We present the first measurement of the correlation between the map of the cosmic microwave background ( CMB ) lensing potential derived from the Planck nominal mission data and z \lower 2.0 pt \hbox { $ { > \atop \hbox { \raise 4.0 pt \hbox { $ \sim$ } } } $ } 1.5 galaxies detected by the Herschel -ATLAS ( H-ATLAS ) survey covering about 600 \hbox { deg } ^ { 2 } , i.e .
about 1.4 % of the sky .
We reject the hypothesis that there is no correlation between CMB lensing and galaxy detection at a 20 \sigma significance , checking the result by performing a number of null tests .
The significance of the detection of the theoretically expected cross-correlation is found to be 10 \sigma .
The galaxy bias parameter , b , derived from a joint analysis of the cross-power spectrum and of the auto-power spectrum of the galaxy density contrast is found to be b = 2.80 ^ { +0.12 } _ { -0.11 } , consistent with earlier estimates for H-ATLAS galaxies at similar redshifts.On the other hand , the amplitude of the cross-correlation is found to be a factor A = 1.62 \pm 0.16 higher than expected from the standard model and also found by cross-correlation analyses with other tracers of the large-scale structure .
The enhancement due to lensing magnification can account for only a fraction of the excess cross-correlation signal .
We suggest that part of it may be due to an incomplete removal of the contamination of the cosmic infrared background , which includes the H-ATLAS sources we are cross-correlating with .
In any case , the highly significant detection reported here using a catalog covering only 1.4 % of the sky demonstrates the potential of CMB lensing correlations with submillimeter surveys .