Bibcode
Mazzuca, L. M.; Knapen, J. H.; Regan, Michael W.; Veilleux, Sylvain
Referencia bibliográfica
THE EVOLUTION OF STARBURSTS: The 331st Wilhelm and Else Heraeus Seminar. AIP Conference Proceedings, Volume 783, pp. 182-188 (2005).
Fecha de publicación:
8
2005
Número de citas
0
Número de citas referidas
0
Descripción
Nuclear rings are characterized by their high star formation rates, and
are believed to be the products of gas inflow towards the inner regions
of spiral galaxies. We present first results from a statistical survey
of these rings, aimed to provide an insight into their triggering
mechanisms and star formation properties. We gathered photometric data
for 22 nuclear star-forming rings from a larger Hα survey of
nearby spirals, of which we highlight three interesting cases (NGC 1343,
NGC 1530, and NGC 5953). The high-quality images reveal that the rings
are comprised of several distinct star-forming clusters within a few
kiloparsecs of the nucleus. We analyzed each nuclear ring to obtain
morphological parameters such as ellipticity, position angle, and size.
We then compute the equivalent widths of each Hα emitting (HII)
region forming the nuclear ring. Using modern population synthesis
models, we convert the equivalent widths into an estimate of the age of
each cluster. In general, ages range from 1 Myr to 10 Myrs throughout
the rings. We compare the ages to the positions along each ring to
detect possible age-related patterns. Where a bar exists in the host
galaxy, we determine the approximate intersection points of the bar to
the ring to probe whether the youngest hotspots occur near this
intersection. We find that three rings from the sample show age
gradients or bisymmetries along the plane of the ring, and in one case
the youngest cluster does indeed intersect with one of the bar's
interaction points to the ring.