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arXiv · 1610.02773

The SAMI Galaxy Survey: Asymmetry in Gas Kinematics and its links to Stellar Mass and Star Formation

J. V. Bloom·L. M. R. Fogarty·S. M. Croom·A. Schaefer·J. J. Bryant·L. Cortese·S. Richards·J. Bland-Hawthorn·I-T. Ho·N. Scott·G. Goldstein·A. Medling·S. Brough·S. M. Sweet·G. Cecil·A. Lopez-Sanchez·K. Glazebrook·Q. Parker·J. T. Allen·M. Goodwin·A. W. Green·I. S. Konstantopoulos·J. S. Lawrence·N. Lorente·M. S. Owers·R. Sharp
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Abstract

We study the properties of kinematically disturbed galaxies in the SAMI Galaxy Survey using a quantitative criterion, based on kinemetry (Krajnovic et al.). The approach, similar to the application of kinemetry by Shapiro et al. uses ionised gas kinematics, probed by H{\alpha} emission. By this method 23+/-7% of our 360-galaxy sub-sample of the SAMI Galaxy Survey are kinematically asymmetric. Visual classifications agree with our kinemetric results for 90% of asymmetric and 95% of normal galaxies. We find stellar mass and kinematic asymmetry are inversely correlated and that kinematic asymmetry is both more frequent and stronger in low-mass galaxies. This builds on previous studies that found high fractions of kinematic asymmetry in low mass galaxies using a variety of different methods. Concentration of star forma- tion and kinematic disturbance are found to be correlated, confirming results found in previous work. This effect is stronger for high mass galaxies (log(M*) > 10) and indicates that kinematic disturbance is linked to centrally concentrated star formation. Comparison of the inner (within 0.5Re) and outer H{\alpha} equivalent widths of asymmetric and normal galaxies shows a small but significant increase in inner equivalent width for asymmetric galaxies.

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J. V. Bloom, L. M. R. Fogarty, S. M. Croom, A. Schaefer, J. J. Bryant, L. Cortese, S. Richards, J. Bland-Hawthorn, I-T. Ho, N. Scott, G. Goldstein, A. Medling, S. Brough, S. M. Sweet, G. Cecil, A. Lopez-Sanchez, K. Glazebrook, Q. Parker, J. T. Allen, M. Goodwin, A. W. Green, I. S. Konstantopoulos, J. S. Lawrence, N. Lorente, M. S. Owers, R. Sharp. 2016-10-10. The SAMI Galaxy Survey: Asymmetry in Gas Kinematics and its links to Stellar Mass and Star Formation. https://doi.org/10.1093/mnras/stw2605

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