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A comment on New class of galaxy has been discovered, made almost entirely of dark matter. Parent comment

Re:New class of galaxy has been discovered, made almost enti... by semi-extrinsic on Friday August 26, 2016 @02:22PM (#12368201)
Regarding the "no massive dark bodies" result: does this also cover dark dust? Or is that otherwise ruled out (perhaps by optical density)?
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Re:New class of galaxy has been discovered, made almost enti... by tomr_stargazer on Friday August 26, 2016 @02:36PM (#12368296)
Additional dust inside a given galaxy would both absorb optical light and emit infrared light (depending on its temperature, which is set by the Galaxy's ambient starlight among other factors); both effects are readily detectable.
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Re:New class of galaxy has been discovered, made almost enti... by okket on Friday August 26, 2016 @02:35PM (#12368279)
If you have four times of visible matter as "dark dust", this dust would clump together, creating stars, becoming visible matter again.
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Re:New class of galaxy has been discovered, made almost enti... by maverick_iceman on Friday August 26, 2016 @02:32PM (#12368264)
Baryonic dust is ruled out by BBN.
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