How do supermassive blackholes form?

[Cmac22]

so i was looking online for info into this question and there wasnt really a whole lot. most of the stuff i found was a bit old and more of speculation. i suppose its mostly speculation anyways but i was curious if there was any newer info about them. how would something millions and sometimes a billion times the mass of the sun come into being?

 

My obviouse guess would be that the occasional planet or star would get to close and get pulled in, along with all the gas around and such. but how often is this? i suppose over millions or billions of years it happens.

 

But the biggest black hole im aware of is about 4 billion times the mass of the sun. that means that in a universe 14 billion years old, if it did form then, it would need to grow by one billion solar masses every 3.5 billion years. that means one new solar mass pulled in every 3.5 years on average. does that seem unlikely or is that possible... i guess it must be but... where does all that mass come from!?

 

i was just reading an article about the milkyways supermassive black hole from 2003

 

"Only hints of spin have been noted from supermassive black holes, each of which is thought to form and evolve hand-in-hand with the development of the galaxy in which it sits."

"depends on the curvature of space around the black hole, which also depends on how fast the black hole is spinning. A spinning black hole drags space around with it and allows atoms to orbit nearer to the black hole than is possible for a non-spinning black hole"

 

http://www.space.com/scienceastronomy/mystery_monday_031124.html

 

this is another one from 2005 talking about its size

http://www.space.com/scienceastronomy/051102_black_hole.html

 

 

one question i have from reading these is does spin effect its gravitational pull. in the second quote there it talks about. how does the spin effect its pull? and what causes this spin? is it the fact that an entire galaxy is spining around it or something else?

 

alot of stuff in there your time and comments are greatly appreciated!

[a Clown]

I think it's the same way, just a larger star...

[iNow]

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/010509a.html

 

Recent studies indeed show that perhaps all galaxies with "bulges" have a supermassive black hole, which contains about 0.2% of the mass of the bulge. Depending on the size of the galaxy, that might translate to a few million to a few billion times the mass of the sun. This fraction, 0.2%, is too small for the supermassive black hole to control the motion of all the stars in the bulge. On the other hand, these masses are indeed too large to have formed from a single star.

 

So how did they form? We don't have a detailed answer yet. We do know that gravity can act in a catastrophic way. If you have a region of enhanced density (say more stars per volume than in surrounding regions), its gravity will be stronger, which tends to increase the density more ... .

 

The recent finding, that the mass of the supermassive black holes is closely related to that of the bulge, shows that the formation of supermassive black holes is also closely linked to that of the host galaxy. That is, they (the galaxies and the supermassive black holes) probably grow together.

 

 

Much more detail available here:

 

http://chandra.as.utexas.edu/~kormendy/stardate.html

 

 

 

Black Holes as massive as a billion Suns are thought to form as galaxies collide and merge. This computer simulation follows the interaction between two large disk galaxies. Blue represent gas and red the stellar distribution. Each galaxy starts with a Black Hole at its center. The two Black Holes accrete large amounts of gas as they sink at the center of the collision remnant. Every second represents 70 million years.

 

 

http://adsabs.harvard.edu/abs/1998AAS...192.4301S

We propose that Gamma-Ray Bursts (GRBs) are related to the formation of supermassive black holes at centers of quasars and galaxies. The formation events associated with these black holes have a much higher gravitational energy release than conventional solar mass scale GRB candidates. They therefore can easily meet the energetic requirement of the observed GRBs. To yield the observed GRB event rate, the amount of baryons incorporated into the progenitors of these black holes as a fraction of the total baryons in our universe is about 10(-4) . This fraction roughly matches the masses of supermassive black holes at the centers of galaxies as a fraction of the total baryonic mass of the host galaxies. If the progenitors are relativistic star clusters, as commonly proposed, star collisions during the formation of the supermassive black holes may give rises to the rich and bursty time structure observed in GRB events.

 

 

http://chandra.harvard.edu/xray_sources/blackholes_sm.html

Recent research, including results from Chandra (see 3C294, Perseus Cluster, NGC 4636, Centaurus A) suggests that galaxies and their black holes do not grow steadily, but in fits and starts. In the beginning of a growth cycle, the galaxy and its central black hole are accumulating matter. The energy generated by the jets that accompany the growth of the supermassive black hole eventually brings the infall of matter and the growth of the galaxy to a halt. The activity around the central black hole then ceases because of the lack of a steady supply of matter, and the jets disappear. Millions of years later the hot gas around the galaxy cools and resumes falling into the galaxy, initiating a new season of growth.

[Klaynos]

I think it's the same way, just a larger star...

 

There is a physical limit to how large a star can be, the Eddington limit, it is due to the photon radiation pressure forcing the star to loose mass, it's about 100 solar masses.

 

http://en.wikipedia.org/wiki/Eddington_limit

[Cmac22]

thanks for the links inow. but yea i dont think a star could get even close to large enough. also i found that the largest know black hole is actualy around 11 billion solar masses. thats big heh... i suppose depending on the size those theorys seem reasonable. i guess the biggest black holes would be from galaxys that merge into several galaxys probably. and the smaller ones possible from just their own galaxy or one more.

[Dark matter]

Black holes form from supernovae, and they get bigger because they build on themselves, for instance once you "suck in" another celestial body, then you gain more gravity and keep on gaining more and more mass and gravity. Correct me if I'm wrong.

[Klaynos]

Black holes form from supernovae, and they get bigger because they build on themselves, for instance once you "suck in" another celestial body, then you gain more gravity and keep on gaining more and more mass and gravity. Correct me if I'm wrong.

 

That is how stellar black holes form, not supermassive.

[Zephir]

...How do supermassive blackholes form?..

By my private opinion, most of massive black holes are of primordial origin, 'cause they were created just during universe inflation as so called quasars, i.e. "white holes" with excessive matter/energy, which has evaporated gradually into galactic clouds, surrounding the cold remnants. The animation on the left illustrates the vacuum condensation, which is supposed to be similar to crystallization of supercooled/saturated fluid, the picture on the right is the resulting foamy structure of dark matter, in the nodes of which the largest black holes and gallaxies are residing.

 

 

Such hypothesis could be tested, if we'll found the central black holes of most large gallaxies of the approximatelly same size, for example. After then it will be evident, the size of cold remnant doesn't depend on the amount of surrounding matter, but the thermodynamical equillibrium between matter and radiation. Another evidence is, the most distant / oldest qusars observed so far are surprisingly well developed, but no visible matter can be observed around them. Here are many other indicia for such model, which we can dispute in detail, if somebody will be interested about it.

 

This model doesn't require, all matter was originated from black holes, though. The smaller ones can still appear by gradual accretion of finelly divided matter, i.e. by normal way of "classical cosmology". Currently its difficult to say, which portion of matter has appeared in finelly divided state and which was evaporated from supersaturated quasar droppled subsequently. By my opinion, the smaller gallaxies are spherical and without central black holes, because they never pass the evaporative period of central black hole, which is followed by formation of jets and "fountain effect", which makes the gallaxy a flat and rotating disk.

[Cmac22]

it seems like you have some interesting ideas there. i didnt understand some of it on the first pass but ill look over it again when i got more time.

 

thanks for the input!

[iNow]

Cmac,

 

Just recall, while those are definitely interesting ideas, they are (at this point) speculations and not supported or accepted by currently active researchers in the field. In other words, thought provoking, but should not be included on any assignments or papers where you care about your grade and/or feedback.