New findings in dark matter physics could prompt brand-new model of the 'real' universe

The Universe is majorly made up of dark matter and surprisingly scientists seem to know little about it. It cannot be seen through light or any form of electromagnetism but it does emit gravitational forces without which galaxies and clusters of galaxies would fly away from each other. Now, a new study, based on observations of distant galaxy clusters seen by the Hubble Space Telescope and the Very Large Telescope in Chile has revealed that dark matter behaves a bit differently than what is predicted by simulations, indicating that our understanding of dark matter may need revision. According to a report by Yale News, research by Yale astrophysicist Priyamvada Natarajan and a team of international researchers from analysis of Hubble Space Telescope images of massive galaxy clusters, smaller dollops of dark matter associated with cluster galaxies were significantly more concentrated than earlier thought. This implies that there may be something missing in scientists’ understanding of dark matter. [caption id=“attachment_8828451” align=“alignnone” width=“1280”] Hubble Space Telescope image of the massive galaxy cluster MACSJ1206 with the distortions produced by light bending and the dark matter map generated from these lensing effects. Image Credit: NASA/ESA-Hubble/G. Caminha/M. Meneghetti/P. Natarajan/CLASH team/M. Kornmesser[/caption] Senior author of the study Natarajan said that there is a feature of the real universe that one cannot simply capture in current theoretical models, adding that the discovery could “signal a gap” in the current understanding of the nature of dark matter and its properties. As per the report, astronomers are usually able to map the distribution of dark matter in clusters through gravitational lensing. The higher the concentration of dark matter in a cluster, the more dramatic is the observed lensing effect. Researchers made use images from NASA’s Hubble Space Telescope, coupled with spectroscopy from the European Southern Observatory’s Very Large Telescope, to produce high-fidelity dark-matter maps. The 3D maps showed presence of dark matter hills, mounds, and valleys. As per researchers, the peaks are the dollops of dark matter associated with individual cluster galaxies. [caption id=“attachment_8828461” align=“alignnone” width=“800”] Hubble image of the lensing cluster MACSJ1206. Inset shows the spatial distribution of dark matter — the heaped mountain range dotted with small peaks. Image Credit: NASA/ESA-Hubble/G. Caminha/M. Meneghetti/P. Natarajan/CLASH team/M. Kornmesser[/caption] The high quality of the images allowed the researchers to test whether these dark matter landscapes matched theory-based computer simulations of galaxy clusters with similar masses, located at roughly the same distances. They found that the simulations did not show any of the same level of dark-matter concentration on the smallest scales. As per Natarajan a key goal of the research has been the discovery that there is something missing in the new theory and that it “points the way to a brand-new model, which will have more explanatory power.” The results of the study were published in the journal Science.