Astronomers have discovered a spectacular gaseous fountain within a far-away galaxy cluster known as Abell 2597. Located about 1.1 billion light-years from Earth in the Aquarius constellation (“The Water-Bearer”), Abell 2597 is home to about 50 galaxies, centered around a massive elliptical galaxy descriptively named the Abell 2597 Brightest Cluster Galaxy.
Scientists studying the enormous galaxy cluster with three telescopes — the Atacama Large Millimeter/submillimeter Array (ALMA), the Multi-Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s (ESO) Very Large Telescope (VLT), and NASA’s Chandra X-ray Observatory — have picked up an interesting phenomenon occurring in cluster’s brightest galaxy, the core of the Abell 2597.
Molecular Gas Fountain
The galaxy hosts a supermassive black hole at its center, which constantly churns the molecular gas around it, fueling a fountain-like flow that gets sprayed through space over vast distances of up to 100,000 light-years. Described as a “cosmic fountain,” this enthralling phenomenon relies on gravity and electromagnetic forces to create a beautiful and long-lasting flow of gas that brings to mind the antique water fountains of a bygone, pre-electricity age.
“The supermassive black hole at the center of this giant galaxy acts like a mechanical pump in a fountain,” said Grant Tremblay of at the Harvard-Smithsonian Center for Astrophysics, who published a study on this incredible process, featured in the Astrophysical Journal.
A composite image of the gas fountain in Abell 2597 was released by NASA on December 13, along with a summary of how this phenomenon is created. Originally unveiled by ESO last month, the photograph reveals the three main features that power this cosmic fountain — cold gas, hot gas, and giant cavities carved out by fast-moving jets of gas.
“A massive black hole at the heart of a distant galaxy has been observed pumping a vast spout of cold molecular gas into space, which then rains back onto the black hole as an intergalactic deluge. The in and outflow of such a vast cosmic fountain has never before been observed in combination,” ESO explained at the time.
According to NASA, the process starts with cold gas falling toward the black hole, given a yellow color by ALMA. When this material reaches the vicinity of the black hole — a behemoth weighing 3 billion times the mass of the sun — its gravity causes the cold gas to swirl around at high speeds. This heats up the gas to millions of degrees, eventually generating fast-moving jets of gas that shoot out of the galaxy.
The gas jets disperse vast amounts of hot, ionized gas floating in the medium that surrounds the black hole, imaged in purple by Chandra. Their force carves enormous cavities that stretch away from the galaxy’s center. Imaged in red by MUSE/VLT, these cavities then fill up with warm and cold gas, which is transported away from the black hole only to be pulled back in.
This ongoing cycle spans the innermost 100,000 light-years of the galaxy and is estimated to last for tens of millions of years.
The dense clouds of cold intergalactic gas that rain down on the black hole were first observed by ALMA in 2016, the ESO previously reported.
“Although it has been a major theoretical prediction in recent years, this is one of the first unambiguous pieces of observational evidence for a chaotic, cold rain [of gas] feeding a supermassive black hole,” Tremblay stated at the time, when the scientist published another study on the stunning events occurring within Abell 2597’s brightest galaxy.