STEP simulations. We assume a 2% redshift-independent bias in the shape measurements, which translates into a scale-independent 4% error in the data vector, and repeat the joint analysis. The resulting combined contour shifts upwards along the WMAP5+BAO+SNe degeneracy in agreement with the discussion in Sect. 3.2. As seen in Fig. \[fig:testWLdata\] (left panel, solid lines), this small bias is enough for the evidence of massless neutrinos to be lost and we obtain at the 95% C.L. : $$\sum m_\nu<0.53~eV.$$

Other sources of errors that can affect cosmic-shear cosmological constraints are: contamination from intrinsic alignments, in particular shear-shape correlations [@hirataseljak] for no precise theoretical modeling yet exists; uncertainties in the photometric redshifts; and extra PSF residuals not predicted by the STEP simulations. Modelling of some of the CFHTLS-T0003 systematics is included in the analysis of Kilbinger [et al. ]{}(2008). Here we consider the rougher approach of marginalizing over a scale-independent calibration factor, accounting for all possible sources of biases, with the goal of finding a threshold of contamination above which the CFHTLS data do not improve the combined constraints.

![image](11077fg5a.ps){width="5.9cm"} ![image](11077fg5b.ps){width="5.9cm"} ![image](11077fg5c.ps){width="5.9cm"}

We find a threshold of 25% for the aperture mass dispersion data. The corresponding combined contour in the $(\omega_\nu,\omega_{\mathrm{cdm}})$ 