Hercules Saves the Day

Want to explore galaxies?  Look no further than the latest image of interacting galaxies in the Hercules Cluster.  It’s chock full of ’em!

This glorious image was taken with the VLT Survey Telescope (VST) at ESO’s Paranal Observatory.  When you dig into this image, you can see a collection of interacting galaxies that lie about 500 million light-years away.

This cluster is a rather interesting one and the story accompanying this image on the ESO Web site is a study in galaxy interactions.  As well as being somewhat irregular in shape, there are many different types of galaxies.  Some are young and active, creating many new stars.  About the only type of galaxies this cluster doesn’t have are giant ellipticals.

You’ll find galaxy pairs getting up close and personal with each other, well on their way to merging into single, larger galaxies. The numerous other interactions, and the large number of gas-rich, star-forming spiral galaxies in the cluster, make the members of the Hercules cluster look like the young galaxies that astronomers see in the distant universe (farther back in cosmic history).  Because of this similarity, astronomers believe that the Hercules galaxy cluster is a relatively young cluster.  It’s thought to be a collection of at least three smaller subclusters and groups that are all assembling themselves into a much larger structure within the cluster.  But, the interactions don’t stop there… the Hercules cluster itself is merging with other large clusters to form a galaxy supercluster.  All this information is giving astronomers good insight into how larger galaxy structures and clusters assemble themselves together in the universe over cosmic time.  Stay tuned!