I wonder if the gravitation waves stretches the Space-time in such a way that it takes 2 seconds longer for the photons of GRB to travel "on top of it" and reach earth.
By davidhydes comment [1] it is because the gamma burst actually happens after the merger. It is caused by the ejected mass slowing down due to friction.
My layman's interpretation is that this is cherenkov radiation on an astronomical scale, though that suggests it is caused by charged particles, which neutrons aren't.
My layman's interpretation is that this is cherenkov radiation on an astronomical scale, though that suggests it is caused by charged particles, which neutrons aren't.
[1] https://news.ycombinator.com/item?id=15484357