Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Space Science

Black Hole Found That Takes Up 14% of Its Galaxy's Mass 65

Posted by Soulskill from the fat-guy-little-coat dept.
An anonymous reader sent word that astronomers have discovered an absolutely enormous black hole residing in a galaxy that seems too small for it. In a new study (PDF), researchers looked at galaxy NGC 1277 and found that its central black hole weighed in at roughly 17 billion solar masses. Quoting Phil Plait: "The problem is, that’s far more massive than the central bulge of NGC 1277 would suggest the black hole should be. It’s well over half the total mass of the bulge! In fact, the entire mass of the galaxy is about 120 billion solar masses, which means the black hole at its heart is 14 percent of the total galaxy’s mass; compare that to the Milky Way’s black hole mass of 0.01 percent and you’ll see why astronomers were shocked."
This discussion has been archived. No new comments can be posted.

Black Hole Found That Takes Up 14% of Its Galaxy's Mass More

Black Hole Found That Takes Up 14% of Its Galaxy's Mass

Comments Filter:

  • In fairness, it used to be a much bigger galaxy. Just wait for the x-ray/gamma ray belch which will come just before it decides to take a nap.

  • Missing from the summary (Score:5, Interesting)

    by mcgrew ( 92797 ) * on Friday November 30, 2012 @03:43PM (#42147053) Homepage Journal

    It's the largest black hole they've yet found, if the article I saw yesterday is correct.

  • It might be easier to study since it's so big (Score:3, Interesting)

    by voislav98 ( 1004117 ) on Friday November 30, 2012 @03:54PM (#42147221)
    I wonder if, with a black hole as large and relatively less shielded, you can look for some evidence of relativistic effects around it.

  • That's not a galaxy... (Score:5, Interesting)

    by idontgno ( 624372 ) on Friday November 30, 2012 @03:54PM (#42147229) Journal
    that's an accretion disc [wikipedia.org].

  • This is what happens (Score:3)

    by stox ( 131684 ) on Friday November 30, 2012 @03:55PM (#42147243) Homepage

    when you let the Walton Family take over a galaxy.

  • maybe most of the rest of the mass was stripped by some sort of galactic near-collision.

  • Visualization of how large NGC 1277 (Score:5, Interesting)

    by rminsk ( 831757 ) on Friday November 30, 2012 @03:58PM (#42147275)
    From redditor xSmoothx post titled "Putting into perspective just how big the black hole of NGC 1277 truly is" [imgur.com]

    • Re: Visualization of how large NGC 1277 (Score:4, Interesting)

      by Baloroth ( 2370816 ) on Friday November 30, 2012 @04:18PM (#42147581)

      And, interestingly enough, given the mass and size of the hole, air at sea level is about 19 times more dense than the black hole is. Black holes are just strange.

      • Comment removed based on user account deletion

      • Re: Visualization of how large NGC 1277 (Score:4, Informative)

        by Chris Burke ( 6130 ) on Friday November 30, 2012 @05:20PM (#42148541) Homepage

        Well yes if you use the size of the event horizon and the mass of the black hole to calculate density then you get a low density.

        But the mass is not distributed over that volume. inside the black hole the mass is actually contained in an infintesimal point, and the density is infinite. At least according to the math; it's impossible to look inside the event horizon to find out if that's really the case.

        At the very least it's clear that a black hole must have density significantly higher than that of a neutron star. Saying it's less dense than the air is misleading in that respect.

        • But the mass is not distributed over that volume. inside the black hole the mass is actually contained in an infintesimal point, and the density is infinite. At least according to the math;

          Ah yes, but it also can't be, since time travels slower and slower the deeper you go, it would take infinite time for matter to actually reach that point. The actual matter distribution depends on a lot of things, mostly how it was formed. Presumably, there is at least a central region with density greater than a neutron star, but if the majority of the matter in the star was added later, or was otherwise distributed throughout the whole region of the black hole during or after it's formation, that matter w

        • Re: (Score:2)

          by ceoyoyo ( 59147 )

          The math is overly simplified. There is no realistic way the mass could be concentrated at the centre. It takes an infinitely long time for infalling mass to just reach the event horizon.

        • Re: Visualization of how large NGC 1277 (Score:5, Interesting)

          by turbidostato ( 878842 ) on Friday November 30, 2012 @06:39PM (#42149763)

          "But the mass is not distributed over that volume. inside the black hole the mass is actually contained in an infintesimal point"

          Ahh! the old problem... equations versus reality!

