The Y SZ-YX Scaling Relation as Determined from Planck and Chandra

Sunyaev-Zeldovich (SZ) clusters surveys, such as Planck, the South Pole Telescope, and the Atacama Cosmology Telescope, will soon be publishing several hundred SZ-selected systems. The key ingredient required to transport the mass calibration from current X-ray-selected cluster samples to these SZ systems is the Y _SZ-Y_X scaling relation. We constrain the amplitude, slope, and scatter of the Y _SZ-Y_X scaling relation using SZ data from Planck and X-ray data from Chandra. We find a best-fit amplitude of ln (D ² _A Y _SZ/CY_X ) = -0.202 ± 0.024 at the pivot point CY_X = 8 × 10^-5 Mpc². This corresponds to a Y _SZ/Y_X ratio of 0.82 ± 0.024, in good agreement with X-ray expectations after including the effects of gas clumping. The slope of the relation is α = 0.916 ± 0.032, consistent with unity at ≈2.3σ. We are unable to detect intrinsic scatter, and find no evidence that the scaling relation depends on cluster dynamical state.