A new method of measuring the cluster peculiar velocity power spectrum

Understand

We propose to use spatial correlations of the kinetic Sunyaev-Zeldovich (KSZ) flux as an estimator of the peculiar velocity power spectrum.

• In contrast with conventional techniques, our new method does not require measurements of the thermal SZ signal or the X-ray temperature.
• Moreover, this method has the special advantage that the expected systematic errors are always sub-dominant to statistical errors on all scales and redshifts of interest.
• We show that future large sky coverage KSZ surveys may allow a peculiar velocity power spectrum estimates of an accuracy reaching ~10%.