Impact of correlated magnetic noise on directional stochastic gravitational-wave background searches

• Main Authors: Venikoudis, Stavros, De Lillo, Federico, Janssens, Kamiel, Suresh, Jishnu, Bruno, Giacomo
• Format: Journal Article
• Language: English
• Published: 18-11-2024
• Subjects: Physics - General Relativity and Quantum Cosmology
• DOI: 10.48550/arxiv.2411.11746

One potential factor that could impede searches for the stochastic
gravitational-wave background (SGWB), arising from the incoherent superposition
of a multitude of weak and unresolvable gravitational-wave signals in the
Universe, is correlated magnetic noise at Earth-scale distances, such as the
Schumann resonances. As the sensitivity of terrestrial detectors to SGWBs
increases, these effects are expected to become even more pronounced,
emphasizing the importance of considering correlated noise sources in SGWB
searches. In this study, we explore for the first time the impact of this class
of noise on anisotropic SGWB searches. We focus on the low-frequency range of
20-200 Hz with a resolution of 1/32 Hz, using data from the LEMI-120 and
Metronix MFS-06e magnetometers, located at the sites of the Advanced LIGO and
Advanced Virgo interferometers, respectively, during the third observing run.
These measurements were then compared with the directional upper limit derived
from gravitational-wave data collected during the third observing run of the
LIGO-Virgo-KAGRA collaboration. The results indicate that the magnetic noise
correlations are below the interferometers' sensitivity level during the O3
observing run. The potential impact of magnetic correlations on the Advanced
LIGO detectors has also been investigated at the A+ design sensitivity level.