  The SAURON integral field spectrograph was used to observe the central area
of the barred spiral galaxy M100 (NGC 4321). M100 contains a nuclear ring of
star formation, fueled by gas channeled inward by the galaxy's bar. We present
maps of emission line strengths, absorption line strength indices, and the gas
velocity dispersion across the field. The H beta emission is strongest in the
ring, along two curved bar dustlanes and at the ends of the bar. The Mg b
absorption line strength shows a younger population of stars within the ring as
compared to the surrounding area. The gas velocity dispersion is notably
smaller than elsewhere in the field both in the ring and along the leading edge
of the dustlanes. Low gas dispersion is correlated spatially with the H beta
emission. We thus see stars being formed from cold (low dispersion) gas which
is being channeled inward along the dustlanes under the influence of a large
bar, and accumulated into a ring near the location of the inner Lindblad
resonances. This lends further strong support to the interpretation of nuclear
rings in barred galaxies as resonance phenomena.
