Testing the Viewing Angle Hypothesis for Short GRB with LIGO events

It has been suggested that short gamma ray bursts (GRBs) have shorter or undetectable spectral lags than long GRB because in the former, the observer’s line of sight makes a larger angle with the GRB jet axis than for the latter. It is proposed that simultaneous gravitational wave - short GRB events could provide a simple test of this hypothesis. Multimessenger astronomy eventually may test whether event horizons are a necessary ingredient for GRB.