We perform a statistical weak lensing analysis of dark matter profiles around tracers of halo mass from galactic- to cluster-size halos .
In this analysis we use 170 640 isolated \sim L _ { * } galaxies split into ellipticals and spirals , 38 236 groups traced by isolated spectroscopic Luminous Red Galaxies ( LRGs ) and 13 823 MaxBCG clusters from the Sloan Digital Sky Survey ( SDSS ) covering a wide range of richness .
Together these three samples allow a determination of the density profiles of dark matter halos over three orders of magnitude in mass , from 10 ^ { 12 } M _ { \odot } to 10 ^ { 15 } M _ { \odot } .
The resulting lensing signal is consistent with an NFW or Einasto profile on scales outside the central region .
In the inner regions , uncertainty in modeling of the proper identification of the halo center and inclusion of baryonic effects from the central galaxy make the comparison less reliable .
We find that the NFW concentration parameter c _ { 200 b } decreases with halo mass , from around 10 for galactic halos to 4 for cluster halos .
Assuming its dependence on halo mass in the form of c _ { 200 b } = c _ { 0 } ( M / 10 ^ { 14 } h ^ { -1 } M _ { \odot } ) ^ { - \beta } we find c _ { 0 } = 4.6 \pm 0.7 ( at z = 0.22 ) and \beta = 0.13 \pm 0.07 , with very similar results for the Einasto profile .
The slope ( \beta ) is in agreement with theoretical predictions , while the amplitude is about two standard deviations below the predictions for this mass and redshift , but we note that the published values in the literature differ at a level of 10-20 % and that for a proper comparison our analysis should be repeated in simulations .
We compare our results to other recent determinations , some of which find significantly higher concentrations .
We discuss the implications of our results for the baryonic effects on the shear power spectrum : since these are expected to increase the halo concentration , the fact that we see no evidence of high concentrations on scales above 20 % of the virial radius suggests that baryonic effects are limited to small scales , and are not a significant source of uncertainty for the current weak lensing measurements of the dark matter power spectrum .