Bar-Driven Disk Evolution: Grand-Design Nuclear Spirals

Jogee, S.; Shlosman, I.; Laine, S.; Englmaier, P.; Knapen, J. H.; Scoville, N. Z.; Wilson, C. D.
Bibliographical reference

Active Galactic Nuclei: from Central Engine to Host Galaxy, meeting held in Meudon, France, July 23-27, 2002, Eds.: S. Collin, F. Combes and I. Shlosman. ASP (Astronomical Society of the Pacific), Conference Series, Vol. 290, p. 437.

Advertised on:
0
2003
Number of authors
7
IAC number of authors
0
Citations
0
Refereed citations
0
Description
Through observations and modeling, we demonstrate how the recently discovered large-scale bar in NGC 5248 generates spiral structure that continues from 10 kpc down to 100 pc. Deep inside the bar, two massive CO spirals with streaming motions of 20--40 km/s cover nearly 180 deg in azimuth and connect to two narrow K-band spirals which delineate the super star clusters (SSCs) in a starburst ring at 375 pc. The data suggest that the K-band spirals are young, and the starburst has been triggered by a bar-driven spiral density wave (SDW). The SDW may even have propagated into the inner 90 pc where evidence of recent activity exists. We incorporate the effect of self-gravity in models of bar-driven gaseous SDW and find good agreement between the model and data. Thus study provides some of the best evidence to date for a strong dynamical coupling between the nuclear region and the surrounding disk. It suggests that a low central mass concentration, which may be common in late-type galaxies, is particularly favorable to the propagation of a bar-driven gaseous SDW deep into the central region of the galaxy, whereas a large central mass concentration favors other processes, such as the formation and decoupling of nuclear bars.