What I don't understand here is: You have a galaxy where mass doesn't add up. There are rivaling explanations, one being that you estimated the distance wrong, the other that there is no Dark Matter. Isn't the first one the more likely one you should investigate?
> There are rivaling explanations, one being that you estimated the distance wrong, the other that there is no Dark Matter. Isn't the first one the more likely one you should investigate?
If you look back at the original paper claiming the discovery of the dark matter free galaxy, they do explore several different ways of estimating the distance and argue that they're consistent and imply the more distant value. So that's something they had considered and attempted to cross-check between different distance indicators. Later came the Trujillo paper saying essentially, hey you didn't consider "X" which argues that the galaxy is closer. The authors of the original paper then published a Research Note (that I'd liked in my original post) saying that "X" doesn't agree with the other data.
So people did consider distance errors before claiming the absence of dark matter. But getting accurate galaxy distances Is Hard and there are multiple ways to do it. The original paper considered the distance estimates they could think of and they were essentially consistent. So they did investigate that first.
