Simulation Explains Supermassive Black Holes

Spy der Mann writes "Using a new computer model of galaxy formation, researchers from Carnegie Mellon University have shown that growing black holes release a blast of energy that fundamentally regulates galaxy evolution and black hole growth itself. According to its creators, 'the model explains for the first time observed phenomena and promises to deliver deeper insights into our understanding of galaxy formation and the role of black holes throughout cosmic history'. Hi res pictures and animations (divX) are also available."

Re:Hmm

[Entrope]

So your saying that black holes release energy that help themselves grow? Does this just loop forever?

It says "regulate," not "accelerate" or "encourage." Even in more prosaic domains like Earth-bound policy, regulation often limits what is done rather than broadening it. If you Read The Fine Article, one of the authors is quoted explaining this outpouring of energy pushes back on infalling mass.

On a different note, perhaps as a Carnegie Mellon alumnus I am biased, but I find it interesting that the top

Re:Hmm

[mbrother]

Astronomy does pretty well with women, at least compared to other hard sciences. At the undergraduate level, it looks to be close to 50/50. Last year I think we had more female applicants for our summer REU program than males. We're going to admit more women than men into our graduate program this year, too. At the more senior levels, there are fewer women, but the numbers more or less match the historical demographics. My PhD advisor was female, and I have lots of female collaborators and a female grad student. Di Matteo isn't too old -- my generation, 30s. Physics, on the other hand, is still having its problems...

Re:Hmm

[grozzie2]

Physics, on the other hand, is still having its problems...

This is not for lack of trying tho. Most of them headed that way ended up taking jobs on the psychic hot line, but hey, it was only a minor spelling mistake...

Re:Hmm

[fireboy1919]

There's this interesting distinction in my areas (Computer Science and Computer Engineering). All the women in my graduate program were going into cognitive science or databases. None went into anything else.

Not that I blame them; I didn't go into any of those things either. It's strange, though, because those are the only two areas offered that don't have any hard math.

Re:Hmm

[IWannaBeAnAC]

But then, pure maths seems to be doing OK with women, at least at undergraduate/early graduate levels. So its not maths per se that's the problem. Is it simply inertia? Maybe astronomy 'simply' achieved a critical mass of women, so new female students don't feel like they're joining a club of crotchety old men?

Re:Hmm

[-rgtm-]

Then again, it's not surprising to see a large drop in male students, considering how hostile and anti-male an environment so many universities have become.

Feminist bigotry is taking its toll.

Re:Hmm - statistics for women in astronomy

[Anonymous Coward]

The following website gives the hard numbers for whether the women at senior levels matches the historical demographics. It gives the percentage of women who receive PhDs compared to faculty positions for 1992, 1999 and 2003 at many different universities. Grad students in 1992 should have become either full professors or assistant/associate professors by 2003 (depending on when they received their PhDs). Check out the percentage of women who got PhDs in 1992 and compare it with the percentage of women f

Re:Hmm

[tm2b]

perhaps as a Carnegie Mellon alumnus I am biased

I suspect that the number of us reading Slashdot is pretty scary...

but I find it interesting that the top billing went to a woman.

From Carnegie Mellon, where "the men are geeks, and what are women?"

You See...

[Uber Banker]

1. They made a model which seemed nice from a theoretical basis.
2. They simulated it.
3. They got a massive residual
4. They thought "oh crap, that didn't work, how can we justify our funding... lets say it fundamentally affects the evolution of the universe and formation of black holes, that should double our funding!"
5. Profit!

Reflecting the /. effect?

[bagel2ooo]

Well, after the incident with the British Royal Navy and the 38MB Powerpoint file linked to the front page. Now we get to see if the /. effect will cause the packets to coalesce and turn their server into a matter crushing supermassive black hole itself. I guess 22MB DivX is better than linking MPEG. :)

Coral Cache Mirrors

[Agret]

Medium Image [nyud.net]
Large Image [nyud.net]
Medium Quality Movie [nyud.net]
High Quality Movie [nyud.net]

Could we Makeup our diffrence?

[Kirkoff]

I always thought that Cosmetics were a black hole for money.

Since nobody uses Coral Cache

[Agret]

Here is another mirror for the Medium Quality Image [img161.exs.cx]

animations

[selderrr]

/me thinks they used iTunes screensaver for this :-)

Cool

[mboverload]

Even a non-nerd HAS to admit this is really, really cool.