          All that the Einstenian equations tell us is that they don't know how to manage black holes beyond the event horizon (and that they are wrong about them because of that).

          Given that the event horizon neatly divides the universe in two, it is perfectly reasonable to say that the black hole density (from the outer univese perspetive) averages its overall percieved mass by its volume.

          At the very least it's clear that a black hole must have "density significantly higher than that of a neutron star."

          Because?

          All you can say is that *if* (a big if) black holes behave more or less like all the physics we know about, there must be something within the black hole with densities above those we can find on a neutron star because by all we "common sense" know, black holes are like neutron stars, only more so.

          "Saying it's less dense than the air is misleading in that respect."

          What's misleading about saying density is defined as mass against volume?

          • Ahh! the old problem... equations versus reality!

            All that the Einstenian equations tell us is that they don't know how to manage black holes beyond the event horizon (and that they are wrong about them because of that).

            Ahh, the old problem of equations versus your imagination of what reality might be. ;)

            Einstein's equations work just fine inside the event horizon. It's the actual singularity itself which raises some eyebrows. And even then, we don't actually know that such a thing isn't possible in reality. But you are uncomfortable with the idea, therefore they're wrong. Got it.

            At the very least it's clear that a black hole must have "density significantly higher than that of a neutron star."

            Because?

            Because it's required by those pesky equations.

            All you can say is that *if* (a big if) black holes behave more or less like all the physics we know about

            Everything said about just about anything can be presumed to have an "as long as our understan

  • since just last night I watched a video on YouTube where Neil DeGrasse Tyson asserted that we've found all the matter out there, and that the missing stuff is all Dark Matter.

    (I think that this [youtube.com] was it.)

    • Not that odd... (Score:5, Informative)

      by Gunnut1124 ( 961311 ) <rowdy DOT vinson AT gmail DOT com> on Friday November 30, 2012 @04:44PM (#42147919)
      This is just an example of a MaCHO [wikipedia.org]. We've theorized about them for a while. They are a strong candidate for a bulk of the dark matter we've detected. The other candidates are WIMPs [wikipedia.org].

      • This is just an example of a MaCHO [wikipedia.org]. We've theorized about them for a while. They are a strong candidate for a bulk of the dark matter we've detected. The other candidates are WIMPs [wikipedia.org].

        Uh, no. MaCHOs were supposed to be Jupiter-size to brown dwarf-size lumps of mass, careening through galaxies without being associated with stars or other luminous matter. A black hole *can* count as a MaCHO *if* it has no accretion disk, but we think most black holes have accretion disks and therefore emit X-rays (and thus don't count as dark matter). This black hole is firmly in the not-a-MaCHO category; for that matter, what we today know about Big Bang baryogenesis pretty strongly rules out MaCHOs be

    • Re: (Score:2)

      by Anonymous Coward

      There are actually two kinds of missing matter at this point. Evidence based on things from the Big Bang like the cosmic microwave background and relative abundance of light elements gives us an idea what portion of the mass in the universe would be made up from baryonic matter (things like protons and neutrons, so pretty much anything made of atoms), and then there is a large portion of mass that needs to be made up of something else, that is what gets called dark matter. Of the portion we think that is

    • If you think that he intended to say that we have literally seen every object in the universe made of normal matter, then you didn't think enough.

  • Somebody sure stashed a lot of weed in that Black Hole. I'm hungry man, let's eat a couple stars.

  • Obvious Explanation (Score:1)

    by Anonymous Coward

    Someone's been playing too much Katamari.

  • We have a black hole in DC that accounts for 20 something % of our economic mass...

  • still waiting for 1 trillion+ solar masses... (Score:4, Interesting)

    by PJ6 ( 1151747 ) on Friday November 30, 2012 @08:51PM (#42151109)
    I read (I think it was in 'death by black hole') that the more massive the black hole, the less gravity you experience at the event horizon. For a 1 trillion mass black hole, supposedly it would only have 10g at its event horizon. For still greater masses, you could have 1g, something reasonable for both a human and a spaceship to deal with... in theory, you could hover a ship with a person in it at the very boundary of such an event horizon... how sharp would this boundary be? I'd lower a string to see where and how it gets clipped.
  • And yet we calculated dark matter into existence with 100% accuracy, I'm sure.
  • Do physicists know for sure that there is a singularity at the heart of a black hole? Couldn't it just be something extremely (but not infinitely) dense?

Slashdot Top Deals

In the long run, every program becomes rococco, and then rubble. -- Alan Perlis

Close