Chandra Dark Matter Hint?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Feb 3, 2017.

  1. paddoboy Valued Senior Member

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    Bump on a plot from Chandra X-ray observatory reveals excess of X-rays, hinting at dark matter
    February 3, 2017 by Bob Yirka report

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    A massive cluster of yellowish galaxies, seemingly caught in a red and blue spider web of eerily distorted background galaxies, makes for a spellbinding picture from the new Advanced Camera for Surveys aboard NASA's Hubble Space Telescope. To make this unprecedented image of the cosmos, Hubble peered straight through the center of one of the most massive galaxy clusters known, called Abell 1689. The gravity of the cluster's trillion stars — plus dark matter — acts as a 2-million-light-year-wide lens in space. This gravitational lens bends and magnifies the light of the galaxies located far behind it. Some of the faintest objects in the picture are probably over 13 billion light-years away (redshift value 6). Strong gravitational lensing as observed by the Hubble Space Telescope in Abell 1689 indicates the presence of dark matter. Credit: NASA, N. Benitez (JHU), T. Broadhurst (Racah Institute of Physics/The Hebrew University), H. Ford (JHU), M. Clampin (STScI),G. Hartig (STScI), G. Illingworth (UCO/Lick Observatory), the ACS Science Team and ESA
    (Phys.org)—A team of space researchers with members from Yale University, MIT and the Harvard-Smithsonian Center for Astrophysics has found a bump in X-ray readings from the Chandra-X-ray observatory that appears to be similar to bumps seen with X-rays from other telescopes. Such bumps have been theorized to represent the decay of dark matter, which could indirectly prove it exists. The team has written a paper describing their results and have posted it on the arXiv preprint server.



    Read more at: https://phys.org/news/2017-02-plot-chandra-x-ray-observatory-reveals.html#jCp
     
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  3. paddoboy Valued Senior Member

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    https://arxiv.org/pdf/1701.07932v1.pdf

    SEARCHING FOR THE 3.5 KEV LINE IN THE DEEP FIELDS WITH CHANDRA: THE 10 MS OBSERVATIONS
    27 Jan 2017


    ABSTRACT:

    In this paper we report a 3σ detection of an emission line at ∼3.5 keV in the spectrum of the Cosmic X-ray Background using a total of ∼10 Ms Chandra observations towards the COSMOS Legacy and CDFS survey fields. The line is detected with an intensity is 8.8 ± 2.9 × 10−7 ph cm−2 s −1 . Based on our knowledge of Chandra, and the reported detection of the line by other instruments, we can rule out an instrumental origin for the line. We cannot though rule out a background fluctuation, in that case, with the current data, we place a 3σ upper limit at 10−6 ph cm−2 s −1 . We discuss the interpretation of this observed line in terms of the iron line background, S XVI charge exchange, as well as arising from sterile neutrino decay. We note that our detection is consistent with previous measurements of this line toward the Galactic center, and can be modeled as the result of sterile neutrino decay from the Milky Way when the dark matter distribution is modeled with an NFW profile. In this event, we estimate a mass ms ∼7.02 keV and a mixing angle sin2 (2θ)= 0.69–2.29 ×10−10. These derived values of the neutrino mass are in agreement with independent measurements toward galaxy clusters, the Galactic center, and M31.
     
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  5. paddoboy Valued Senior Member

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    https://arxiv.org/pdf/1503.07675v2.pdf

    The non-gravitational interactions of dark matter in colliding galaxy clusters

    Collisions between galaxy clusters provide a test of the non-gravitational forces acting on dark matter. Dark matter’s lack of deceleration in the ‘bullet cluster collision’ constrained its self-interaction cross-section σDM/m < 1.25 cm2/g (68% confidence limit) for long-ranged forces. Using the Chandra and Hubble Space Telescopes we have now observed 72 collisions, including both ‘major’ and ‘minor’ mergers. Combining these measurements statistically, we detect the existence of dark mass at 7.6σ significance. The position of the dark mass has remained closely aligned within 5.8±8.2 kpc of associated stars: implying a self-interaction cross-section σDM/m < 0.47 cm2/g (95% CL) and disfavoring some proposed extensions to the standard model.
     
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  7. RajeshTrivedi Valued Senior Member

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    Ludicrous things are happening.
    On the issue of Dark matter, this Dark matter is in its terminal stage before it is dumped for some better alternative, all these are strong revival attampets.
     
  8. paddoboy Valued Senior Member

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    No science is happening, and this is the science forum.
     

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