The pattern speed of the bar in NGC 4596 |
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| Authors: | Joris Gerssen Konrad Kuijken Michael R Merrifield |
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| Institution: | Kapteyn Institute, Groningen 9700 AV, The Netherlands; Department of Physics &Astronomy, University of Southampton, SO17 1BJ |
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| Abstract: | The pattern speed is a defining parameter of any barred galaxy. A large number of model-dependent techniques have therefore been developed to derive the pattern speed. However, the only model-independent technique for measuring this quantity – the Tremaine–Weinberg method – has hitherto been applied to just one case, the SB0 galaxy NGC 936. In this paper, we apply the technique to a second system, the SBa galaxy NGC 4596. The resulting estimate for the pattern speed is Ωp=52±13 km s−1 kpc−1. This result is corroborated by a spectrum obtained along the major axis of the bar in this system. The corotation radius associated with this pattern speed lies just beyond the end of the bar indicating a fast bar. Combining the bar major-axis spectra with data obtained from a Hubble Space Telescope WFPC2 image, we also find strong evidence for a nuclear disc. |
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| Keywords: | galaxies: fundamental parameters galaxies: individual: NGC 4596 galaxies: kinematics and dynamics galaxies: nuclei |
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