At least I think so. Seriously, I think everyone loves black holes.

Re:Cool

[piquadratCH]

Seriously, I think everyone loves black holes.

No. They suck.

Re:Cool

[Liquidrage]

"...have shown that growing black holes release a blast of energy"

And apparently they blow as well.

Re:Cool

[Urkki]

• • Seriously, I think everyone loves black holes.
  
  No. They suck.

But doesn't that just make them more fun to be with, and easier to love?

Re:Cool

[AstrumPreliator]

I don't know about that. My last girlfriend told me her black hole was "off limits".

Re:Cool

[Anonymous Coward]

I don't know about that. My last girlfriend told me her black hole was "off limits".

I can see why. Space tends to warp at the event horizon and time seems to slow down from the observer's standpoint. Think about it, think if it was your black hole.

Re:Cool

[Liquidrage]

That's because you have never paid for the upgrade and are trying to access disabled features in the shareware version. If you buy the full version of "Wife" then all the features are unlocked.

Some people are really talented though and if you work at it you can unlock several features of Wife in the Girlfriend version including the back door access.

However if you do upgrade to Wife remember that you are actually just paying for a license that allows you to use Wife and you will often have to shell ou

Re:Cool

[c0p0n]

...I think everyone loves black holes.

Speak by yourself! Do you also love Hairy Quasars?

Pretty Interesting

[mbrother]

This is my area of expertise, from the observational side. I've just finished writing a proposal (due today!) to observe "post-starburst quasars" in the infrared with the Spitzer Space Telescope. These are quasars that still show clear signs of massive starbursts, observations that can in principle test simulations like the ones discussed in the article. I've seen Di Matteo give a talk on this topic a year or two ago, and she strikes me as very good. I'm going to have to check out the new work closely -- I have suspicions that their explanation will fail in some details. But that's what makes science fun, finding the problems with ideas and fixing them, or forcing everyone to move on.

Re:Pretty Interesting

[js7a]

so, how long are quasars resulting from supermassive black hole collisions expected to last?

Re:Pretty Interesting

[mbrother]

There are limits to quasar ages based on demographic arguments (the relic holes we see today compared to historical quasar activity and assumptions about the efficiency of the matter to energy conversion). The upper limit is on order of 100 million years or so. I know the timescale for "blowing out" gas/dust on Galactic scales from a powerful quasar is much shorter than that, more like 100,000 years, so I'm going to have to see the jounral article and see what they're saying in this paper. Big difference between those two numbers. Keep in mind that even 100 million years is relatively short compared to a unverse age of 13.7 billion years and may be the "short" timescale discussed.

Re:Pretty Interesting

[js7a]

Thanks. Let me ask some more: What are the dynamics of such a quasars that last for so long? When the big black holes collide, do they deform, splatter into pieces, start spinning and flatten, or what? What would such a quasar look like up close (discounting the instant subatomic vaporization....)?

Re:Pretty Interesting

[mbrother]

No, the black holes CAN'T splatter into pieces. They're too massive, their gravity too strong. All the "crap" around them -- gas, dust -- that is the fuel of the quasar -- that stuff surely does spew all over. The basic accretion process, when things settle down and merg, is for that material to form a flattened disk. When you see a quasar, it is the intense radiation from this hot disk that does all the shining. The black hole just provides the gravity. There may also be relativistic jets shooting out the spin axis, but their formation is not well understood. Neither are the less collimated outflows from around quasars (one of the reasons I'm suspicious about their results -- they're dealing with a broad brush and could be right on that level but we surely don't understand a lot of the details even on an empirical, observational level).

I've got some lecture slides on active galaxies (powerpoint) up at my astronomy website. Look at: This link [uwyo.edu]. There are some some real images, and some artists renditions, you might like. I've just used the powerpoint web format, so it looks crappy in anything but explorer. Sorry.

Re:Pretty Interesting

[mbrother]

As I understand it Hawking radiation is completely negligible from supermassive black holes. I would imagine that the event horizon scale is so large compared to anything really freaky that the distortion doesn't make that much of a difference.

Re:Pretty Interesting

[mbrother]

I'll add that if you go to www.mikebrotherton.com, the cover art to my first novel Star Dragon shows an accretion disk around a white dwarf star. It isn't quite the same thing as a quasar, but it is similar and it's nice artwork (by Stephan Martinere, who deserves his name mentioned).

