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arXiv · 1003.5219

A proposal on the galaxy intrinsic alignment self-calibration in weak lensing surveys

Pengjie Zhang
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Abstract

The galaxy intrinsic alignment causes the galaxy ellipticity-ellipticity power spectrum between two photometric redshifts to decrease faster with respect to the redshift separation $Δz^P$, for fixed mean redshift. This offers a valuable diagnosis on the intrinsic alignment. We show that the distinctive dependences of the GG, II and GI correlations on $Δz^P$ over the range $|Δz^P|\la 0.2$ can be understood robustly without strong assumptions on the intrinsic alignment. This allows us to measure the intrinsic alignment within each conventional photo-z bin of typical size $\ga 0.2$, through lensing tomography of photo-z bin size $\sim 0.01$. Both the statistical and systematical errors in the lensing cosmology can be reduced by this self-calibration technique.

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Pengjie Zhang. 2010-07-14. A proposal on the galaxy intrinsic alignment self-calibration in weak lensing surveys. https://doi.org/10.1111/j.1745-3933.2010.00893.x

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