Posted on Nov 7, 2018 The huge elliptical galaxy Abell 2597, which lies at the heart of one of the…
Posted on Nov 7, 2018
The huge elliptical galaxy Abell 2597, which lies at the heart of one of the universe’s most massive galaxy clusters, has revealed a cosmic secret to the evolution and lifespan of massive galaxies. 1
9659003] “Galaxy evolution can be pretty chaotic, and big galaxies like this tend to live hard and the young,” says Dr. Timothy Davis, Ernest Rutherford Fellow and Lecturer here at Cardiff University in the department of Physics and Astronomy. Who focuses on the evolution of galaxies, and how they assemble from the cosmic soup at high redshift to become the beautiful and diverse populations we see around us in the local universe.
For the first time, says Davis, we have been able To observe the full cycle of a supermassive black hole fountain, that acts to regulate this process, prolonging the life of galaxies by drawing in solid stores or cold molecular gas and then spraying them back out again in an ongoing cycle.
Using the Atacama Large Millimeter / Submeter Array (ALMA) or Telescopes in Chile, the team, which includes researchers from Cardiff University, has observed a supermassive black hole acting like a ‘monumental fountain’ in the middle of a galaxy, named Abell 2597, on a billion light-years from Earth.
In the ESO image of Abell 2597, above, the background (blue) is from the NASA / ESA Hubble Space Telescope. The foreground (red) is ALMA data showing the distribution of carbon monoxide gas in and around the galaxy. The pull-out box shows the ALMA data of the “shadow” (black) produced by absorption of the millimeter-wave length light emitted by electrons whizzing around powerful magnetic fields generated by the galaxy’s supermassive black hole. The shadow indicates that cold clouds of molecular gas are raining on the black hole.
Galaxy evolution can be chaotic and messy, but it seems that streams of cold gas spraying out of the region around supermassive black holes may act to calm the storm.
According to the Cardiff researchers, this whole system operates via a self-regulatory feedback loop. This is a global team of scientists who have provided the first clear and compelling evidence of this process in action. De inkomende materiaal geeft energie voor de fontein als het “dreineert” naar het centrale zwarte gat, zoals water binnen de pomp of een fontein. This gas then causes the black hole to ignite with activity, launching high-speed jets or super-heated material that shoot out of the galaxy.
As it travels, this material pushes out clumps and streamers of gas into the galaxy’s expansive halo, where it eventually rains back into the black hole, triggering the entire process anew.  By studying the location and motion of molecules of carbon monoxide (CO) with ALMA, which shine brightly in millimeter-wave length light, the researchers were able to measure the motion of the gas as it falls into the black hole.
Det er fra disse plumes of gas at nye stjerner er dannet i galakser, og forskerne tror at den prosess de har observert, kunne være felles over hele universet og, mer viktig, kunne være avgjørende for utviklingen av massive galakser som denne.  “The supermassive black hole at the center of this giant galaxy acts like a mechanical pump in a water fountain,” said Grant Tremblay, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusett s, and lead author on the paper. “Dette er et av de første systemene hvor vi finner klare bevis for både kold molekylær gassinstrømning mot det svarte hullet og utstrømning eller oppløftning fra de stråler som det sorte hullet lanserer.”
The Daily Galaxy via Cardiff University og The Conversation
Image credits: NRAO / AUI / NSF; D. Berry and image top of page: B. Saxton (NRAO / AUI / NSF) / G. Tremblay et al ./NASA/ESA Hubble / ALMA (ESO / NAOJ / NRAO)