Re:Pretty Interesting

[Ev0lution]

This is my area of expertise, from the observational side

This was my area of expertise too, although I've now left astronomy. I worked indirectly with Volker Springel, who is extremely good (his simulation code, GADGET, was depressingly better than mine!). The bit that's new is the treatment of radiative transfer, which is extremely hard to model (the full treatment is a time-dependent function of six variables, so you have to simplify it somehow). Doing it well is an achievement in itself, but it's also where the numerics are likely to be wrong. The non-radiative aspect of the simulations isn't new (I did similar simulations for galaxy clusters in my thesis, and although I did them better - at the time - it wasn't new then).

Re:Pretty Interesting

[vacuum_tuber]

A genuine Science Babe! I wanna marry her!

A great step for xscreensaver

[Jammet]

Now we can replace the galaxy screensaver with this calculation, and it entertain even more!

Fears put to rest

[DrKyle]

I've always wondered if one day everything will get swallowed up into a super massive black hole, it's nice to read an article explaining that black holes power quasars which actually push matter away from the black hole. At least temporarily (some billions of years?), I guess eventually gravity will win out over quasar wind.

Re:Fears put to rest

[m50d]

Eventually the accreation disk (that does the radiating) will all get sucked in, and then there will be no more "wind", so more matter can be pulled in.

Re:Fears put to rest

[p3d0]

Dude, you're living in a black hole.

Imagine a sphere of matter of a given fixed density D. Escape velocity is proportional to sqrt(M/r) for mass M and radius r. Since M=Dr^3, escape velocity is proportional to r*sqrt(D). Therefore, no matter how small D is, you can find a radius large enough to make the escape velocity exceed the speed of light.

Given estimates for the (very small) average density of the observed universe, you get a number like 10e10 light years [arxiv.org], which indeed matches pretty closely (

Drugs are bad, mkay?

[stuffman64]

Do not watch the video after eating acid.

You've been warned.

More Information

[NEOtaku17]

Here [arxiv.org] are tons of the most recent research papers on black holes. Definitely an good read for anyone with an interest in physics.

Don't dis the MC or the E.

[ABeowulfCluster]

Mass to Energy to Mass.... Einstein Told Ya so.

Resolution espected

[FrenchNeal]

They should have released images in 1024x768, 1280x1024 etc... to make it better wallpaper!

Bold claims

[ralphclark]

Surely the word "may" belongs in there somewhere?

Re:Bold word choices

[tm2b]

Why, who's giving permission?

The word "might" might have a place, though.

Re:Bold claims

[oliverthered]

The problem with 'modern' physics it that a bunch of people come up with a bunch of mathematical equations that try to explain what they may be seeing.

It's not that amazing that someone says, hey we looked at black holes, done that math and wow our model matches out observed data (well to with in 99% +- 2%).

scientists are often hunting the answers to equations that they know are partly wrong to start with, what the chances of finding a higgs boson vs a fluke?

Re:Bold claims

[ralphclark]

Sure, I understand how that works. It's just that some scientists seem to get a bit carried away with their model; they seem to forget it's only a model composed of incomplete data and imperfect equations.
eg. some planetologists got a bit of a shock when they discovered the surface of Titan wasn't exactly as they'd imagined it.

Re:Whoa, massive blackhole...

[Flendon]

i always have wondering since nothing can escape then why is it emitting something out of it? Just a thought.

The blackholes don't actually emit anything. The accretion disk is what does the emitting. Imagine water going down a drain. Most of the matter approaching a blackhole is not on a direct collision course but rather the blackhole sucks it close where it spirals downward. The spiraling excites the atoms creating huge bursts of energy, sometimes enough to blast nearby matter out of the gravitational field.

Re:Whoa, massive blackhole...

[Flendon]

The X-rays are also produced as a part of the large burst of energy I mentioned.

Re:Whoa, massive blackhole...

[mbrother]

The origin of the X-rays are not well understood, but are thought primarily to come from upscattering of thermal photons in a very hot atmosphere above the accretion disk. All the light basically comes from the stuff right around the black holes moving at relativistic speeds, not the black holes themselves.

Re:Whoa, massive blackhole...

[Baudelaire76]

The blackholes don't actually emit anything. The accretion disk is what does the emitting.

