THE SAMI GALAXY SURVEY: TOWARD A UNIFIED DYNAMICAL SCALING RELATION FOR GALAXIES OF ALL TYPES
We take advantage of the first data from the Sydney-AAO Multi-object Integral field Galaxy Survey to investigate the relation between the kinematics of gas and stars, and stellar mass in a comprehensive sample of nearby galaxies. We find that all 235 objects in our sample, regardless of their morpho...
Published in: | The Astrophysical Journal |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Astronomical Society
2014
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Subjects: | |
Online Access: | http://hdl.handle.net/1959.3/388853 https://doi.org/10.1088/2041-8205/795/2/L37 |
Summary: | We take advantage of the first data from the Sydney-AAO Multi-object Integral field Galaxy Survey to investigate the relation between the kinematics of gas and stars, and stellar mass in a comprehensive sample of nearby galaxies. We find that all 235 objects in our sample, regardless of their morphology, lie on a tight relation linking stellar mass (M∗) to internal velocity quantified by the S0.5 parameter, which combines the contribution of both dispersion (σ) and rotational velocity (Vrot) to the dynamical support of a galaxy (S0.5 = √ 0.5 Vrot2 + σ2). Our results are independent of the baryonic component from which σ and V rot are estimated, as the S 0.5 of stars and gas agree remarkably well. This represents a significant improvement compared to the canonical M∗ versus Vrot and M∗ versus σ relations. Not only is no sample pruning necessary, but also stellar and gas kinematics can be used simultaneously, as the effect of asymmetric drift is taken into account once Vrot and σ are combined. Our findings illustrate how the combination of dispersion and rotational velocities for both gas and stars can provide us with a single dynamical scaling relation valid for galaxies of all morphologies across at least the stellar mass range 8.5 |
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