Journal article

Detection of enhancement in number densities of background galaxies due to magnification by massive galaxy clusters

I Chiu, JP Dietrich, J Mohr, DE Applegate, BA Benson, LE Bleem, MB Bayliss, S Bocquet, JE Carlstrom, R Capasso, S Desai, C Gangkofner, AH Gonzalez, N Gupta, C Hennig, H Hoekstra, A von der Linden, J Liu, M McDonald, CL Reichardt Show all



We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE-) inferred masses in a sample of 19 galaxy clusters with median redshift z ≃ 0.42 selected from the South Pole Telescope SPT-SZ survey. These clusters are observed by the Megacam on the Magellan Clay Telescope though gri filters. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts zmedian ≃ 0.9 (low-z background) and zmedian ≃ 1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3σ and 1.3σ for the low..

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University of Melbourne Researchers


Awarded by Transregio programme 'The Dark Universe'

Awarded by German Federal Ministry of Economics and Technology (BMWi) through DLR

Awarded by Australian Research Council's Discovery Projects scheme

Awarded by National Science Foundation

Awarded by NSF Physics Frontier Center

Awarded by Office of Polar Programs (OPP)

Funding Acknowledgements

We acknowledge the support by the DFG Cluster of Excellence 'Origin and Structure of the Universe' and the Transregio programme TR33 'The Dark Universe'. DA and TS acknowledge support from the German Federal Ministry of Economics and Technology (BMWi) provided through DLR under projects 50 OR 1210, 50 OR 1308, and 50 OR 1407. CR acknowledges support from the Australian Research Council's Discovery Projects scheme (DP150103208). The South Pole Telescope is supported by the National Science Foundation through grant ANT-0638937. Partial support is also provided by the NSF Physics Frontier Center grant PHY-0114422 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation and the Gordon and Betty Moore Foundation. Optical imaging data were obtained with Megacam on the 6.5 m Magellan Clay Telescope.