Actually, black holes do emit. It's called Hawking radiation. But you're right in that what we see is coming from the accretion disk.

BitTorrent Link for Hi-Res Video.

[templest]

Just in case, I made a BT link for the video and have it running in the background. So if the site does get SlashDotted, you know where to get it. :)
http://s2.isohunt.com/release.php?id=10330 [isohunt.com]

Interesting pictures

[Anonymous Coward]

There are interesting pictures on Google Images when you search for big black holes. Science is fascinating.

Implications for our own galaxy?

[kcbrown]

If I'm not mistaken, the Milky way and the Andromeda galaxy will collide (or have a near-miss, I'm not sure which) about a billion years hence.

If both galaxies have black holes at their centers, and the simulation is correct, then I have to wonder what the consequences will be for life within either galaxy, as I would imagine the burst of radiation from the collision of the black holes (and the resulting quasar) will be deadly.

Anyone wanna chime in with some numbers?

Maybe the Pierson's Puppeteers have the right idea after all...

Re:Implications for our own galaxy?

[mbrother]

The high supernova rate resulting from the burst of star formation is likely more of a problem than a central quasar, especially since the star formation can take place outside of the Galactic center. I give my intro astronomy students a problem to computer what the Galactic core would look like if it was a quasar and there was no intervening gas/dust (a really big if, since there is a lot of obscuration now).

Quasars can be 1000 times more luminous than an entire galaxy. The absolute magnitude of such a luminous quasar would be about M = -28.5. If the black hole in the center of our galaxy became a quasar, and obscuring gas and dust did not dim it, what would the apparent magnitude of the galactic core be? Think about the answer and what that would look like in the sky.

The answer is a magnitude of -13.9, about the same as the full moon. It would be more concentrated that the light of the moon, and you'd be able to see it in the day time. But, as I said, intervening gas/dust would diminish it's light, and the Milky Way and Andromeda do not have black holes massive enough to shine as brightly as my example. Our atmosphere would also be there to protect us from X-rays and UV, much as it does now.

Sounds interesting...

[Zangief]

I give my intro astronomy students a problem to computer what the Galactic core would look like if it was a quasar and there was no intervening gas/dust (a really big if, since there is a lot of obscuration now).

What program and model do they use to do this?

Re:Sounds interesting...

[mbrother]

This is just a simple calculation based on the distance to the galactic center and the given absolute magnitude. You work it out in a couple of lines of math. This is for my non-major course and doesn't involve MHD simulations!!!

Re:Implications for our own galaxy?

[sploo22]

A collision between galaxies is not exactly as dramatic as you seem to think it would be. Remember, stars are light-years apart. Actual collisions between stars would be very rare, and unless the black holes come within an incredibly tiny distance they would just slingshot around each other in a hyperbolic orbit and keep going. The real issue is that large numbers of stars would be flung off into space in the process, but I'd say that if there are any humans still alive then, a boring night sky is something

Re:Implications for our own galaxy?

[kamikasei]

This is gone over in one of Alastair Reynolds' books - Redemption Ark I believe it was. From what I can remember the main problem wasn't colliding stars but colliding gas clouds and such, prompting new star formation, leading quickly to supernovas, which due to their size or location or both would basically sterilize most of the galaxy. Not quite a boring night sky...

Re:Implications for our own galaxy?

[sploo22]

I was referring to what would happen if the sun got catapulted out of the galaxy, given that all the stars we can individually see are within the Milky Way. I hadn't considered effects of gas clouds; thanks for pointing that out.

Re:Implications for our own galaxy?

[Pedrito]

If I'm not mistaken, the Milky way and the Andromeda galaxy will collide

You are correct. And a simulation of that can be found here [utoronto.ca] in mpeg format.

The Origin of the Black Hole

[rinkjustice]

I'm pretty sure the last Disturbed album, Believe,
sucked so bad the graviational pulls caused a black hole.

Pretty terrifying and distructive. The album I mean.

Weapons of Mass Suction

[gelfling]

Quick let's declare war on it.

Re:Weapons of Mass Suction

[quarkscat]

Don't you think one "black hole" is enough?
It isn't as if the USA doesn't already have
a "black hole" to piss blood and money down.

That aside, perhaps black holes are God's
equivalent of a clothes dryer - instead of
eating socks, it eats galaxies.

Sorta...

[Sensible Clod]

actually, black holes are where God divided by zero.

