Inside galaxies there tend to reside really big black holes. These things fascinate me to no end. They range on mass from millions to tens of billions of solar masses. Our milky way’s galactic core black hole is about “about” 3.61 million solar masses, which is only mediocre compared to bigger galaxies. Even so, its event horizon is big, about 44 million kilometers. Since it’s so heavy, a lot of objects are in wild hornet’s nest orbits around it. The closest star is called S2, and gets within 120 AU of the central mass. This means that closest proximity the star moves 5 thousand kilometer per second, or about 1/60th the speed of light. Literally thousands of stars orbit Sagitarrius, and we can assume this is indeed a cosmological kitchen blender, with white dwarf stars, brown dwarfs, rogue planets, unbridled swarms of gas and asteroids and a terrifying large number of larger (100s-1000s solar mass) black holes and equally numerous neutron stars.
I am not an astrophysicist, mind you. I am clueless on mathematics. What I do is tell stories. This is a story, nothing more. I will permutate on what I have read, in particular spurred on by a recent video pertaining to a recent ‘accident’.
The centers of Galaxies are from a human perspective terrifying. Stars orbit in particularly twisted orbits, and periodically stars drift closer, and their orbits become peturbed as to stray close to the black hole. I can see this evolve in to cycles, where stars lose angular momentum because of close tidal shearing, and many stars drift more tightly packed while some stars are violently ejected. Over time the “packing” results in a feeding frenzy of the black hole, where stars and attendant white dwarfs literally detonate because of the violent energy and gas outbursts from the central feeding black hole. We call this periodical feeding phase an “active galactic nucleus” or a “quasar” depending on how we view the black hole. Edge on (and this doesn’t mean we see the galaxy edge-on – it’s possible the black hole rotates at an angle relative to the galaxy) and we see primarily radio waves of the cooling and expanding cloud lobes above and below the plane of an accretion disk. The more we look in to the central maw, the brighter and more energetic the emissions. It’s like we can watch the actual mouth and esophagus of the feeding giant and what we see isn’t very pretty – a 90 degree polar-view of a feeding black hole is called a Blazar, and we can now see the bursts of X-ray photons cast sonar-like reflections on the surrounding gas.
What happens is that when large clumps of material stray close, these clumps get disrupted when they (a) are bigger (i.e. giant stars, particularly giant stars in the red giant phase) and (b) they just happen to stray very close. Any star moving very close to a black hole moves at ridiculous speeds, probably a bit faster than the above example of S2 star – so we can see stars plow very close to the black hole region, and get torn up by the tidal force, with about the same consideration as a jelly fish gets torn up by a passing ship’s propellor. The superheavy black holes themselves barely even ‘notice’ passing stars and the celestial fireworks happening around them – for the black hole a star torn to shreds is “an ephemeral phenomenon in their outer atmosphere”. But stars are big and heavy from human perspective, and all that material is hot, moves very fast and once captured the only way is down the funnel.
The first thing to realize is that super-massive black holes spin very fast, their “surfaces” being whipped up close to the speed of light. That’s very strange, since black holes are not really ‘objects’ in a sense that makes sense to humans. They are rips in time-space, but somehow they are still assumed to rotate. I am completely off the speculating end here, but what I understand is that black holes pack completely alien super-sub atomic particles very close together. This isn’t normal matter in two senses – first it’s frozen in time, and what’s “there” is essentially frozen in free fall. The insides of the black hole aren’t normal space, with objects along motions and with definitive locations and masses – the stuff that is inside there (and that’s using the term “inside” rather loosely) is probably some kind of “frozen in time” einstein-bose condensate condensate of otherwise impossible particles in quantum-super positions relative to each other, crammed together (again, this barely covers what will be actually happening) at something close to the planck length. There will be a kind of funhouse mirror residual pattern in there somewhere of the ball of generate matter and neutrons that were racing together when some progenitor super-heavy giant very early in the universe collapsed to black hole, but we have no idea what matter does when it is “frozen in time” by the mass of the object itself. As far as we know matter isn’t matter in a timeless continuum, compressed to such density, moving at such speeds, with so much energy somehow buried between all those very angry particles. Essentially the black hole is (aside from unknowable to scientists) one big super particle with only very simple qualities – most spins (or doesn’t spin), so they have an angular energy of sorts. They have mass. These qualities determine how they interact with their surroundings.
