most interesting part, as one can find images of galaxies of all sorts of shapes in the Hubble galleries.
The interesting part is that the globular clusters that form a halo around the galaxy, that are normally of the same age, are not all equally old. It is thought that both the shells around the galaxy and the differences in the ages of the globular clusters have been caused by a galactic merger in it's (astronomically) recent past.
During the merger the star systems of the two galaxies don't collide, but they interact with each other gravitationally leading stars to go into different orbits around the center of the galaxy and forming these kinds of structures as can be seen in the video. Because of the merger new globular cluster start to form as well, hence the difference in ages (The first ones started forming a long long time ago in a galaxy far away).
So in a way finding globular clusters of different ages around a galaxy let's the scientist know that something happened at around that time when the clusters started to form.
Credit: NASA & ESA. Music: movetwo. Acknowledgement: Judy Schmidt
Labels: Galactic merger, PGC 6240