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Astronomers are rather excited by the discovery of a colossal galactic fountain with a supermassive black hole ‘mechanical pump’ at its centre.
Potentially revealing a wealth of information on the life cycles of galaxies, astronomers using the European Southern Observatory’s (ESO) Very Large Telescope (VLT) have discovered a gigantic fountain of molecular gas, powered by a supermassive black hole.
Located approximately 1bn light years away in the brightest galaxy of the Abell 2597 cluster, the black hole found in the galaxy’s centre has been observed pumping a vast spout of cold molecular gas into space. Once it has been spewed out, the gas then ‘rains’ back on to the black hole as an intergalactic deluge.
According to the research team that made the discovery, led by Dr Grant Tremblay of the Harvard-Smithsonian Center for Astrophysics, the full cycle of the inflow and outflow of such a vast cosmic fountain has never been observed in combination before.
“This is possibly the first system in which we find clear evidence for both cold molecular gas inflow toward the black hole and outflow or uplift from the jets that the black hole launches,” Tremblay said. “The supermassive black hole at the centre of this giant galaxy acts like a mechanical pump in a fountain.”
Composite image of the Abell 2597 galaxy cluster showing the fountain-like flow of gas powered by the supermassive black hole. The yellow ALMA data shows infalling material and the red MUSE data shows material launched in a vast spout by the black hole. Image: ALMA (ESO/NAOJ/NRAO), Tremblay et al; NRAO/AUI/NSF, B Saxton; NASA/Chandra; ESO/VLT
Observing the life cycles of galaxies
The discovery was made using VLT’s ALMA and MUSE instruments, the first of which tracked the position and motion of the carbon monoxide molecules within the nebula that can reach temperatures as low as -260 degrees Celsius. Data from the second instrument was used to track warmer gas launched out of the black hole in the form of jets.
With these two sets of data, the astronomers could get a complete picture of the enormous display, with the cold gas falling towards and igniting the black hole. This in turn led to the launching of fast-moving jets of incandescent plasma into the vast void.
The resulting galactic fountain means that the ejected plasma has no hope of escaping the galaxy’s gravitational pull, forcing it to cool down and fall towards the black hole, completing the cycle.
The research team believes this could explain a lot about the life cycles of galaxies, believing the discovery to not only be common, but essential to galaxy formation.
The team’s research has now been published in The Astrophysical Journal.
