Effect of Gravitational Lensing on Measurements of the Sunyaev-Zel'dovich Effect

Abstract

The Sunyaev-Zel'dovich (SZ) effect of a cluster of galaxies is usually measured after background radio sources are removed from the cluster field. Gravitational lensing by the cluster potential leads to a systematic deficit in the residual intensity of unresolved sources behind the cluster core relative to a control field far from the cluster center. As a result, the measured decrement in the Rayleigh-Jeans temperature of the cosmic microwave background is overestimated. We calculate the associated systematic bias which is inevitably introduced into measurements of the Hubble constant using the SZ effect. For the cluster A2218, we find that observations at 15 GHz with a beam radius of 0'.4 and a source removal threshold of 100 microJy underestimate the Hubble constant by 6-10%. If the profile of the gas pressure declines more steeply with radius than that of the dark matter density, then the ratio of lensing to SZ decrements increases towards the outer part of the cluster.

11 pages, 3 figures, submitted to ApJL

References in corpus (3)

• The Angular Two-Point Correlation Function for the FIRST Radio Survey
• A Weak Gravitational Lensing Analysis of Abell 2390
• Gravitational Lensing of the X-Ray Background by Clusters of Galaxies

Cited by in corpus (8)

• Cosmology with the Sunyaev-Zel'dovich Effect
• Radio Sources in Galaxy Clusters: Radial Distribution, and 1.4 GHz and K-band Bivariate Luminosity Function
• Radio Sources in Galaxy Clusters at 28.5 GHz
• Multi-frequency imaging of the galaxy cluster Abell 2163 using the Sunyaev-Zel'dovich Effect
• Constraints in Cosmological Parameter Space from the Sunyaev-Zel'dovich Effect and Thermal Bremsstrahlung
• Submillimeter galaxies behind the Bullet Cluster (1E 0657-56)
• On the Cluster Sunyaev-Zel'dovich Effect and Hubble Constant
• Weak lensing of the Sunyaev-Zel'dovich sky