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New Galaxy Discovered That's Light on Dark Matter

posted by takyon on Monday April 01 2019, @09:35PM   Printer-friendly
from the gaaarlaktus dept.

An Anonymous Coward writes:

From New Atlas:

Some of the strongest evidence for dark matter to date has been discovered – and ironically, that's thanks to its absence. In a pair of studies published this week, astronomers have shed new light on dark matter through close observation of a galaxy previously found to have very little of the stuff, while the same team found a new example of a similar oddball galaxy.

It's generally believed that galaxies are held together through the gravitational influence of clumps of dark matter, so to find a galaxy with little to no dark matter was a surprise. And while it might sound like a strike against the theory, it actually ends up supporting it.

A Second Galaxy Missing Dark Matter in the NGC 1052 Group (DOI: 10.3847/2041-8213/ab0d92) (DX)

Still Missing Dark Matter: KCWI High-resolution Stellar Kinematics of NGC1052-DF2 (DOI: 10.3847/2041-8213/ab0e8c) (DX)

Original Submission

 
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  • (Score: 1) by khallow on Wednesday April 03 2019, @04:16AM (5 children)

    by khallow (3766) Subscriber Badge on Wednesday April 03 2019, @04:16AM (#823963) Journal

    And yet you have big problem with QI, even though it is a better, more scientific model.

    The catch is that MOND at least explains most galaxies with "no" dark matter effects as being embedded in a stronger gravitational field. QI seems to predict that dark matter effects should be stronger because of the weak internal gravitational field of the galaxy rather than the opposite which is actually observed.

  • (Score: 2) by Gaaark on Wednesday April 03 2019, @10:21AM (4 children)

    by Gaaark (41) Subscriber Badge on Wednesday April 03 2019, @10:21AM (#824024) Journal

    Uhhhh,...QI seems to predict there IS NO dark matter.

    --
    --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---

    • (Score: 1) by khallow on Wednesday April 03 2019, @12:51PM (3 children)

      by khallow (3766) Subscriber Badge on Wednesday April 03 2019, @12:51PM (#824052) Journal
      The effect not the matter. The problem is that QI predicts stronger dark matter effects for galaxies that have low density yet the two mentioned satellite galaxies have little apparent dark matter effects. The traditional explanation is that nearby NGC 1052 stole the dark matter. The MOND explanation is that the satellite galaxies reside in the stronger gravitational field of NGC 1052 and hence are in the Newtonian regime of gravitational acceleration.

      • (Score: 2) by Gaaark on Wednesday April 03 2019, @10:45PM (2 children)

        by Gaaark (41) Subscriber Badge on Wednesday April 03 2019, @10:45PM (#824275) Journal

        Okay, I guess I don't understand where you are going.
        QI only deals with motion and speed: galaxies don't fly apart due to inertia.

        --
        --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---

        • (Score: 1) by khallow on Wednesday April 03 2019, @11:12PM (1 child)

          by khallow (3766) Subscriber Badge on Wednesday April 03 2019, @11:12PM (#824286) Journal

          QI only deals with motion and speed: galaxies don't fly apart due to inertia.

          The problem here was motion and speed of rare sorts of galaxies that the other two theories have figured out how to shoehorn explanations for. The QI explanation is lacking since the galaxies in question are low density satellite galaxies, most of their mass got robbed by NGC 1052 in some long ago collisions. So they're precisely the sort of low local gravity objects that QI should be describing. Unless QI has the MOND issue where external gravitation fields (here from NGC 1052) cause the physics to somehow change.

          • (Score: 2) by Gaaark on Thursday April 04 2019, @01:37AM

            by Gaaark (41) Subscriber Badge on Thursday April 04 2019, @01:37AM (#824324) Journal

            run the numbers against his formula.

            I'm betting you get the numbers you're looking for.

            --
            --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---