"the emissions are 100 billion times brighter than those from the Sun"
So they're getting x-rays from a merger that are stupendously bright. Did they point an optical telescope there to see if anything was visible ?
How about infra-red ? If the two neutron stars don't have nuclear fusion, they should certainly be radiating heat like crazy.
Of course, if they've become a black hole, then the source has to come from the jet, but couldn't the jet be visible if it 10,000 billion kilometers long ?
EDIT : after a short search, I found this article that details nicely all the important things about this merger, and there are many. But nothing on the jet.