When radio waves appeared to astronomers to be drawing a pink musical key in the middle of space, they were not only faced with a curious sight, but also a mystery that had remained hidden behind the dust of our galaxy.
New observations have revealed that these glowing filaments, located about 1.55 billion light-years away, may be the remnants of an ancient explosion of a supermassive black hole, revived by the collision of two galaxy clusters after their radiation had dimmed.
An old explosion regains its sound
Radio images revealed a network of interconnected filaments and loops, the largest of which extends to about 2,400 light-years. Their shapes are reminiscent of the musical note "G clef," but the similarity is purely visual, not an audible acoustic phenomenon in space.
X-rays revealed a vast cloud of hot gas containing a massive cluster of galaxies. Temperature measurements and light distribution indicate that the cluster is experiencing disturbances caused by the merger of two galaxies. The team estimated its mass at approximately 600 trillion solar masses, placing it among the largest structures held together by gravity.
The researchers suggest that a supermassive black hole long ago ejected charged particles and magnetic fields into surrounding space. As the particles lost energy, the radio waves dimmed, before the gas movement caused by the collision of the two clusters compressed or energized them again.
How did the X-rays reveal the collision?
The team not only observed a hot cloud, but also compared its radiation distribution to a regular elliptical model. After removing the regular part, two brighter regions appeared to the right and left of the center, supporting the theory that a collision occurred along this axis hundreds of millions of years ago.
Astronomers call such remnants that regain their luminosity "radio phoenixes," referring to the reappearance of a faint source. Measurements show that the filament's radiation weakens significantly at higher frequencies, evidence consistent with the presence of ancient particles that have lost a large portion of their energy.
Tags:
science