Monster Black Hole Busts Theory

Genocaust writes "A stellar black hole much more massive than theory predicts is possible has astronomers puzzled. Stellar black holes form when stars with masses around 20 times that of the sun collapse under the weight of their own gravity at the ends of their lives. Most stellar black holes weigh in at around 10 solar masses when the smoke blows away, and computer models of star evolution have difficulty producing black holes more massive than this. The newly weighed black hole is 16 solar masses. It orbits a companion star in the spiral galaxy Messier 33, located 2.7 million light-years from Earth. Together they make up the system known as M33 X-7."

Comments

In the Dark

[ArcherB]

I wonder if this is where all that "dark matter" is. Scientist keep talking about how there is so much more matter than what we can detect. Well, we haven't been able to detect this until now. How much more is missing, I wonder.

It amazes me at how much we DON'T know.

Re:In the Dark

[ArcherB]

Technically, there is a difference between dark matter and and matter so dense its dark. Think of dark matter as "matters at hand in the universe in which we're still in the dark." On second though, "terra incognita" is a much better analogy.

Well, I wasn't talking about black holes being made from dark matter, but like you said, matter we were "in the dark" about or matter than we are unable to detect. Well, evidently, we were in the dark of about 75% of the matter than can exist in black holes. It wasn't until recently that we learned of super massive black holes in the center of every galaxy. All this is matter that we were in the dark about. How many more black holes are there that we don't know about? How much larger are they than we thought they could be? How much more stuff is out there that we can't detect that is perfectly reasonable, easily explained and not at all weird or mysterious, for example solar systems where the center body is simply not big enough to start the fusion process and thus remains dark and unknown to us?

I just keep hearing how dark matter is this uber-mysterious stuff that makes up a majority of the universe and we have no idea what it is. Well, maybe it's something simple like the examples I gave above.

What passes for science on Freerepublic.com

[Anonymous Coward]

To: NormsRevenge Massive black hole enters the record books (Messier 33) AFP on Yahoo ^ | 10/17/07 | AFP ... Astronomers have found the biggest stellar black hole so far, a monster with a mass 15.65 times that of our Sun, lurking in a nearby spiral-shaped galaxy. ... Another category of black holes are "supermassive" holes, spotted at the centre of galaxies, that have masses millions, even billions, times that of the Sun. I'm confused. What's the big deal? 12 posted on 10/17/2007 7:55:34 PM PDT by LoneRangerMassachusetts (The only good Mullah is a dead Mullah. The only good Mosque is the one that used to be there.) [ Post Reply | Private Reply | To 1 | View Replies | Report Abuse ]

Re:Supermassive black holes

[StikyPad]

If theory says that black holes beyond 10 solar masses cannot form, how do they explain the conjectured supermassive black holes

Like This.

Or, more pedantically, black holes may never form at all from the point of view of an observer outside the event horizon.

Computer models of Supernovae

[confused_demon]

For this discussion it's worth keeping in mind that current computer models have real problems actually getting supernovae to explode. At one point it was so bad that I heard someone say, "If it weren't for the fact that we occasionally observe one explode, I would assure you that they cannot." It's only been in the last couple of years that someone has made a computer model that actually did it.

Re:Computer models of Supernovae

[Leperous]

"It's only been in the last couple of years that someone has made a computer model that actually did it."

Not true. As a numerical relativitist, I can tell you that no decent 3D simulations of supernovae currently exist.

Half the problem is that the physics is simply unknown - is it sufficient for your model to contain rotation, magnetic fields, and what about the equation of state of the plasma? Neutrinos are also thought to play an incredibly important role in the supernova explosion mechanism, and subsequent nucleosynthesis (and other processes) that go on during the supernova event itself. The other half is the sheer computing power to evolve your equations over decent time scales with enough resolution, not to mention making sure the numerical methods you employ work.

There are plenty of groups who are currently working towards 3D evolutions without any neutrino transport, and I think some people have done neutrinos in 1D. Try checking out some of the work by Leibendorfer, for example.

A quick run down of the supernova event though, since the article skims over it very lightly: heavy elements gradually build up at the core (nickel and iron especially), and nuclear fusion shuts down due to their high binding energies. As a result, outwards pressure ("thermal support") is lost, and at some critical moment the core will rapidly collapse onto itself (on a timescale of less than a second) as gravity becomes the dominant force. The outer layers will also in-fall onto this collapsing core.

Depending on the mass of the star, we'd expect the core to collapse into some kind of 'proto' neutron star, or straight into a black hole, if it's massive enough. In the case of the former, neutrinos escaping from the cooling central proto neutron star deposit energy into the outer layers, and drive the actual supernova explosion-event. In the case of the latter, I'm not sure that you'd actually see much of a supernova since neutrinos wouldn't be able to escape from a black hole - or at least the explosion mechanism would be different. There is an 'intermediate' option though: a proto neutron star that later on collapses into a black hole, from the still in-falling outer layers. If this happens you'd expect both a black hole, and pretty violent supernova to boot.

I'm not sure about the numbers presented in the article either. Typically, stars above 8 solar masses will collapse and create a supernova and neutron star remnant. Stars over 20 solar masses should form a neutron star which later collapses into a black hole (as is the case here). Stars over 50 solar masses or so will probably just collapse straight into a black hole, with unknown supernova mechanisms.

Re:Supermassive black holes

[Tablizer]

I was wondering though, is it possible that a black hole of this mass could me produces in a trinary solar system where two black holes merge, in this case leaving you with a 16 solar masses and orbiting the remain star?

If I am not mistaken, the largest stars tend not to be binary/trinary. Once the mass gets past a certain point, it upsets the harmonics needed to make doubles and triples. However, I can't find any verification of this mentally rusty snippet of info.

Re:Supermassive black holes

[ozbird]

A stellar black hole that's so big it shouldn't be possible for it to have been created by the usual supernova, and in a region of space sufficiently vacant to rule out the gobbling theory, is what is being puzzled over.

The region of space is vacant now - it doesn't mean that it was when the black hole was feeling peckish.

Re:Supermassive black holes

[gomiam]

Reading the article, it seems that the computer models of supernovas would strip all those supermassive planets of their gaseous layers, if not blow the planets themselves away. The problem isn't the black hole being that big (that's a symptom), the problem is how do you make a star go nova "softly" like this one would have done.

And, yes, it seems the simulations are wrong. That's why it's hard for the current nova theories (read models) to create a black hole this big.

Re:Supermassive black holes

[osu-neko]

Yes, it's extremely hard to figure out how what you just said could possibly happen. If it was a ternary system, that means the three stars were in stable orbits. One forms a black hole. If no mass were lost, everything would remain in the same stable orbits. If mass were lost (which is almost certainly the case -- supernovas tend to throw off a lot of mass), then the star that becomes a black hole now has *less* grip on its companions than it did. If it doesn't lose them entirely, they should at least shift into more distant orbits. When a star becomes a black hole, it becomes much LESS likely to gobble up its neighbors. If it didn't gobble them up before it collapsed into a black hole, it almost certainly isn't going to do so afterwards.

Re:Supermassive black holes

[Dragonslicer]

So, for instance, a 1 second-lived black hole has a mass of 2.28 × 10^5 kg Which means that in order to create such a black hole, we'd have to be able to cram 10^5 kg of mass into a singularity. That's a pretty small mass in the realm of astronomy, but it's a pretty damned big mass in the realm of particle physics.