"Now, the tale has taken a deeper turn into the unknown, thanks to an analysis of the normal matter at the centres of 28 galaxies of all shapes and sizes. The study shows that there is always five times more dark matter than normal matter where the dark matter density has dropped to one-quarter of its central value. The finding goes against expectations because the ratio of dark to normal matter should depend on the galaxy's history â" for example, whether it has merged with another galaxy or remained isolated during its entire existence. Mergers should skew the ratio of dark to normal matter on an individual basis."
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