The National Aeronautics and Space Administration (NASA) has recently been racking up one space victory after another...like a master pool player having the run of the table. As if on cue, NASA has done it again, making a another stellar discovery with the orbiting Chandra Observatory, the deep-space X-ray telescope.
This momentous NASA discovery moves the entire field of astronomy another notch forward and follows on the heels of the Jet Propulsion Laboratory's historic achievement of safely navigating the advanced robotic explorer Curiosity to the arid Martian plains and a soft touchdown into the sprawling maw of the massive meteor crater, Gale.
The Chandra images of a supergalactic cluster of galaxies 5 billion light years from Earth, sheds new light on a mystery that's beguiled astronomers for centuries: what is the process that galaxies use to create new stars?
The Phoenix Cluster
Dubbed the Phoenix Cluster by the scientists that studied its properties, the incredible stellar mass, officially listed as Cluster SPT-CLJ2344-4243, spews out more than 700 new stars a year and is one of the most intense X-ray producing clusters in the known universe. Compare the annual number of newborn stars in the Phoenix Cluster to more normal-sized galaxies like the Milky Way. At best, our galaxy produces several new stars each year.
Michael McDonald—Hubble fellow at MIT and lead author of the paper published in the journal Nature ["A massive, cooling-flow-induced starburst in the core of a luminous cluster of galaxies"]—said at a NASA press conference held August 15th that, “This extreme rate of star formation was unexpected."
McDonald and other scientists are extremely excited about the discovery. Why? McDonald explained, “Central galaxies have typically been referred to as ‘red and dead’—just a bunch of old stars orbiting a massive black hole, and there’s nothing new happening. But the central galaxy in this cluster has somehow come to life, and is giving birth to prodigious numbers of new stars.”
Not only does the study of the Phoenix Cluster promise new insights on exactly how the process of new stars are born, but how frequently the process takes place and over what length of time. Does a galaxy's star-making ability last only several millions of years or extend past 100 million years? No one is sure.
Mother of all clusters
The Phoenix Cluster is not the only giant cluster in the universe, but may be the "mother of all clusters." The galactic group extends across roughly 7.3 million light years of space.
The LA Times notes: "At first, astronomers didn't realize how unique the cluster was. But in the months that followed, McDonald and his co-authors analyzed a variety of signals from the cluster including X-rays, optical light, and infrared radiation it emitted-and realized they had a 'remarkable' object on their hands."
The cluster is so remarkable some scientists suggest a massive black hole may be behind the assemblyline prodyction of stars. If that is true, it would certainly make it a unique galactic cluster beyond its massive size.
Other astronomers argue the rate of star birth is not being caused by permutations of gravity effects from one or more black holes, even a supermassive black hole. In fact, the star births may be happening at such a prodigious rate for exactly the opposite reason.
Cooling, not heating, creates stars
University of Cambridge astrophysicist Martin Rees participated in the news conference and explained that most galaxies with black holes are thought to limit the formation of new stars. The heat generated by the massive black holes energizes galactic gas clouds and keeps them from condensing into proto-stars.
"It's clear that this [Phoenix] is a cluster where the feedback from the black hole is inefficient," Rees explained during the conference. “It's by studying these extreme phenomena that we understand the symbiosis between galaxies and black holes.”
The accelerated "cooling of the hot gases in the centers of galaxies is what drives the formation of stars," writes the LA Times. "The Phoenix cluster's high X-ray output was an indication that the gases in its center were cooling very, very rapidly, the scientists said—at such a high rate that the cluster could potentially create thousands of stars a year."
More about NASA's discovery and a video presentation are here.