Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
Space Science

'Seeds' of Supermassive Black Holes Discovered 37

Posted by Soulskill
from the good-crop-next-year dept.
astroengine writes "The very existence of intermediate black holes (IBMHs) is in dispute, but a group of astronomers of Keio University, Japan, have found the potential locations of three IMBH candidates inside previously unknown star clusters near the center of the Milky Way. Using the 10-meter Atacama Submillimeter Telescope Experiment in the Atacama Desert, Chile, and the 45-meter Nobeyama Radio Observatory in Japan, they hunted for the emissions from molecular gases associated with supernovae in star clusters — what they discovered could help evolve our view on how supermassive black holes form."
This discussion has been archived. No new comments can be posted.

'Seeds' of Supermassive Black Holes Discovered

Comments Filter:
  • Well? (Score:5, Funny)

    by santax (1541065) on Wednesday July 25, 2012 @04:00PM (#40769337)
    Was it a true random seed?
  • ... the seedless variety.

  • Really? (Score:1, Interesting)

    by jacerie (1071646)
    "The very existence of intermediate black holes is in dispute..." By definition, An Intermediate-mass black hole is a black hole whose mass is significantly more than stellar black holes (ten times to several tens of times the mass of the Sun) yet far less than supermassive black holes (one million to many million times the mass of the Sun). A healthy dose of common sense and a basic understanding of gravity makes it pretty clear that any stellar black hole has the potential to become an IMBH. I appreciat
    • Re:Really? (Score:5, Interesting)

      by History's Coming To (1059484) on Wednesday July 25, 2012 @07:04PM (#40771519) Journal
      Incorrect, you're letting intuition get in the way. Space is big. Really big. And even if you collapse our entire solar system into a black hole then it would still have exactly the same mass as it always did, so from a distance nothing changes much. Yeah, there's a black hole where there used to be a star and some assorted debris, but it just keeps on cruising through space like it always did.

      The chances of it reaching enough other bits of matter to gain a million times its own mass aren't very good, and the event horizon of a solar mass black hole is only 6km across, if it even hit another solar system it would have to be a slow pass or direct hit on the star, anything else would just perturb a few orbits and pass straight through.

      Black holes also evaporate with time (due to Hawking radiation), the smaller they are the faster they evaporate. Our solar mass black hole will be nothing but an expanding cloud of weak black body photons unless a very unlikely series of events occurs.

      Of course, they could merge with a nearby supermassive if they get caught up in it (e.g. Sag A*), but at no point in that whole story is there an Intermediate Mass Black Hole, the question stands.
      • by PPH (736903)

        But this dearth of IMBHs could help to explain some subtle interactions between gravity, dark matter and dark energy.

        The classical thinking about stellar black holes having the same gravitational attraction as their parent star did might be wrong. Its possible that, once a stellar black hole has formed, local effects accelerate its scouring of nearby mass until it becomes a massive BH. So IMBHs are a transition state between small and large and don't spend much time (galactically speaking) as such. So thei

      • by aliquis (678370)

        Of course, they could merge with a nearby supermassive if they get caught up in it (e.g. Sag A*), but at no point in that whole story is there an Intermediate Mass Black Hole, the question stands.

        http://en.wikipedia.org/wiki/Sagittarius_A* [wikipedia.org]

        Sagittarius A* (pronounced "Sagittarius A-star", standard abbreviation Sgr A*) is a bright and very compact astronomical radio source at the center of the Milky Way Galaxy

        Much be of the intellectual kind!

        "Imagine it played Britney Spears 27,000 years ago!"

      • by jacerie (1071646)
        I can't argue with anything you've pointed out and agree that the odds of a black hole with the mass of our sun ever reaching IMBH status,or even existing, is slim to none. I think the main issue I have is the broad definition of an IMBH itself. It is widely accepted that in order for a star to achieve a black hole state it must have a mass greater that three times the mass of Sol after any main sequence loss. Right there you're more than 25% to the minimum mass for an IMBH. If the IMBH tag is simply a me
      • Black holes also evaporate with time (due to Hawking radiation), the smaller they are the faster they evaporate. Our solar mass black hole will be nothing but an expanding cloud of weak black body photons unless a very unlikely series of events occurs.

