Data quality in gravitational wave bursts and inspiral searches in the second Virgo Science Run

In July 2009, Virgo started its second Science Run (VSR2) jointly with the LIGO detectors (S6). Great efforts have been made to understand the new sources of noise disturbance in Virgo data due to the detector or its environment. This understanding is crucial in order to reject noise events that could mimic a genuine gravitational wave (GW). One of the great challenges of VSR2 was to be able to monitor and deliver data quality information with low latency so that the online burst and inspiral GW searches could generate event candidates for follow-up studies. This paper reviews the sources of noise which have been identified and explains how it was possible to discard the associated noise events from the data. Finally, it presents the effect of data quality vetoes on Virgo triggers.