The Pattern Speeds of NGC 6946

Toonen, S.; Fathi, K.; Falcón-Barroso, J.; Beckman, J. E.; de Zeeuw, P. T.
Bibliographical reference

Pathways Through an Eclectic Universe ASP Conference Series, Vol. 390, proceedings of the conference held 23-27 April, 2007 at Santiago del Teide, Tenerife, Spain. Edited by J. H. Knapen, T. J. Mahoney, and A. Vazdekis San Francisco: Astronomical Society of the Pacific, 2008., p.322

Advertised on:
6
2008
Number of authors
5
IAC number of authors
0
Citations
1
Refereed citations
1
Description
We study the kinematics of the barred spiral galaxy NGC 6946 by investigating the velocity field from Hα Fabry-Perot observations, determine the pattern speed of the bar by using the Tremaine-Weinberg method, and find a main pattern speed of 21.7+4.0-0.8 km-1 s-1 kpc-1. Our data clearly suggest the presence of an additional pattern with a pattern speed more than twice that of the large pattern in this galaxy. We use the epicycle approximation to deduce the location of the resonance radii and subsequently determine the pattern speed between the radii, and find that inside the inner inner Lindblad resonance radius a bar-like system has evolved.