A new look at the galaxy-shaping power of black holes

A new look at the galaxy-shaping power of black holes
It wasn't until the advent of X-ray astronomy that the full picture of the at the galaxy-shaping power of black holes began to emerge with the ability to see plasma. In visible light, the Perseus cluster appears to contain many individual galaxies, separated by seemingly-empty space. In an X-ray image, however, the individual galaxies are invisible, and the plasma atmosphere, centred on the cluster's largest galaxy, known as NGC 1275, dominates the scene. In this image, active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission. NGC 1275 accretes matter as entire galaxies fall into it, ultimately feeding a supermassive black hole at the galaxy's core. This color composite image, recreated from archival Hubble Space Telescope data, highlights the resulting galactic debris and filaments of glowing gas, some up to 20,000 light-years long. Credit: Data - Hubble Legacy Archive, ESA, NASA; Processing - Al Kelly

Data from a now-defunct X-ray satellite is providing new insights into the complex tug-of-war between galaxies, the hot plasma that surrounds them, and the giant black holes that lurk in their centres.

Launched from Japan on February 17, 2016, the Japanese space agency (JAXA) Hitomi X-ray Observatory functioned for just over a month before contact was lost and the craft disintegrated. But the data obtained during those few weeks was enough to paint a startling new picture of the dynamic forces at work within galaxies.

New research, published in the journal Nature today, reveals data that shows just how important the giant black holes in galactic centres are to the evolution of the galaxies as a whole.

"We think that supermassive black holes act like thermostats," said Brian McNamara, University Research Chair in Astrophysics at the University of Waterloo. "They regulate the growth of galaxies."

Champagne bubbles of plasma

During its brief life, the Hitomi satellite collected X-ray data from the core of the Perseus cluster, an enormous gravitationally-bound grouping of hundreds of galaxies. Located some 240 million light years from earth, the Perseus cluster is one of the largest known structures in the universe. The cluster includes not only the ordinary matter that makes up the galaxies, but an "atmosphere" of hot plasma with a temperature of tens of millions of degrees, as well as a halo of invisible dark matter.

Earlier studies, going back to the 1960s, have shown that each of the galaxies in the cluster - and indeed most galaxies - likely contains a in its centre, an object 100 million to more than ten billion times as massive as our sun.

A new look at the galaxy-shaping power of black holes
Hitomi employed an X-ray spectrometer which measures the Doppler shifts in emissions from the plasma; those shifts can then be used to calculate the speed at which different parts of the plasma are moving. At the heart of the spectrometer is a microcalorimeter; cooled to just one-twentieth of a degree above absolute zero, the device records the precise energy of each incoming X-ray photon. Getting an X-ray satellite equipped with a microcalorimeter into space has proved daunting: McNamara was deeply involved with NASA's Chandra X-ray Observatory, launched in 1999, that was initially set to include a microcalorimeter, but the project was scaled back due to budget constraints, and the calorimeter was dropped. Another mission with the Japanese space agency known as ASTRO-E was equipped with a microcalorimeter; it was set for launch in 2000, but the rocket exploded shortly after liftoff. A third effort, Japan's Suzaku satellite, launched in 2005, but a leak in the cooling system destroyed the calorimeter. Hitomi launched and deployed perfectly, but a series of problems with the attitude control system caused the satellite to spin out of control and break up. Credit: University of Waterloo

"These giant black holes are among the universe's most efficient energy generators, a hundred times more efficient than a nuclear reactor," said McNamara from Waterloo's Department of Physics and Astronomy in the Faculty of Science. "Matter falling into the black hole is ripped apart, releasing vast amounts of energy in the form of high speed particles and thermal energy."

This heat is released from just outside the black hole's event horizon, the boundary of no return. The remaining matter gets absorbed into the black hole, adding to its mass. The released energy heats up the surrounding gas, creating bubbles of hot plasma that ripple through the cluster, just as bubbles of air rise up in a glass of champagne.

