Before their trajectory curves towards the galaxy, they already manage to pass the galaxy.The Role of Dynamical FrictionThus, dark matter particles do not get in the galaxy, but rather move behind the galaxy (see video below). Behind the galaxy, for that reason, the density of matter boosts, and this leads to a slowdown of the galaxy– a phenomenon called dynamical friction. When particles pass slowly, the density of matter increases closer to the galaxy, causing it to slow down more.The green dot represents a galaxy, and the upper panels reveal the movement of dark matter particles past the galaxy (if a galaxy exists in the matching panel). Of course, a lot depends on how far to look in the external parts of a galaxy and what level of lopsidedness considers a galaxy lopsided.Also, the lopsided shape of a galaxy might not be triggered just by dynamical friction. In such scenarios, the shape of the galaxy will take a couple of billion years to recover.Conclusion and Future ResearchThus, to measure the velocities of dark matter, we require a lopsided galaxy that is as isolated from other galaxies as possible.
Before their trajectory curves towards the galaxy, they already handle to pass the galaxy.The Role of Dynamical FrictionThus, dark matter particles do not go into the galaxy, however instead move behind the galaxy (see video listed below). When particles pass slowly, the density of matter increases closer to the galaxy, causing it to slow down more.The green dot represents a galaxy, and the upper panels show the motion of dark matter particles past the galaxy (if a galaxy exists in the matching panel). In such circumstances, the shape of the galaxy will take a few billion years to recover.Conclusion and Future ResearchThus, to determine the speeds of dark matter, we need a lopsided galaxy that is as separated from other galaxies as possible.
