2007/08/03 by Silvia Toonen, Toonen, Silvia, Kambiz Fathi +7
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.0708.0504
To appear in the conference proceedings for "Pathways Through an Eclectic Universe", Editors: Johan H. Knapen, Terry J. Mahoney, and Alejandro Vazdekis
arxiv created 2008/01/18 · arxiv updated 2009/12/01
We study the kinematics of the barred spiral galaxy NGC 6946 by investigating the velocity field from H-alpha Fabry-Perot observations, determined 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/s/kpc. 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.