We use a temperature map of the cosmic microwave background ( CMB ) obtained using the South Pole Telescope at 150 GHz to construct a map of the gravitational convergence to z \sim 1100 , revealing the fluctuations in the projected mass density .
This map shows individual features that are significant at the \sim 4 \sigma level , providing the first image of CMB lensing convergence .
We cross-correlate this map with Herschel /SPIRE maps covering 90 square degrees at wavelengths of 500 , 350 , and 250 \micro m. We show that these submillimeter-wavelength ( submm ) maps are strongly correlated with the lensing convergence map , with detection significances in each of the three submm bands ranging from 6.7 to 8.8 \sigma .
We fit the measurement of the cross power spectrum assuming a simple constant bias model and infer bias factors of b = 1.3 - 1.8 , with a statistical uncertainty of 15 \% , depending on the assumed model for the redshift distribution of the dusty galaxies that are contributing to the Herschel /SPIRE maps .