Astronomer Discovers Upper Mass Limit for Black Holes
September 5th, 2008
Natarajan found that ultra-massive black holes, which lurk in the centers of huge galaxy clusters like the one above, seem to have an upper mass limit of 10 billion times that of the Sun. (Credit: NASA)
There appears to be an upper limit to how big the universe’s most massive black holes can get, according to new research led by a Yale University astrophysicist.
Once considered rare and exotic objects, black holes are now known to exist throughout the universe, with the largest and most massive found at the centers of the largest galaxies. These “ultra-massive” black holes have been shown to have masses upwards of one billion times that of our own Sun. Now, Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University and a fellow at the Radcliffe Institute for Advanced Study, has shown that even the biggest of these gravitational monsters can’t keep growing forever. Instead, they appear to curb their own growth – once they accumulate about 10 billion times the mass of the Sun.
These ultra-massive black holes, found at the centers of giant elliptical galaxies in huge galaxy clusters, are the biggest in the known universe. Even the large black hole at the center of our own Milky Way galaxy is thousands of times less massive than these behemoths. But these gigantic black holes, which accumulate mass by sucking in matter from neighboring gas, dust and stars, seem unable to grow beyond this limit regardless of where – and when – they appear in the universe. “It’s not just happening today,” said Natarajan. “They shut off at every epoch in the universe.”
The study, to appear in the Monthly Notices of the Royal Astronomical Society (MNRAS), represents the first time an upper mass limit has been derived for black holes. Natarajan used existing optical and X-ray data of these ultra-massive black holes to show that, in order for those various observations to be consistent, the black holes must essentially shut off at some point in their evolution.
One possible explanation put forth by Natarajan is that the black holes eventually reach the point when they radiate so much energy as they consume their surroundings that they end up interfering with the very gas supply that feeds them, which may interrupt nearby star formation. The new findings have implications for the future study of galaxy formation, since many of the largest galaxies in the universe appear to co-evolve along with the black holes at their centers.
“Evidence has been mounting for the key role that black holes play in the process of galaxy formation,” said Natarajan. “But it now appears that they are likely the prima donnas of this space opera.”
The authors of the paper are Priyamvada Natarajan (Yale University and the Radcliffe Institute for Advanced Study) and Ezequiel Treister (European Southern Observatory, Chile and University of Hawaii).
Provided by Yale University
Sep 11, 2008 |
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hats off to you for the path breaking research !
Are they sure the upper limit isn't an upper limit of the way we are observing the black hole?
(Kinda like saying after it goes black, we reached the upper limit of 'visibly' observing the star)
I've wondered about this as well. Does the black hole fill up and if so, once matter breaches the event horizon does the black hole explode?
(big bang?)
No, because as the black hole absorbs matter, its event horizon expands in proportion to its mass. This expansion is such that as time goes on, the average density of a black hole becomes lower, not higher. If a black hole eats enough, you eventually reach the point where the density is so low that it would float on a big enough ocean, if it had a surface that somehow prevented the ocean from just being eaten.
http://space.news...red.html
The radius of the event horizon of a (Schwartzchild) black hole is GM/c^2, with increase in mass teh event horizon also increases in size. And most importantly, inside the event horizon spatial dimensions become timelike (and vice versa, the time dimension becomes spacelike), which implies that inside the event horizon, one can not move back in space (just as outside the event horizon, in the spacetime in which we exist, we things can't progress back in time), so all the mass will eventually be pulled into the singularity, which is the centre of the black hole.
The common black hole is "black" because of giant vacuum density gradient, which is behaving like glass sphere or semitransparent mirror due the total reflection phenomena near the event horizon. The larger the black hole is, the larger is curvature of space around it. But every space-time curvature has its own energy density by Einstein field equations, and such energy density is equivalent to additional matter density of vacuum due the E=MC^2 equivalence. This dense vacuum is surrounding black hole and it's balancing its internal mass density by such way, it decreasing surface density gradient.
If the black hole become sufficiently large, then the mass density of vacuum above black hole will compensate the mass density below event horizon, so only subtle density gradient can appear here. Therefore the vacuum density gradient will not reflect the energy from inside anymore and whole the object will change into giant glowing star, emanating both energy, both matter from inside, so called the quasar. We can compare the negative capillary waves of the sink model, which are getting faster for shorter wavelength, so they can penetrate the event horizon as well. The similar conclusion results from Yilmaz and Heim theories, you can find some transparent derivation for example here: http://arxiv.org/...1110.pdf
By Aether Wave Theory most of sufficiently large galaxies inside of our Universe were created by evaporation of quasars, and the Milky Way is no exception. The black hole siting at the center of most of galaxies is supposedly a cold remnant of quasar, which has evaporated the excessive matter. This is because only black holes larger then certain mass limit can evaporate their matter by the above mechanism.
http://en.wikiped...t_effect
Perhaps the apparent upper bound we observe is related to the density of the primordial universe. In other words, there was only so much stuff to create the black hole. Once you run out of stuff it is impossible for the black hole to become larger. Thus, the density of the early universe could be directly related to the maximum size of a black hole we see today.
Did you read the article? Why re-state it? Or is this website a billboard for your hilarious theories?
It means, the merging of such black holes is possible, but it requires a substantial time. And if it occurs at the end, it's followed by releasing a substantial energy in the form of gamma ray flash - a much higher, then the current relativity based field theory assumes. By such way, AWT explains a mysterium of ultrashort gamma ray flashes, which are so intesive, so they can travel through whole universe. http://en.wikiped...stronomy
http://www.physfo...pic=8904
http://arxivblog....oles.jpg
It's all just about thinking and good knowledge of experimental results. If somebody doesn't know these results, it can consider my theories hilarious - but it's not my problem, indeed.