Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Too Much Dark Matter In CEG Mrk 1216

  1. Feb 14, 2019 at 12:11 AM #1


    User Avatar
    Gold Member

    New observations of Compact Elliptical Galaxy Mrk 1216 show a very high apparently dark matter fraction based upon the intragalaxy dynamics of stars in the galaxy, relative to the baryonic mass of the galaxy inferred from typical mass to light ratios for galaxies of that type.

    The inferred amount of dark matter in the galaxy is 3-6 sigma above the ΛCDM model based upon seemingly reasonable assumptions about the galaxy.

    Similarly, so much of the galaxy has a gravitational field strength in excess of the MOND constant, a0 that MOND also predicts that there should b few observable dark matter phenomena there.

    So, the mystery is why there is some much apparent dark matter there where it doesn't belong.

    The paper is:
    I haven't been able to discern what changes were made in version two of the paper, released yesterday, but whatever changes were made, they don't seem to disturb the main thrust of the scientific conclusions of the original version of the article.

    If true, this would be the most paradigm upsetting discovery in many years or even more than one decade. But, there are multiple ways that this could plausibly arise from various kinds of systemic error in the measurements done.
  2. jcsd
  3. Feb 14, 2019 at 11:11 AM #2


    User Avatar
    Science Advisor

    I may be wrong, but I think these analyses assume that the galaxy is in some sort of dynamic equilibrium. If that is not the case because of a recent "event", such as a merger, SMBH coalescence or something else, then won't the analyses based on stellar dynamics come to the wrong conclusions?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?