SIMBAD references

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_AY_SZ/CY_X) = -0.202±0.024 at the pivot point CY_X= 8 x 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.