Study of correlations between seismic data and Virgo's gravitational-wave detector data

It is expected that noise produced by terrestrial gravity fluctuations will start to limit the sensitivity of the ground-based, gravitational-wave detector Virgo in coming observation runs. A system is under preparation at Virgo to cancel this noise, also known as Newtonian noise. This Newtonian noise cancelation system requires the deployment of seismometer arrays inside the Virgo buildings. Crucial for the design of such a system is a detailed understanding of correlations between ground vibrations and Virgo’s gravitational waves detector data. In this article, we present first analyses of such correlations observed with a tiltmeter. We find that revealed correlations are stronger than predicted by possible pure gravitational coupling,which is pointing towards additional coupling mechanisms. These findings might impact the design of the Newtonian noise cancelation system if the additional couplings cannot be mitigated.