At the centre of spiral galaxies there is a vast spherical region made up of dark matter particles. This region has two defining characteristics. A density that is constant out to a certain radius. It amazingly expands over time and the density decreases. This suggests the existence of a direct interaction between the elementary particles. It makes up the dark matter halo and protons, electrons, neutrons, and photons.
Scientists anticipated that this hypothesis is in direct conflict with the current prevailing theory used to describe the universe. It is known as Lambda-Cold Dark Matter. It posits that particles of cold dark matter are inert. It does not interact with any other particle except gravitationally. The study has been published in the Astronomy and Astrophysics journal.
It studied a large number of distant galaxies. It is some seven billion light-years away. Scientists took a new look at one of the greatest mysteries of modern physics. According to scientists the new research represents a step forward in our understanding of dark matter. The elusive element in our universe has been theorized based on its demonstrable effects on heavenly bodies. It is yet to be directly proven. It is despite any number of targeted astrophysical observations. The experiments set up for the purpose in dedicated underground laboratories.
Studying dark matter in distant galaxies
Dark matter makes up nearly 84% of the mass in the cosmos. But until now, study has focused on galaxies near to our own. This trait had already been observed in studies examining nearby galaxies. Some of which were also the work of SISSA.
The new research has revealed, the central region had something that was wholly unexpected. It is within the context of the so-called “standard model of cosmology.” It is very difficult to be explained if the dark matter particles did not interact. The Lambda-CDM model has pointed it.
A slow yet inexorable process
This process would create a spherical region of consistent density within the dark matter halo. It will increase proportionately over time and finally reach those of the galactic stellar disc.