It is a well known fact that galaxies are formed in clusters, and they create interlinked chains and structures creating a spider web across the cosmos. NASA’s Hubble space telescope has discovered two colliding elliptical galaxies wrapped by a string of pearls which is a structure of around 100,000 light years in length.
The structure is like a string of blue colored pearls, and are evenly spaced along the chain at separations of 3,000 light-years from one another. The pair of elliptical galaxies is embedded deep inside the dense galaxy cluster SDSS J1531+3414.
Astronomers are totally clueless of the origin and ultimate fate of the object, but the answer about which they are least bothered will be definitely extraordinary, said the scientists.
“We were surprised to find this stunning morphology, which must be very short-lived” (perhaps about 10 million years, which is a fraction of the time it takes for galaxies to merge), said Grant Tremblay of the European Southern Observatory in Garching, Germany. “We’ve long known that the ‘beads on a string’ phenomenon is seen in the arms of spiral galaxies and in tidal bridges between interacting galaxies. However, this particular supercluster arrangement has never been seen before in giant merging elliptical galaxies,” he said. “We have two monsters playing tug-of-war with a necklace, and its ultimate fate is an interesting question in the context of the formation of stellar superclusters and the merger-driven growth of a galaxy’s stellar component.”
The first hypothesis of the astronomers was that the “string of pearls” was in reality a lensed image from one of these background galaxies, but their recent follow-up observations with the Nordic Optical Telescope definitively rules this possibility out.
The formation of the clusters is attributable to the collision of the galaxies.
“This is a beautiful demonstration of the profound scale-invariance of the fundamental laws of nature,” Tremblay added. The underlying physical processes that give rise to the “beads on a string” morphology are related to the Jeans instability, describing the behavior of self-gravitating clumps of gas. It’s analogous to the process that causes a falling column of water to disrupt, explaining why rain falls in drops rather than in continuous filaments from clouds. Water coming out of the kitchen tap eventually breaks into a series of droplets, and a very similar process is happening in SDSS J1531+3414. “We see the same physics on 100,000-light-year scales that we see in our kitchen sinks and inkjet printers,” said Tremblay.
The galaxy cluster is part of a Hubble program that includes observing 23 massive clusters that create powerful gravitational lensing effects on the sky. The clusters were first cataloged in the Sloan Digital Sky Survey (SDSS). The project was devised to develop the most detailed three-dimensional maps ever made of the universe.