The research is shedding light on the crucial role that this hot plasma plays in galactic evolution. Researchers are now tackling the foremost issue in the formation of structure in the universe and asking: why doesn't most of the gas cool down, and form stars and galaxies? The answer seems to be that bubbles created by blasts of energy from the black holes keep temperatures too high for such structures to form.

"Any time a little bit of gas falls into the black hole, it releases an enormous amount of energy," said McNamara. "It creates these bubbles, and the bubbles keep the plasma hot. That's what prevents galaxies from becoming even bigger than they are now."

Because plasma is invisible to the eye, and to optical telescopes, it wasn't until the advent of X-ray astronomy that the full picture began to emerge. In visible light, the Perseus cluster appears to contain many individual galaxies, separated by seemingly-empty space. In an X-ray image, however, the individual galaxies are invisible, and the plasma atmosphere, centred on the cluster's largest galaxy, known as NGC 1275, dominates the scene.

Although the black hole at the heart of NGC 1275 has only one-thousandth of the mass of its host galaxy, and has a much smaller volume, it seems to have a huge influence on how the galaxy and how the surrounding hot plasma atmosphere evolve.

"It's as though the galaxy somehow knows about this black hole sitting at the centre," said McNamara. "It's like nature's thermostat, that keeps these galaxies from growing. If the galaxy tries to grow too fast, matter falls into the black hole, releasing an enormous amount of energy, which drives out the matter and prevents it from forming new stars."

A new look at the galaxy-shaping power of black holes
An X-ray image reveals the hot plasma that envelopes the Perseus cluster. Located some 240 million light years from earth, the Perseus cluster is one of the largest known structures in the universe. The cluster includes not only the ordinary matter that makes up the galaxies, but an "atmosphere" of hot plasma with a temperature of tens of millions of degrees, as well as a halo of invisible dark matter. Data from the Hitomi satellite reveals that although the black hole at the heart of the Perseus cluster has only one-thousandth of the mass of its host galaxy, and has a much smaller volume, it seems to have a huge influence on how the galaxy and how the surrounding hot plasma atmosphere evolve. Credit: University of Waterloo

McNamara notes that the actual event horizon of the black hole is about the same size as our solar system, making it as small compared to its host galaxy as a grape is to the Earth. "What's going on in this tiny region is affecting a vast volume of space," he said.

Thanks to the black hole's regulatory effect, the gas that would have formed new stars instead remains a hot plasma - whose properties Hitomi was designed to measure.

Doomed satellite missions

Hitomi employed an X-ray spectrometer which measures the Doppler shifts in emissions from the plasma; those shifts can then be used to calculate the speed at which different parts of the plasma are moving. At the heart of the spectrometer is a microcalorimeter; cooled to just one-twentieth of a degree above absolute zero, the device records the precise energy of each incoming X-ray photon.

Getting an X-ray satellite equipped with a microcalorimeter into space has proved daunting: McNamara was deeply involved with NASA's Chandra X-ray Observatory, launched in 1999, that was initially set to include a microcalorimeter, but the project was scaled back due to budget constraints, and the calorimeter was dropped. Another mission with the Japanese space agency known as ASTRO-E was equipped with a microcalorimeter; it was set for launch in 2000, but the rocket exploded shortly after liftoff. A third effort, Japan's Suzaku satellite, launched in 2005, but a leak in the cooling system destroyed the calorimeter. Hitomi launched and deployed perfectly, but a series of problems with the attitude control system caused the satellite to spin out of control and break up.

The data from Hitomi, limited as it is, is enough to make astronomers re-think the role of plasma in galactic evolution, according to McNamara. "The plasma can be thought of forming an enormous atmosphere that envelopes whole clusters of galaxies. These hot atmospheres represent the failure of the past—the failure of the universe to create bigger galaxies," he said. "But it's also the hope for the future. This is the raw material for the future growth of - which is everything: stars, planets, people. It's the raw material that in the next several billion years is going to make the next generation of suns and solar systems. And how rapidly that happens is governed by the black hole."