        Hawking radiation is irrelevant -- it takes 10^61 times the age of the Universe for a 30 solar mass black hole to evaporate, and the time scales with M^3. http://casa.colorado.edu/~ajsh/hawk.html [colorado.edu]

      • No argument with your points, they're all good. However, it's not just intution, it's an "educated guess" which is the same as what you are doing. TFA suggests star clusters as a possible mechanisim for forming IMBH's which changes some of the assumptions you're using, particularly about the density of gavitationally bound stars in a given volume of space.

        For an old fart like me it doesn't seem that long ago when scientists were insisting black holes of ANY size were no more than a "mathematical curiosit
        • Sgr A* (thanks for the correction above!) was the first thing that convinced me that black holes probably exist. The orbits of the stars in the region suggest something that is either dense enough to be a black hole or something equally exotic and as-yet unknown (e.g. not a boring old neutron star). And I'm only a 30-something year old fart ;)

          My main point was that while there is a good mechanism for solar mass black holes (or a couple of magnitudes thereof) through standard stellar evolution, and ther
          • so whether they exist and what the production mechanism is is still up for grabs

            Agree. Also agree that orbiting stars are convincing evidence, whereas x-ray point sources are just likely targets. I also think the origin of SMBH is not well understood, but until someone comes up with a more convincing alternative I will stick with ammalgamation as the most likely origin. Perhaps the demographics of black holes changes as the universe evolves, but finding likely targets may be difficult since the x-rays come from the accretion disk, so their strength is not a good indicator of mass. If w

    • Unless you're in an unusually dense star cluster, sooner or later, you're going to run out of mass.

    • Re:Really? (Score:5, Insightful)

      by dido (9125) <dido&imperium,ph> on Wednesday July 25, 2012 @07:57PM (#40771863)

      The reason astronomers seem to dispute the potential for the existence of these intermediate mass black holes is that no one has yet shown convincing evidence that they exist, nor do they have any convincing theories on how they could be formed. No star is massive enough to have collapsed into the alleged IMBH GCIRS 13E [wikipedia.org], which is supposed to be 1300 solar masses. For several smaller stellar black holes to coalesce into something like GCIRS 13E, that seems far less likely. Away from galactic cores where everything is very close together, stellar collisions are extremely rare. Collisions between black holes considerably more so. Contrary to popular perception black holes are not the all-sucking vacuum cleaners of the universe. Their gravity is not so different from the gravity of any other object, except beyond the event horizon. A stellar black hole five times the mass of our sun would have no more ability to attract things to itself with gravity than a star of five solar masses. So while black holes could collide, in interstellar space they don't do so very frequently, as much of interstellar space is empty, and as such, a few hundred of them coming together to form an IMBH of a thousand or so solar masses is extremely unlikely to say the least. In galactic cores on the other hand things are so close together that accretion of stuff into a black hole there would tend to continue until there's a supermassive black hole, not stopping at the thousand or so solar masses that IMBHs are hypothesized to be. The only other explanation for the formation of IMBHs is that they are primordial black holes created a fraction of a second into the birth of the universe, but this is even more shaky to say the least. Regardless of the explanation, the fact is observational evidence for IMBHs is disputed, and is nowhere near as conclusive as the evidence for stellar and supermassive black holes is. Granted, they could exist in principle, but if observational evidence is flimsy and the conditions necessary for creating one so unlikely then one might be justified in doubting their existence.

      • by jafiwam (310805)

        You are misinterpreting what they mean.

        CANT exist, and DONT exist are very different concepts.

        You are reading one, and hearing another.

        I suggest a little philosophy and linquistics 101 to clear this up, it's a severe handicap when dealing with math, physics, and cosmology.

  • incorrect (Score:4, Interesting)

    by slashmydots (2189826) on Wednesday July 25, 2012 @08:51PM (#40772283)
    Actually, every black hole is the same size and they're quite small. I believe what they meant was mass.
    • Re:incorrect (Score:5, Informative)

      by Ambitwistor (1041236) on Wednesday July 25, 2012 @09:40PM (#40772595)

      The size of a black hole is proportional to its mass: its diameter is 6 kilometers per solar mass. You're probably confusing the size of the singularity (zero, or close to it) with the size of the black hole (the event horizon surrounding the singularity).

No one gets sick on Wednesdays.

Working...