[songeater]

Shouldn't the "sonic boom" here provide good data as to the existence of dark matter (akin to the Bullet cluster)? Anyone on hn with good background care to comment? Don't see anything in the article about it, but would think is one of the most significant experimental goals from detecting these sorts of collisions.

[dotnet00]

My understanding is that, yes, the way matter in a galaxy merger behaves acts as strong evidence for the existence of dark matter and the theory that it's made of something that interacts weakly with normal matter.