Recent developments in deep learning techniques have offered an alternative
and complementary approach to traditional matched filtering methods for the
identification of gravitational wave (GW) signals. The rapid and accurate
identification of GW signals is crucial for the progress of GW physics and
multi-messenger astronomy, particularly in light of the upcoming fourth and
fifth observing runs of LIGO-Virgo-KAGRA. In this work, we use the 2D U-Net
algorithm to identify the time-frequency domain GW signals from stellar-mass
binary black hole (BBH) mergers. We simulate BBH mergers with component masses
from 5 to 80 M⊙​ and account for the LIGO detector noise. We find that
the GW events in the first and second observation runs could all be clearly and
rapidly identified. For the third observation run, about 80% GW events could
be identified and GW190814 is inferred to be a BBH merger event. Moreover,
since the U-Net algorithm has advantages in image processing, the
time-frequency domain signals obtained through U-Net can preliminarily
determine the masses of GW sources, which could help provide the mass priors
for future parameter inferences. We conclude that the U-Net algorithm could
rapidly identify the time-frequency domain GW signals from BBH mergers and
provide great help for future parameter inferences.Comment: 11 pages, 9 figure