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Space Science

Milky Way's Black Hole a Gamma Source? 100

eldavojohn writes "A paper recently accepted for publication (preprint here) proposes a sound explanation for the source of the gamma rays that permeate our galaxy. The Milky Way's central object Sagittarius A*, widely believed to be a supermassive black hole, is now suspected to be the source. To test this theory, two scientists created a computer model to track the protons, flung outward with energies up to 100 TeV by the intense magnetic fields near the event horizon, as they make a random walk through the plasma environment. It can take thousands of years for them to travel 10 light-years from the black hole, where they collide with lower-energy protons to form pions. These decay into gamma radiation emanating from a torus-shaped region around the central object."
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Milky Way's Black Hole a Gamma Source?

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  • Re:huh? (Score:5, Informative)

    by spun ( 1352 ) <loverevolutionar ... m ['oo.' in gap]> on Tuesday March 06, 2007 @05:10PM (#18254868) Journal
    You're thinking of microwave radiation.
  • by btgreat ( 895041 ) on Tuesday March 06, 2007 @06:02PM (#18255490)
    The article was talking about protons, not photons. I'm not exactly sure whether or not the motion is random, but it certainly shouldnt have any effect on whether the PHOTONS of the star are visible or not..
  • Water Bears (Score:3, Informative)

    by Neutrino Linguino ( 1072502 ) on Tuesday March 06, 2007 @06:18PM (#18255634) Homepage
    Tardigrades [aka Water Bears], which live everywhere on this planet Earth, can...
    1) resist storage in liquid nitrogen
    2) survive in contact with mineral acids, organic solvents, and boiling water
    3) survive in a a vacuum and under high pressure
    4) withstand ionizing radiation of over 600,000 roentgens (500 roentgens would be fatal to a human)
  • by PhrostyMcByte ( 589271 ) <> on Tuesday March 06, 2007 @06:43PM (#18255940) Homepage

    Would someone please explain why parent is modded funny?

    A* [] is a path finding algorithm. It is used in many games, such as Starcraft.

  • Re:Do we know? (Score:4, Informative)

    by Fujisawa Sensei ( 207127 ) on Tuesday March 06, 2007 @07:14PM (#18256332) Journal

    We know a lot more than you give us credit for, perhaps you need to read a little deeper, try Relativity by Albert Einstein. AE just made up stuff because observations didn't fit Newtons proven model. So he just made up some equations to match the observations. But alas his made up equations didn't correctly model acceleration or gravity, so he made up GR.

    GR is a very accurate theory, and there is experimental evidence of it. The two most famous are the perihelion precession of Mercury, and stars visible near the eclipsed sun. Of course being semi-interested in Cosmology/Astrophysics you would already know that.

    Stuff like Dark Matter that just doesn't get made up, it falls out naturally when equations which are shown to work in one situation are shown to fail in another. DM vs GR for example. There's a lot of guess work as to what DM is, but that's where life gets interesting, we don't know what it is. We know 'something' is there, we just don't know what the something is. DM isn't a convenience item, its a wart, because without the wart GR which is shown to work in other cases could be used to correctly model galactic motion.

  • by Anonymous Coward on Tuesday March 06, 2007 @09:16PM (#18257546)
    No, they still don't emit anything (except Hawking radiation, and that's kind of complicated). These gamma rays are from protons getting close to the event horizon, but then getting shot away at incredibly high energies due to interactions with the massive magnetic fields in the area. They then smack into other particles, releasing a shower of sub-particles and gamme rays.

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