Abstract:
We present the first galaxy-galaxy lensing measurement from ~4200 square degrees of Dark Energy Camera Legacy Survey (DECaLS) DR3 data. Using the galaxy shapes of DECaLS galaxies, we extract the galaxy-galaxy lensing signals around foreground spectroscopic selected LOW-Z galaxies from SDSS-III BOSS DR12 and redMaPPer clusters. We perform a number of null tests on the shear catalogs and quantify resulting systematic uncertainties. We then constrain the stellar-to-halo mass ratio, especially for the massive dark matter halos.