Detailed observation of sixteen dwarf galaxies has brought us the first direct evidence of “dark matter heating”.
Dark matter is still… dark – as in mysterious. But scientists aren’t backing up and are still trying to figure out this cosmic mystery. One of the scientific teams recently found evidence that dark matter might be moving and possibly warm up. Their results are the first direct observation of the previously predicted phenomenon.
Justin Read from the Brittish Surrey University has studied dark matter in dwarf galaxies with his colleagues. Several reasons make dwarf galaxies very good for studying dark matter. If you don’t know, dark matter is what makes up the majority of our universe. The problem is that it doesn’t interact with matter and light the same way as regular matter does. Thus we can observe it only indirectly through gravity. And stars being created in dwarf galaxies is ideal for that.
When stars get created their intense stellar winds usually blow gases and dust from the center of the galaxy. This leads to the fact that in the center of such a galaxy there is less matter making the gravitational effects between regular matter and darker matter smaller. This then warms up the dark matter giving it energy and making it move away from the center of the galaxy.
Read and his team measured the amount of dark matter in sixteen dwarf galaxies that are quite different in the amount of stars created in them. Their research shows that dwarf galaxies where the creation of stars already ended have a higher density of dark matter in their centers compared to similar galaxies where stars are still being created. This supports the theory.
The authors of the theory think this could bring us closer to truly understanding dark matter and they want to observe a larger amount of dwarf galaxies to test the models of dark matter further.
Sources:
- https://www.surrey.ac.uk/news/dark-matter-move
- https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/sty3404/5265085