The spin of black holes causes objects at appreciable distances (about dozens to hundreds of times their event horizon’s measurable diameter) to be “dragged” a bit in the direction of rotation. This is because space itself twists along the plane of rotation of the black hole in question, and with superheavy black holes this dragging effect is considerable. That means that stuff that starts orbiting the black hole gets twisted like a pretzel. And here is where it gets wild.
What we see on web site and in youtube videos is generally a black hole in a discrete plane with an adjacent star that billows and stretches and then “boils over” (kinda like boiling milk flowing over the edge of the pot) and spills in to the black hole in a very tidy plane of rotation. This is not what actually happens, especially with these very big holes.
When a star rips, it’s well possible a sizeable portion of the star simply moves on and “only” the outer mass of the star is trimmed off by the hole’s tidal pull. That means some stars in the galactic core will be odd stars with very high metallicity, after having suffered a very tight shave during an early encounter with the hole. These stars will probably star close and may wander too close for comfort at a later encounter. These encounters are very violent, and observed from some light years distance you might only see a star move towards the blackness of space, twist around and then – it pops like a water balloon dropped from a high building and splashes material all over the place. Stars that get ripped expand. But what’s more relevant, they get ripped in an explosive fashion, often at a violent angle relative to the black hole. Yes, the inside of the vortex will exhibit the characteristic funnel, but do realize these funnels will be very big relative to the black hole. Yes the insides of these high friction environments will attain fusion heat, and will be like a hydrogen bomb detonation per kilometer of space per millisecond. Or something like that.
What I find so fascinating is that over large distances (hundred to thousands times the event horizon) material that orbits and falls in may flow in intricate and bewildering arcs. If a black hole has an adjecent black hole, it gets really weird. I am in love with these particular set of animations, which suggest very strongly that these systems may last quite a while (weeks? months? years? centuries? No idea) and that these systems may have outside regions of orbiting material where, in some distant future date, humans may have (heavily shielded) observatories that can actually survive long periods in the shadow plane of these accretion disks. At a healthy distance I assume these disks may be “cloudlike” and may have ring shape structures somewhat reminiscient of saturns rings.
But close to the black hole the material wants in, because of friction, and piles up in to a donut. The inside of the donut is hot, and material wants to move out because of explosive and radiative pressure. These regions I would describe as the “cauldron” of the black hole, as it comprizes a compressed region of outflow and containment. Again, the black hole itself could be barely visible “at safe distances”, a minute black fly in a hurricane, obscured by encapsulated clouds, electrical storms, plasma and a light so bright it would vaporize a massive structure of sheet metal within thousands of astronomical units distance in mere minutes.
For some reason the outflow of energy is most far-reaching along the polar axis of the black hole, and the spray of ions and particles and photons bursting from the north and south of a quasar is so energetic that the crazy firehouse spraying through an adjacent galaxy can rip the targeted galaxy visible to shreds. This shows how energetic these bursts are, how far they reach and how uncannily narrow they remain even at an absurd distance – tens of thousands of light years. Imagine that, a universe where “accidentally” a nearby quasar destroys billions of star systems (and almost certainly quite a bit of planets with higher organic life) and sterilizes them in to cosmological irrelevance.
Supermassive black holes don’t eat everything they are served – ‘they are very sloppy feeders’ is the most often used quote. Material that explodes out bursts up like a galactic geyser and rains back on to the plane of the galaxy, and may actually spur on star formation in a wide region.
What I would love to see in my life is an SF movie of stuff happening near the black hole at the center of a galaxy. With Star Trek style stellar cartography depicting the maelstrom of black holes, neutron stars, white dwarfs, supergiants (and no doubt cosmic objects we can’t even conceive of with today’s scientific understanding) churning around the center of gravity, a series of angled and overlapping accretion disks (plural) of an imminent quasar radiating out half a light year in 3 dimensional arcs and gas filaments. Imagine an interstellar war over an extremely scarce resource (say, these cauldrons are the only spot in the galaxy where large amounts of stable elements with atomic numbers far above 120 are formed) and where several factions war over access to these harvests. Imagine interstellar factions move around with intricate FTL vessels in such a hellish starscape, moving across deadly regions of space, interspersed with thousands of bottomless gravity wells. It would be a very interesting vision indeed.