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Possible Dark Matter Signs At the Core 234

Posted by kdawson
from the quantum-two-hyperdrive dept.
Scientific American has a piece on speculation that dark matter may be behind diffuse radiation in the galactic center. Beginning in 2003, researchers led by Douglas Finkbeiner noticed a curious excess of microwave radiation in the WMAP data, after all known sources of such radiation were accounted for. Data from NASA's Fermi Gamma-Ray Space Telescope resulted in a similar anomaly in gamma rays. "A paper posted to the physics preprint Web site arXiv.org on October 26 and submitted to the Astrophysical Journal points to a possible signature of dark matter in the Milky Way, although the study's authors are careful to keep their observations empirical and table such speculation... In the new paper [the researchers] describe the Fermi gamma-ray haze and make the claim that it confirms the synchrotron origin of the WMAP microwave haze. And as with the microwave haze, the authors argue that the electrons responsible for the gamma-ray haze appear to originate from an unknown astrophysical process. ... 'We are absolutely in the process of exploring the Fermi haze in the context of dark matter physics,' [one of them] says."
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Possible Dark Matter Signs At the Core

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  • by shentino (1139071) on Tuesday November 03, 2009 @08:27PM (#29971490)

    Of course it's dark matter in the middle

    • by selven (1556643) on Tuesday November 03, 2009 @08:33PM (#29971584)

      Black hole and dark matter have very precise meanings in physics. In fact, black holes aren't strictly black due to Hawking radiation and dark matter is transparent, not dark.

      • by wizardforce (1005805) on Tuesday November 03, 2009 @08:56PM (#29971826) Journal

        Close. Black holes emit hawking radiation in so far as physics is concerned however, the more massive a black hole is the less bright it is. A black hole with twice the mass of another black hoel will be 1/8th as bright as the smaller black hole. For blackholes largers than the sun, the hawking radiation is so miniscule that the lifetime of the black hole is on the order of 10^60+ years before it "evaporates." Dark matter O.T.O.H. is merely undetectable with current instrumentation outside of indirect gravitational effects.

        • Re: (Score:3, Insightful)

          by Locke2005 (849178)
          If dark matter is "undetectable", then why are they attributing microwave radiation to dark matter, instead of, say, the energy given off by normal matter falling into the black hole at the center of the galaxy? (What happens when dark matter falls into a black hole, anyway?)
          • Re: (Score:3, Insightful)

            by wizardforce (1005805)

            It looks like they're claiming that the radiation from these electrons indicates that a process of higher energy than a supernova caused the phenomena. I presume that the process they're talking about is the decay of WIMPs and other dark matter candidates. The dark matter its self hasn't been directly detected unless you're counting this paper as an example of the contrary. The problem is that this is a very new paper in arxiv and as such requires much more peer review before we can say with reasonable c

          • by khallow (566160)

            If dark matter is "undetectable",

            No. Dark matter is undetectable with current instrumentation. And actually they've already detected and imaged it with gravity lensing, so that's not entirely accurate either.

            • by hitmark (640295)

              i guess one can state that they cant be directly observed on the EM spectrum, only indirectly by whatever effect they have on other nearby EM sources.

        • For blackholes largers than the sun,

          Larger in what way - radius or mass? Don't stars need to be at least three solar masses before they can implode into a black hole? And if so, are you describing a special case?

      • by CopaceticOpus (965603) on Tuesday November 03, 2009 @10:18PM (#29972548)

        Black hole and dark matter have very precise meanings in physics.

        Just like woosh has a very precise meaning on Slashdot.

        • by selven (1556643)

          Well, to continue the Slashdot tradition:

          Just like whoosh has a very precise meaning on Slashdot.

          Fixed.

      • by Urkki (668283)

        Black hole and dark matter have very precise meanings in physics.

        Yeah, the very precise definition of dark matter being "the invisible shit with gravitational mass, about which we don't know what the fuck it is".

    • by causality (777677) on Tuesday November 03, 2009 @08:39PM (#29971632)

      Of course it's dark matter in the middle

      Dark matter is sort of like violence. If it doesn't work, just use more of it.

      • Re: (Score:2, Funny)

        by Zarf (5735)

        You have a profound understanding of Physics. That's exactly what physicists do.

        Of course it's dark matter in the middle

        Dark matter is sort of like violence. If it doesn't work, just use more of it.

      • by xbytor (215790)
        XML is sort of like violence. If it doesn't work, just use more of it.

        FTFY.
    • It's not all doom and gloom. I've heard there is in-flight spaghetti and fiction.
    • Re: (Score:3, Insightful)

      by blueg3 (192743)

      No, "dark matter" and "dark energy" are just discrepancies in two particular aspects of astrophysics. Empirical observations suggest that there's more matter out there than we can see. However, because they sound vague and they're active areas of research (that is, they're mentioned often and it's clear we don't know what they are), people who have no real understanding of physics jump to the conclusion that it's some general hand-waving. Perhaps this makes them reinforces their belief that they're so much

  • by Gizzmonic (412910) on Tuesday November 03, 2009 @08:56PM (#29971816) Homepage Journal

    CAPTAIN KIRK: Spock, come in here, can you make sense of these readings?

    SPOCK: Captain, it appears that dark matter may be behind diffuse radiation in the galactic center.

    CAPTAIN KIRK: It's the most magnificent thing I've ever seen!

    SPOCK: It is...fascinating.

    CAPTAIN KIRK: But why would diffuse radiation need a starship?

    DR. MCCOY: Come on over here, boys! This galactic dick ain't gonna suck itself!

    Thanks for reading and supporting fan fiction.

  • Purple haze all in my eyes Don't know if it's day or night You've got me blowin, blowin my mind Is it tomorrow or just the end of time? - Jimi Hendrix
  • Why do we keep invoking "dark matter" to explain that which is adequately explained by the massive black hole at the center of this and almost every other galaxy?
    • Re: (Score:3, Informative)

      Why do we keep invoking "dark matter" to explain that which is adequately explained by the massive black hole at the center of this and almost every other galaxy?

      Because the massive black holes don't adequately explain things.

      Rotation speeds of stars about the center of the galaxy don't behave as they should in the case where the massive black hole is the only thing acting on them other than nearby bits of galaxy.

      • by joh (27088)

        There's still the possibility that there's something wrong with our understanding of mass and gravity in a subtle way. The flyby anomaly [wikipedia.org] is not explained either yet and it may well be that a similar thing is going on in the center of the galaxy on a much larger scale.

        But I certainly agree that any test of any theory is welcome here. There's something fishy with our understanding of the universe and I can't stand this ;-)

    • Because it isn't.

    • Re: (Score:2, Insightful)

      by hldn (1085833)

      because you're an astrophysics noob and don't realize that blackholes do not explain it at all.

  • by Anonymous Coward

    ...like I like my cosmological hypotheses. Dark, with a nice distribution of heat.

    • by armyofone (594988)

      While I prefer my coffee like I like my women... cold, and bitter.

      • by PachmanP (881352)

        While I prefer my coffee like I like my women... cold, and bitter.

        I prefer my coffee like I like my women...with my dick in it!

  • by BitZtream (692029) on Tuesday November 03, 2009 @10:15PM (#29972520)

    Magic?

  • Lots of Dark Matter at the galaxy's core? So they just found the path to the Niblonians' home planet?

Fools ignore complexity. Pragmatists suffer it. Some can avoid it. Geniuses remove it. -- Perlis's Programming Proverb #58, SIGPLAN Notices, Sept. 1982

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