The SAMI Galaxy Survey: gas content and interaction as the drivers of kinematic asymmetry
- Creators
- Bloom, J. V.
- Croom, S. M.
- Bryant, J. J.
- Schaefer, A. L.
- Bland-Hawthorn, J.
- Brough, S.
- Callingham, J.
- Cortese, L.
- Federrath, C.
- Scott, N.
- van de Sande, J.
- D'Eugenio, F.
- Sweet, S.
- Tonini, C.
- Allen, J. T.
- Goodwin, M.
- Green, A. W.
- Konstantopoulos, I. S.
- Lawrence, J.
- Lorente, N.
- Medling, A. M.
- Owers, M. S.
- Richards, S. N.
- Sharp, R.
Abstract
In order to determine the causes of kinematic asymmetry in the Hα gas in the SAMI (Sydney–AAO Multi-object IFS) Galaxy Survey sample, we investigate the comparative influences of environment and intrinsic properties of galaxies on perturbation. We use spatially resolved Hα velocity fields from the SAMI Galaxy Survey to quantify kinematic asymmetry (ν_(asym)) in nearby galaxies and environmental and stellar mass data from the Galaxy And Mass Assembly survey. We find that local environment, measured as distance to nearest neighbour, is inversely correlated with kinematic asymmetry for galaxies with log (M*/M⊙) > 10.0, but there is no significant correlation for galaxies with log (M*/M⊙) < 10.0. Moreover, low-mass galaxies [log (M*/M⊙) < 9.0] have greater kinematic asymmetry at all separations, suggesting a different physical source of asymmetry is important in low-mass galaxies. We propose that secular effects derived from gas fraction and gas mass may be the primary causes of asymmetry in low-mass galaxies. High gas fraction is linked to high σm/V (where σm is Hα velocity dispersion and V the rotation velocity), which is strongly correlated with (ν_(asym)), and galaxies with log (M*/M⊙) < 9.0 have offset σm/V from the rest of the sample. Further, asymmetry as a fraction of dispersion decreases for galaxies with log (M*/M⊙) < 9.0. Gas mass and asymmetry are also inversely correlated in our sample. We propose that low gas masses in dwarf galaxies may lead to asymmetric distribution of gas clouds, leading to increased relative turbulence.
Additional Information
© 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2018 January 12. Received 2018 January 12; in original form 2017 July 9. Published: 01 February 2018. The SAMI Galaxy Survey is based on observations made at the Anglo-Australian Telescope. The Sydney-AAO Multi-object Integral field spectrograph (SAMI) was developed jointly by the University of Sydney and the Australian Astronomical Observatory. The SAMI input catalogue is based on data taken from the SDSS, the GAMA Survey and the VST ATLAS Survey. The SAMI Galaxy Survey is funded by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020, and other participating institutions. The SAMI Galaxy Survey website is http://sami-survey.org/. GAMA is a joint European–Australasian project based around a spectroscopic campaign using the Anglo-Australian Telescope. The GAMA input catalogue is based on data taken from the SDSS and the UKIRT Infrared Deep Sky Survey. Complementary imaging of the GAMA regions is being obtained by a number of independent survey programmes including GALEX MIS, VST KiDS, VISTA VIKING, WISE, Herschel-ATLAS, GMRT ASKAP providing UV to radio coverage. GAMA is funded by the STFC (UK), the ARC (Australia), the AAO, and the participating institutions. The GAMA website is http://www.gama-survey.org/. Support for AMM is provided by NASA through Hubble Fellowship grant HST-HF2-51377 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. SMC acknowledges the support of an Australian Research Council Future Fellowship (FT100100457). MSO acknowledges the funding support from the Australian Research Council through a Future Fellowship (FT140100255). We thank Á. R. López-Sánchez for assisting in the proofreading of the paper.Attached Files
Published - sty273.pdf
Submitted - 1801.06628.pdf
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Additional details
- Eprint ID
- 86320
- Resolver ID
- CaltechAUTHORS:20180509-140937623
- CE110001020
- Australian Research Council
- HST-HF2-51377
- NASA Hubble Fellowship
- NAS5-26555
- NASA
- FT100100457
- Australian Research Council
- FT140100255
- Australian Research Council
- Created
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2018-05-10Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field