Let's try to get something started here again.
Here's an article about the discovery of the merging of two massive black holes. There are two interesting aspects of this report. First, the discovery was made by the detection of gravity waves by the high tech LIGO and VIRGO gravity wave detectors that have been in operation only since 2015. And second, both of the parent black holes, as well as the resultant behemoth of the merger are in an intermediate, forbidden zone for mass.