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Galaxy Punches Through Neighbor to Spawn Giant Ring of Black Holes
A giant ring of black holes has been discovered 300 million light-years away, offering new clues about what happens when galaxies collide. [...] The observed ring of black holes or neutron stars is believed to be the result of a galaxy collision. The galaxies were likely drawn together by gravity, and the gravitational force from one galaxy created waves in the gas surrounding its neighbor, which, in this case, is AM 0644. The ripples would have then caused the gas to expand or clump together in denser areas, triggering the birth of new stars.
"The most massive of these fledgling stars will lead short lives — in cosmic terms — of millions of years," representatives from the Chandra X-ray Observatory said in a statement. "After that, their nuclear fuel is spent, and the stars explode as supernovas, leaving behind either black holes with masses typically between about five to twenty times that of the sun, or neutron stars with a mass approximately equal to that of the sun." The black holes or neutron stars have close cosmic companions from which they siphon gas. This gas falls inward and is heated by friction, creating the bright X-rays detected by Chandra, according to the statement.
Also at Bad Astronomy.
(Score: 2) by c0lo on Wednesday September 12 2018, @09:26AM (11 children)
Friction... with exactly what? What's there to rub against? Not like the black hole will have an atmosphere, is it?
Are we talking about high speed collision between gas atoms?
Are we talking about EM emmision of charged particles moving with acceleration (e.g. cyclotron radiation?)
I can't imagine particles grinding at high speed against the black hole's horizon and sparking in the process.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday September 12 2018, @10:03AM
Internal friction of the gas.
(Score: 3, Informative) by RS3 on Wednesday September 12 2018, @12:54PM (3 children)
The gas atoms and molecules are increasingly compressed and collide as they fall into the black hole's gravitation. The forces and energies involved are indeed quite unimaginable.
(Score: 2) by c0lo on Wednesday September 12 2018, @01:40PM (2 children)
Like how much compressed?
My imagination loves a challenge.
(my point: thanks, but I'd really like some hard-science type of info)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Informative) by RS3 on Wednesday September 12 2018, @02:49PM
https://www.google.com/search?q=pressure++event+horizon [google.com]
And if you're feeling much too happy, read this: https://arxiv.org/pdf/1202.4995.pdf [arxiv.org], plug in some numbers, use MatLab / MathCad / Maple / whatever your favorite math software or grind it out like the ancients did. We'll wait for the results... :-}
Since there's potentially much we still don't know about the interior of a star, let alone a black hole, here's some generally accepted stuff: http://burro.case.edu/Academics/Astr221/StarPhys/estcent.html [case.edu]
At the sun'c core, the pressure is estimated at 3.4 x 10^11 ATM.
Here are some more interesting facts, but they don't give all the good numbers: http://www.smartconversion.com/otherInfo/Surface_pressure_of_planets_and_the_sun.aspx [smartconversion.com] and don't take the sun's surface pressure too seriously because most references put it at 10^-4 ATM.
And if you want to see how stunningly advanced science was 95 years ago, http://adsabs.harvard.edu/full/1924ApJ....59..197R [harvard.edu]
(Score: 2) by RS3 on Wednesday September 12 2018, @03:03PM
Sorry, a typical case of assuming everyone knows a thing. Case in point, you may not know but when you compress a gas it gets hotter:
Ideal gas equation: PV=nRT
https://en.wikipedia.org/wiki/Ideal_gas_law [wikipedia.org]
I believe almost any matter gets hotter when compressed.
(Score: 0) by Anonymous Coward on Wednesday September 12 2018, @12:57PM (3 children)
(Score: 2) by c0lo on Wednesday September 12 2018, @01:59PM (2 children)
So, high speed collision you say.
+ Insightful on this one.
Even though, to have high speed/high temp accretion with a lowish mass blackhole - just where from the energy is coming? The heating must happen in a narrow region close to the horizon.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday September 12 2018, @02:29PM (1 child)
It comes from the same place that an asteroid falling to the earth gets its energy: gravitational potential energy. An object falling into a black hole will experience fantastic stresses as the gravitational potential is much higher at one end than the other, stretching it into spaghetti. Matter falling into the black hole forms an accretion disk, gets compressed and heated by the gravity, and radiates as a result. Since the matter will get fantastically hot in the process it'll become a superheated plasma, and naturally, charged particles accelerated by the black hole's gravity will also radiate in various ways (synchrotron radiation, brehmsstrahlung, etc.).
(Score: 2) by RS3 on Wednesday September 12 2018, @02:51PM
Is this happening on an atomic scale? And if you say "yes", then how close to the event horizon is atomic deformation beginning?
(Score: 3, Informative) by c0lo on Wednesday September 12 2018, @01:38PM
Heh, fascinating.
X-RAY SPECTRA FROM MAGNETOHYDRODYNAMIC SIMULATIONS OF ACCRETING BLACK HOLES [iop.org]
This is how the simulated black-hole disk corona looks/moves like [jhu.edu] - movie clip has some phenomena highlights.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday September 12 2018, @05:07PM
You see, black hole is a stellar mass compacted to a several orders of magnitude smaller radius then the original star.
Stars "ignite" through the similar process: gravitational attraction between center of star's mass and every single particle in its contents draws the particles closer to the center of the mass, and in the process, brings them closer together. Particles' total kinetic energy is increased through their loss of gravitational potential energy and they exchange their energy and momenta between themselves through collisions.
With ample supply of interstellar gas and other matter (dust) around black hole, the same happens when it is drawn to the same radius around the center of the mass of black hole as they are inside a star - matter gets energetic, hot, and perhaps even starts to undergo nuclear fusion, creating even more energy in the process. Light and even some particles, the light ones as well as heavy element nuclei ones may even escape away from black hole (unless they are past its event horizon). But, unlike inside a star, there is less back pressure from the matter beneath them towards the periphery ("the bottom has fallen off").