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Black Holes Can Only Get So Big

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)

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)

Black holes are thought to exist throughout the universe, with the largest and most massive found at the centers of the largest galaxies. These supermassive black holes have been shown to have masses upwards of one billion times that of our own Sun. But an astronomer studying black holes says there’s an upper limit to how big a black hole can get. Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University 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.”

Natarajan’s study is 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.

Artist\'s conception of a black hole.  Credit:  U of Tel Aviv

Artist's conception of a black hole. Credit: U of Tel Aviv

One possible explanation, says 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.”

Source: PhysOrg


Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

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  • PSYCHONAUT November 28, 2008, 10:30 PM

    Black holes continue to enlarge until the “big crunch” which occurs after all matter in a space-time continuum is completely eradicated by blackholes through something i will call time-void phasing. During some of my early ego death experiments into the true nature of reality, i discovered much insight into this area cosmology. A fair analagy is that black holes are to physical universes as plant life is to earthlings (plants take animal CO2 waste and give lifeforms oxygen fuel) Black holes absorb matter and then “phase” as it into the next universe as energy for the next big bang.

    Also bare in mind that matter is energy slowed down to a certian speed or frequency with photons being the highest frequency for physical matter. Time slows down for matter the nearer it approaches the center of the black hole which is a time void (time axis is warped so badly it no longer is connected to any of the 3 spacial axes). Eventually, the devoured matter is naturally changed by the gravity into pure energy (matter vibrating at an infinite speed/frequency) due to the particle breakdown with the law of conservation allowing it to pass out of our universe using the time void into another one (sometimes back into our own). the energy that doesnt get radiated back into ours as hawkings radiation becomes the fuel for:

    1 the next universe’s big bang that occurs after our own crunches
    2 a previous one that crunched before our own
    3 and even recycled for the big bang responsible for our own universes creation.

    Essentially this process allows an infinite number of physical universes to exist using the same finite amount of energy (pure energy mind you with infinite speed & frequency) that was created from the opposal creation of conciousness and nothingness which is what happened before the first big bang and way too complicated & abstract to explain with langauge in a timely manner on a forum. I’d imagine i’d have to use vague references to things like thought cancellation from redundant opposal awareness and chain reacting shifts in the will. It’s only completely understood while experiencing ego death (or actually dying!) since your conciousness is then existing in that same non-physical reality that the time-voids in black holes contain* but without the maecrocosmic shell limit of time’s linear sequencing effect that prevents
    At least not in this universe anyway…

  • c henry January 6, 2009, 11:02 PM

    this coincides with my theory that galaxies are nothing more than a seed pod for future universal creation bangs…. i’m glad 2 see that im not the only person who sees this correllation… keep up the good work… chris