HUBBLE OBSERVATIONS SUGGEST A MISSING INGREDIENT IN DARK MATTER THEORIES

bsharma writes: A dark matter measurement technique involves measuring how dark matter's gravity in a massive galaxy cluster magnifies and warps light from a distant background galaxy. This phenomenon, called gravitational lensing, produces smeared images of remote galaxies and occasionally multiple copies of a single image.

A recent study of 11 hefty galaxy clusters found that some small-scale clumps of dark matter are so concentrated that the lensing effects they produce are 10 times stronger than expected. These concentrations are associated with individual cluster galaxies.

Researchers using the Hubble Space Telescope and the European Southern Observatory's Very Large Telescope in Chile discovered with unprecedented detail smaller-scale distorted images of remote galaxies nested like Matryoshka dolls within the larger-scale lens distortions in each cluster's core, where the most massive galaxies reside.

This unexpected discovery means there is a discrepancy between these observations and theoretical models of how dark matter should be distributed in galaxy clusters. It could signal a gap in astronomers' current understanding of the nature of dark matter.