Virgo interferometer calibration and h(t) strain reconstruction uncertainty during the O4 observing run (Cervane Grimaud, CEA Irfu)

par Cervane Grimaud (LAPP)

lundi 29 juin 2026, 14:00 → 16:00 Europe/Paris

amphi Charpak

Since the first gravitational wave detection in 2015, ground-based interferometer sensitivities have significantly improved, requiring highly precise calibration to ensure accurate reconstruction of the h(t) strain signal. This talk will outline the Virgo interferometer calibration steps performed in preparation of the O4 run and how the precision was greatly improved compared to the previous runs. It will also discuss the monitoring of the h(t) strain reconstruction during the run and in particular describing the newly developed frequency-dependent bias and uncertainty computation method developped for O4 and the resulting online unbiasing of the h(t) strain.