Bibcode
DOI
Allard, E. L.; Peletier, R. F.; Knapen, J. H.
Bibliographical reference
The Astrophysical Journal, Volume 633, Issue 1, pp. L25-L28.
Advertised on:
11
2005
Journal
Citations
25
Refereed citations
23
Description
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 Hβ emission is strongest in the ring, along two
curved bar dust lanes and at the ends of the bar. The Mg b
absorption-line strength shows a younger population of stars within the
ring than in 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 dust lanes. Low gas dispersion is correlated
spatially with the Hβ emission. We thus see stars being formed from
cold (low-dispersion) gas that is being channeled inward along the dust
lanes 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.