What Is This Large Quasar Cluster?

The huge quasar group was found in 20 13 by one of the same researchers that previously discovered other large quasar groups. It's 73 quasars all in a big cluster, like four billion light years from end to end. And they're clustered together in a sort of interesting, sort of blobby shape. The question about being a gravitationally bowed object is, really, is gravity to dominant force? Is it the thing that's holding it together?