[krylon]

I see. In the back of my mind there was still the possibility that it could have been created by two black holes merging or a neutron star falling into a black hole.

... I wonder, if a neutron star and a black hole merge, does the neutron star get shredded early enough to form an accretion disk, or does it just disappear like a marble falling into a hole?

For some reason my imagination is quite lively today, these questions just keep popping up in my head like banner ads. ;-)