The observations give researchers, for the first time, a direct measurement of the turbulent speed of the . "This measurement tells us how the enormous energy released by supermassive regulates the growth of the galaxy and the black hole itself," said McNamara.


Explore further

ALMA finds a swirling, cool jet that reveals a growing, supermassive black hole

More information: The quiescent intracluster medium in the core of the Perseus cluster, Nature, DOI: 10.1038/nature18627
Journal information: Nature

Citation: A new look at the galaxy-shaping power of black holes (2016, July 6) retrieved 13 October 2019 from https://phys.org/news/2016-07-galaxy-shaping-power-black-holes.html
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Jul 06, 2016
"It's as though the galaxy somehow knows about this black hole sitting at the centre," said McNamara. "It's like nature's thermostat, that keeps these galaxies from growing. If the galaxy tries to grow too fast, matter falls into the black hole, releasing an enormous amount of energy, which drives out the matter and prevents it from forming new stars."

Confused merger maniac loosing his marbles. The supermassive grey hole core star produces the matter ejected therefrom. Otherwise, tell us how accretion of surrounding gas could possibly sustain such a long column of ejected material along the jets. Go ahead maniac, make my day.

Jul 06, 2016
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Jul 06, 2016
Why not - the BH shaping power of Galaxies?

Jul 07, 2016
hmmm interesting... what about our punny one tho? 4mil masses seems so small and our galaxy is supposed to be a pretty decent size too. so many questions we might never answer :(

Jul 07, 2016
Why not - the BH shaping power of Galaxies?

It's always been my understanding that it's what's in the middle that counts.
In this case, its galactic mass with a BH on one side and a dark matter envelope on the other...
Don't ask for specifics cuz I don't have any...:-)
it's just a feeling...

Jul 07, 2016
That top pic is amongst my favorites ever. The arms of the plasma filaments are leaving behind veils of newly formed stars, you can tell they are newly formed by their bright blue colors, and there are several arms so doing. The end shape will be like the background galaxy (that I have pointed out several times) at the 2 O' Clock Position in the background, how it shows the full magnetic shell. The larger one in front is doing the same thing, on a Quantumly larger form. (see recent article on quantum functions being universal) so the one in front is going to be a Larger Atom, scalewise. What it's atomic number, I am not sure, but the physical theorists with hard numbers should be ale to work that out. If one considers electrons and their attraction (but little 'mass') as Dark Matter, then it may well work out so much easier, given that notion.

Jul 07, 2016
I see that Perseus Supercluster as a form of Fusion, and here two atoms of that mass are clearly fusing to become a new, stable form, once it calms down a might an a few hundred million or a billion years or so.

Jul 07, 2016
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Jul 07, 2016
The supermassive grey hole core star produces the matter ejected therefrom.


BHs do not violate the First Law and create mass. Ejected mass and energy is the result of the spaghettification process where entering matter is shredded into its constituent parts of mass and spacetime. If matter tries to enter the event horizon too rapidly, a portion is observed to be ejected into intergalactic space as an energetic flux.


Jul 07, 2016
The supermassive grey hole core star produces the matter ejected therefrom.


BHs do not violate the First Law and create mass. Ejected mass and energy is the result of the spaghettification process where entering matter is shredded into its constituent parts of mass and spacetime. If matter tries to enter the event horizon too rapidly, a portion is observed to be ejected into intergalactic space as an energetic flux.

Yours is simply an assumption based on finite understanding common to the widespread mental illness of merger mania. Limited technical understanding leads right back into the mania, like a run-away feedback loop, leaving you firmly stuck in your convincing conclusion. (There is the clue.) But thanks for trying.

Jul 07, 2016
Yours is simply an assumption based on finite understanding common to the widespread mental illness of merger mania.


Came here for textbook examples of narcissistic personality disorder- was not disappointed.

Jul 07, 2016
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Jul 07, 2016
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Jul 07, 2016
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