mollwollfumble said:
CrazyNeutrino said:
Scientists Map the Dark Matter Around Millions of Galaxies
This week, scientists with the Dark Energy Survey (DES) collaboration released the first in a series of detailed maps charting the distribution of dark matter inferred from its gravitational effects. The new maps confirm current theories that suggest galaxies will form where large concentrations of dark matter exist. The new data show large filaments of dark matter where visible galaxies and galaxy clusters lie and cosmic voids where very few galaxies reside.
more…
About 15 degrees by 15 degrees. Good.
> The new data show large filaments of dark matter where visible galaxies and galaxy clusters lie and cosmic voids where very few galaxies reside. Our analysis so far is in line with what the current picture of the universe predicts.
Good, but I hope that they’re performing the essential task of lining up the dark matter calculated from the Dark Matter Survey from the DEC with that predicted from the Planck map of the cosmic microwave background. There ought to be a strong correlation, and the strength of that correlation ought to tell us a great deal about the early universe.
Oops. It took me a while to realise that this is totally unexpected. The survey is the Dark Energy Survey, not the Dark Matter Survey. The camera DECam is designed to look for distant supernovae. So this survey of dark matter is outside the scope of the publicity brochure. My expectation is that the Dark Energy Survey will give a null result, in the sense that dark energy of anticipated forms (cosmological constant, quintessence, or phantom energy) should give results that are isotropic – no statistically significant variation across the whole of the survey region.
… unless,
unless the distribution of galaxy clusters and superclusters is variable across the survey region, which it is. Hmm, then comparing the distribution of dark energy to dark mass gives a difference in distribution between visible matter (at known distances, from the dark energy survey) and distribution of dark matter (at unknown distances). This could get exciting.