Line-robust statistics for continuous gravitational waves: safety in the case of unequal detector sensitivities

Understand

The multi-detector F-statistic is close to optimal for detecting continuous gravitational waves (CWs) in Gaussian noise.

• However, it is susceptible to false alarms from instrumental artefacts, for example quasi-monochromatic disturbances ('lines'), which resemble a CW signal more than Gaussian noise.
• In a recent paper [Keitel et al 2014, PRD 89 064023], a Bayesian model selection approach was used to derive line-robust detection statistics for CW signals, generalising both the F-statistic and the F-statistic consistency veto technique and yielding improved performance in line-affected data.
• Here we investigate a generalisation of the assumptions made in that paper: if a CW analysis uses data from two or more detectors with very different sensitivities, the line-robust statistics could be less effective.