Highly spinning and aligned binary black hole merger in the Advanced LIGO first observing run

The LIGO Scientific Collaboration has generously made the data from its First Observing Run (O1) publicly available, including that from the two history-making observations of gravitational waves from binary black hole merger events GW150914 and GW151226. In this paper, the authors apply an independent search pipeline to the aLIGO O1 data to search for additional gravitational wave events and argue for the existence of a previously undiscovered BH merger event, GW151216.