Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO

Understand

We perform an exhaustive follow-up analysis of a subsolar-mass (SSM) gravitational wave (GW) candidate reported by Phukon et al.

• from the second observing run of Advanced LIGO.
• This candidate has a reported signal-to-noise ratio (SNR) of $8.6$ and false alarm rate of $0.41$ yr which are too low to claim a clear gravitational-wave origin.
• When improving on the search by using more accurate waveforms, extending the frequency range from 45 Hz down to 20 Hz, and removing a prominent blip glitch, we find that the posterior distribution of the network SNR lies mostly below the search value, with the $90\%$ confidence interval being $7.94^{+0.70}_{-1.05}$.