First results from HerMES on the evolution of the submillimetre
  luminosity function
  We have carried out two extremely deep surveys with SPIRE, one of the two
cameras on Herschel, at 250 microns, close to the peak of the far-infrared
background. We have used the results to investigate the evolution of the
rest-frame 250-micron luminosity function out to z=2. We find evidence for
strong evolution out to a redshift of around 1 but evidence for at most weak
evolution beyond this redshift. Our results suggest that a significant part of
the stars and metals in the Universe today were formed at z<1.4 in spiral
galaxies.
