fluffy dark matter

Watched Dr Laura Parker's talk on the dark universe recorded at the 26 Sep RASC meeting. She's an excellent speaker. I was most impressed at her answers in the Q&A after. Parker clearly has a very deep knowledge of this incredible domain.

Chris asked an interesting question (around the 44 minute mark). He noted an inverse relationship between the luminous and dark matter in the rotational speed graphic. He asked if dark matter doesn't like regular matter or doesn't want to occupy the same space.

Parker shared that there's a good relationship with matter distribution. But at large radii the dark matter becomes more prevalent than the visible matter. And there's good physics to explain this. The regular matter collapses and sinks to the middle of the galactic region so to form the galaxy and in the process radiates energy. Meanwhile the big ball of dark matter does not collapse, in can't shrink, it cannot give off radiation, so the dark matter remains fluffy and big.

I took lots of questions from Rhonda hopefully clarifying things about dark matter and dark energy.