1611.10326
Weak lensing magnification in the Dark Energy Survey Science Verification Data
Garcia-Fernandez, et al
In this paper the effect of WL magnification on galaxy number counts is studied by cross-correlating the positions of 2 galaxy samples, separated by redshift, using data from the DES SV data set. The analysis is carried out for 2 photometrically-selected galaxy samples, with mean photometric redshifts in the 0.2<z<0.4 and 0.7<z<1.0 ranges, in the riz bands. A signal is detected with a 3.5 sigma significance level in each of the bands tested, and is compatible with the magnification predicted by the LCDM model. After an extensive analysis, it cannot be attributed to any known systematic effect. The detection of the magnification signal is robust to estimated uncertainties in the outlier rate of the photometric redshifts, but this will be an important issue for use of photometric redshifts in magnification measurements from larger samples. In addition to the detection of the magnification signal, a method to select the sample with the maximum signal-to-noise is proposed and validated with data.
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