We present first results of a study of the submillimetre ( rest frame far-infrared ) properties of z \sim 3 Lyman Break Galaxies ( LBGs ) and their lower-redshift counterparts BX / BM galaxies , based on Herschel -SPIRE observations of the Northern field of the Great Observatories Origins Deep Survey ( GOODS-N ) .
We use stacking analysis to determine the properties of LBGs well below the current limit of the survey .
Although LBGs are not detected individually , stacking the infrared luminous LBGs ( those detected with Spitzer at 24 \mu m ) yields a statistically significant submm detection with mean flux \langle S _ { 250 } \rangle = 5.9 \pm 1.4 mJy confirming the power of SPIRE in detecting UV-selected high-redshift galaxies at submillimetre wavelengths .
In comparison , the Spitzer 24 \mu m detected BX / BM galaxies appear fainter with a stacked value of \langle S _ { 250 } \rangle = 2.7 \pm 0.8 mJy .
By fitting the Spectral Energy Distributions ( SEDs ) we derive median infrared luminosities , L _ { IR } , of 2.8 \times 10 ^ { 12 } L _ { \odot } and 1.5 \times 10 ^ { 11 } L _ { \odot } for z \sim 3 LBGs and BX / BMs , respectively .
We find that L _ { IR } estimates derived from present measurements are in good agreement with those based on UV data for z \sim 2 BX / BM galaxies , unlike the case for z \sim 3 infrared luminous LBGs where the UV underestimates the true L _ { \bf { IR } } .
Although sample selection effects may influence this result we suggest that differences in physical properties ( such as morphologies , dust distribution and extent of star-forming regions ) between z \sim 3 LBGs and z \sim 2 BX / BMs may also play a significant role .