Evidence of Lensing of the Cosmic Microwave Background by Dark Matter Halos

Understand

We present evidence of the gravitational lensing of the cosmic microwave background by $10^{13}$ solar mass dark matter halos.

• Lensing convergence maps from the Atacama Cosmology Telescope Polarimeter (ACTPol) are stacked at the positions of around 12,000 optically-selected CMASS galaxies from the SDSS-III/BOSS survey.
• The mean lensing signal is consistent with simulated dark matter halo profiles, and is favored over a null signal at 3.2 sigma significance.
• This result demonstrates the potential of microwave background lensing to probe the dark matter distribution in galaxy group and galaxy cluster halos.