Anyone who does not remotely understand science would argue that we have a “good” understanding of dark matter. Even the name betrays how little we know about it. However, a new analysis using the Hubble Space Telescope of aging suggests that we know less than we think. Hubble’s analysis of Dark Matter shows more in places we didn’t expect, to do things we didn’t expect.
Dark matter is difficult to study because it does not produce, absorb, or reflect electromagnetic radiation. For all intents and purposes, it is invisible to us. However, we can infer the presence of dark matter on the basis of its gravitational effects, and it is that a team led by Massimo Menegetti of the National Institute for Astrophysics in Italy analyzed dark matter in 11 large galaxy clusters.
Scientists believe that dark matter may be the highest for the “missing mass” of the universe. It can account for 85 percent of the universe, and we cannot see it. If we ever want to understand dark matter, we have to start somewhere. Gravity lensing is as good a place as it is – scientists are able to estimate the amount of dark matter in a region of space that compares estimated gravity to visible gravity with actual observed gravity. Even light cannot emit from gravity, so dark matter heavy areas will show gravitational lensing as the light bends around them.
Menegaty states that galaxy clusters are ideal places to study darker colors. The team generates simulations of the expected lensing effect in the lab, and is then compared with reality via Hubble. By and large, the models are accurate – the team observed lensing around the cluster as predicted. However, the study also revealed lensing around individual galaxies that was not predicted in the model. This may mean that the amount of dark matter in those galaxies may be 10 times or more than believed.
To confirm these findings, the team conducted spectroscopic observations of suspicious galaxies. Visions of visible light allowed scientists to calculate the velocity of orbiting stars, which is one of the few ways we can measure dark matter. This analysis confirmed that the current model had a much darker case than predicted.
We do not know what this means, but any discrepancy between model and reality is an opportunity to improve the model. This allows us to know what Dark Matter is.