This is the COSMOS ACS weak lensing source catalog. The main file is called cosmosACS_sourcecatalog_2018.txt This catalog is cross matched with the L'Aigle et al 2015 photoz catalog. This is the source catalog for lensing. Quality cuts on the source catalog have already been applied. A cut on source photoz quality has also already been applied. For details about these cuts, please see Leauthaud et al. 2007. Shear calibration has already been applied. Column 8 is the inverse variance weight for a per component shear: shape_noise = 0.27 weight = 1.0/(var_e1+(shape_noise)^2) Column 4 is the redshift of a secondary peak if it exists. If you want more robust photoz's, you can limit sources to those with zp2<0. When they exist, photoz-s have been replaced with speczs. This souce catalog assumes an orientation for e1 and e2 aligned with the reference frame (x,y)=(RA,DEC). If you also want to define a lens sample in the same field, then I recommend using the l'Aigle et al 2015 photoz catalog. Please reference Leauthaud et al 2007 when you use this catalog.