This is a simulation, right?

[javabozo]

So now you can announce results of a Simulation and have it be taken seriously? I want to announce that according to my simulation, most simulations are not worth the paper they are written on.

Re:This is a simulation, right?

[javabozo]

I want to simulate a relply to my post. "What are you stupid or something? That argument is not [orthogonal] | [relevant] | [green] compared to the original thesis, which was [humans are not extraterrestrials] | [blue food is rare] | [my simulation shows that early observational items like quasars (or substitute watermelons) are not at all as interesting to chief financial officers as they are to [nerds] | [programmers] | [knee biters].

Re:This is a simulation, right?

[GOPMacDaddy]

I couldn't agree more and wrote about this in my blog. There are way too many unknown variables to make this mean anything. I can't believe anyone takes any of this seriously. If I ran a simulation of my financial situation and the simulation shows that I'll be a millionaire in ten years, can I start claiming it now? No. Why? Because there are too many unknowns. The only way to know anything about blackholes is to get near one and I'm afraid we haven't done that yet. They could run simulations all day long

Re:This is a simulation, right?

[mbrother]

Simulations are a valuable area of investigation in most modern sciences, including astronomy. It's a very reasonable approach and complementary to observation. Basically, think of it as an expression of a theory, that makes specific predictions that can be tested against observation. Their simulation, based on some assumptions and our current physical understanding, has to match observations or we know they did something wrong. To the extent the simulation matches observations, and continues to pass ob

Re:This is a simulation, right?

[mbrother]

At the risk of belaboring the point, I wanted to mention how important Toomre and Toomre's galaxy simulations were in the early 1970s. We could see interacting galaxies out there, with long drawn out tails of stars, that looked really strange. It wasn't until they did numerical simulations with many stars moving according to gravity that we could really be sure we understood what was going on. These simulations produced the same sort of odd features very naturally, the result of gravitational tidal force

No duh

[alex_guy_CA]

Am I missing something, or is this research fundamentally obvious. "Big galaxies contain more dust and make more stars, small galaxies have less dust and less stars." Gee wiz, that just stretches the limits of possibilities.

Re:No duh

[mbrother]

You're missing something. The work is trying to explain a rather tight relationship between the masses of the central black holes and the masses of the stars in the galaxies. The black hole is always about 1/1000 of the galaxy mass. Why 1/1000? Why not 1/100 or 1/10000? Why so steady for ALL galaxies? It's THAT observation that makes this research of interest, because they've apparently found a quantitative way to explain this fundamental relationship.

What an interesting coincidence...

[Spy der Mann]

Remember the last article on /. [slashdot.org] about a star flunging away from our own galaxy? It said that could only be possible if the Milky Way orbited around a SM black hole. Which led to the discussion about the role of black holes in galaxy formation.

What strikes me is that just a couple of days after this theoretical discussion [slashdot.org], the scientists at Carnegie Mellon come up with a model that predicts exactly the same theory.

It all points to the theory being actually true.

iHole?

[Doc Ruby]

When do we get our personal rotating cylindrical black holes? They make nifty time machines!

Re:iHole?

[rob_squared]

I'd bet something like iHole has already been trademarked by another industry.

Evolution?

[null etc.]

Using a new computer model of galaxy formation, researchers from Carnegie Mellon University have shown that growing black holes release a blast of energy that fundamentally regulates galaxy evolution and black hole growth itself

Keep in mind that evolution is just a theory, and must be critically examined.

I myself prefer to believe that God himself is pushing around all the energy by hand.

Energy...

[TapeCutter]

It's not God, it's the giant turtle farting.

Re:Energy...

[Dabido]

" It's not God, it's the giant turtle farting."

Blasphemy! Great A'Tuin doesn't "fart", she's a lady turtle. Ladies do not do that sort of thing.

Of course, it might be the auditors releasing wind as they disappear. A rincing of winds maybe?!

Cornell and Caltech Work

[karvind]

Similar work has been carried out by Cornell and Caltech under Saul Teukolsky [cornell.edu] and Kip Thorne [caltech.edu]. Cornell's Black Hole Numerical Group Homepage [cornell.edu] has more details about simulating collision of black holes and other relevent information.

Black Holes kick ass

[Shoeshine-X]

This is some sweet information.

Watch lots of simulations!

[JThundley]

/usr/lib/xscreensaver/galaxy