As the number of gravitational wave observations has increased in recent
years, the variety of sources has broadened. Here we investigate whether it is
possible for the current generation of detectors to distinguish between very
short-lived gravitational wave signals from mergers between high-mass black
holes, and the signal produced by a close encounter between two black holes
which results in gravitational capture, and ultimately a merger. We compare the
posterior probability distributions produced by analysing simulated signals
from both types of progenitor events, both under ideal and realistic scenarios.
We show that while, under ideal conditions it is possible to distinguish both
progenitors, under more realistic conditions they are indistinguishable. This
has important implications for the interpretation of such short signals, and we
therefore advocate that these signals be the focus of additional investigation
even when satisfactory results have been achieved from standard analyses.
