Bibcode
Knapen, J. H.; Beckman, J. E.; Shlosman, I.
Bibliographical reference
American Astronomical Society, 185th AAS Meeting, #105.03; Bulletin of the American Astronomical Society, Vol. 26, p.1492
Advertised on:
12
1994
Citations
0
Refereed citations
0
Description
Barred galaxies frequently exhibit central starburst activity, typically
concentrated in circumnuclear rings. Much of direct and circumstantial
evidence speaks in favor of bar-induced fueling of star-forming activity
in these galaxies. We present results, partly preliminary, for three
galaxies which were studied through high-resolution imaging in the
optical and near-infrared (NIR), and through numerical modeling. In
particular, we have been able to reproduce the main features observed in
the central region of NGC 4321. In the NIR, we see a large-scale (4 kpc)
bar, dissected by a 1--1.3 kpc diameter oval region of strongly enhanced
star formation, formed by two tightly wound spirals. The NIR isophotes
are aligned with the bar both inside and outside the ``ring''. Two
leading armlets are seen in the NIR (K) and both culminate in regions of
intense star formation at the inner boundary of the ``ring''. The
morphology of the circumnuclear region is consistent with being
regulated by a pair of inner Lindblad resonances. We also show new
optical, NIR, and molecular data of two additional barred galaxies: NGC
1300 and NGC 6951, which have circumnuclear star-forming regions of
similar size as NGC 4321. Although these regions are more ring-like and
do not exhibit spiral structure, we show that similar mechanisms as
described for the first galaxy regulate the structure and star formation
in these two galaxies. The fact that NGC 6951 hosts a Seyfert nucleus
may provide an important test of the relevance of bar-induced inflows,
such as observed in these barred galaxies, to active galactic nuclei.
Implications and observational and theoretical prospects are discussed.