How to study something invisible? This is the challenge facing astronomers studying dark matter. Although dark matter comprises 85% of all matter in the universe, it does not interact with light. This can only be seen by the gravitational influence it has on light and other things. To make matters worse, attempts to directly detect dark matter on Earth have so far failed.
Despite the elusive quality of the dark material, we learned many things about it. We know that it is not only dark but also cold. As a result, it moves together, forming the seeds of galaxies. It often forms haloes around galaxies, forming the bulk of a galaxy. However, there are still many unanswered questions about dark matter, so astronomers often create new models for dark matter and compare them with observations to test their accuracy.
One way to do this is with sophisticated computer simulations. Recently a team from the Harvard & Smithsonian Astrophysics Center conducted an extensive simulation of the universe of dark matter, and this has yielded some surprising results.
The accuracy of the simulation of any dark object depends on the assumptions you make about the dark object. In this case, the matrix is assumed to be made of dark matter Massive particles (WIMPs) interact weakly With 100 times the mass of a proton. One of the most popular theories for dark matter is WIMPs. Similar computer simulations of the WIMP dark object have been made before. However, it was exceptionally high, simulating features on the order of thirty orders.
In this simulation, dark matter is formed in the haloes surrounding galaxies. But interestingly, haloes have formed at all masses, from small, planetary-mass haloes to galaxies, to massive haloes that form around galaxies. These haloes have a similar structure where they are much denser towards their center and spread further at their edges. The fact that it occurs on all levels makes it an obvious aspect of the dark matter.
Although small haloes are too small to be detected by the gravitational influence of light, they can tell us how dark matter interacts with itself. One idea about dark matter is that when particles of dark matter collide, they emit gamma radiation. Some gamma-ray observations a Excess gamma rays coming from the center of our galaxy, which may be caused by dark matter. In this particular model, most gamma radiation produced by dark matter comes from small haloes. Since the size of a halo affects the energy spectrum of gamma rays, this model makes gamma-ray excess specific predictions that we should see in galaxies and other galaxies.
The dark matter is one of the biggest unresolved issues in modern astronomy. We like to detect it directly, and until that happens, simulations like this are one of our most powerful tools to better understand the dark matter.
Note: Wang, J., Bose, S., Frank, C.S. et al. “The global system of dark objects is in the mass range of 20 orders. ” Natural 585.7823 (2020): 39-42.