Star Formation at z=2.481 in the Lensed Galaxy SDSS J1110+6459: Star
  Formation down to 30 parsec scales
  We present measurements of the surface density of star formation, the
star-forming clump luminosity function, and the clump size distribution
function, for the lensed galaxy SGAS J111020.0+645950.8 at a redshift of
z=2.481. The physical size scales that we probe, radii r=30--50 pc, are
considerably smaller scales than have yet been studied at these redshifts. The
star formation surface density we find within these small clumps is consistent
with surface densities measured previously for other lensed galaxies at similar
redshift. Twenty-two percent of the rest-frame ultraviolet light in this lensed
galaxy arises from small clumps, with r<100 pc. Within the range of overlap,
the clump luminosity function measured for this lensed galaxy is remarkably
similar to those of z~0 galaxies. In this galaxy, star-forming regions smaller
than 100 pc---physical scales not usually resolved at these redshifts by
current telescopes---are important locations of star formation in the distant
universe. If this galaxy is representative, this may contradict the theoretical
picture in which the critical size scale for star formation in the distant
universe is of order 1 kiloparsec. Instead, our results suggest that current
telescopes have not yet resolved the critical size scales of star-forming
activity in galaxies over most of cosmic time.
