The SAMI Galaxy Survey

asymmetry in gas kinematics and its links to stellar mass and star formation

J. Bloom, L. M R Fogarty, S. M. Croom, A. L. Schaefer, J. J. Bryant, L. Cortese, S. N. Richards, Joss Bland-Hawthorn, I. T. Ho, N. Scott, Gregory Goldstein, A. M. Medling, Sarah Brough, S. M. Sweet, G. N. Cecil, Angel Lopez Sanchez, K. Glazebrook, Quentin Parker, J. T. Allen, M. Goodwin & 6 others A. W. Green, Iraklis S. Konstantopoulos, J. S. Lawrence, N. P F Lorente, Matt Owers, R. Sharp

Research output: Contribution to journalArticle

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Abstract

We study the properties of kinematically disturbed galaxies in the Sydney-AAO Multi-object Integral field spectrograph (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 ionized gas kinematics, probed by Ha emission. By this method, 23 +/- 7 per cent of our 360-galaxy sub-sample of the SAMI Galaxy Survey are kinematically asymmetric. Visual classifications agree with our kinemetric results for 90 per cent of asymmetric and 95 per cent of normal galaxies. We find that 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 formation 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 0.5R(e)) and outer Ha equivalent widths of asymmetric and normal galaxies shows a small but significant increase in inner equivalent width for asymmetric galaxies.

Original languageEnglish
Pages (from-to)123-148
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Volume465
Issue number1
Early online date12 Oct 2016
DOIs
Publication statusPublished - 11 Feb 2017

Bibliographical note

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Keywords

  • methods: data analysis
  • techniques: imaging spectroscopy
  • galaxies: evolution
  • galaxies: interactions
  • galaxies: kinematics and dynamics
  • galaxies: structure

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Cite this

Bloom, J., Fogarty, L. M. R., Croom, S. M., Schaefer, A. L., Bryant, J. J., Cortese, L., ... Sharp, R. (2017). The SAMI Galaxy Survey: asymmetry in gas kinematics and its links to stellar mass and star formation. Monthly Notices of the Royal Astronomical Society, 465(1), 123-148. https://doi.org/10.1093/mnras/stw2605