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Title: 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 morphology, lie on a tight relation linking stellar mass (M {sub *}) to internal velocity quantified by the S {sub 0.5} parameter, which combines the contribution of both dispersion (σ) and rotational velocity (V {sub rot}) to the dynamical support of a galaxy (S{sub 0.5}=√(0.5 V{sub rot}{sup 2}+σ{sup 2})). Our results are independent of the baryonic component from which σ and V {sub rot} are estimated, as the S {sub 0.5} of stars and gas agree remarkably well. This represents a significant improvement compared to the canonical M {sub *} versus V {sub rot} and M {sub *} 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 V {sub rot} and σ are combined. Our findings illustrate how the combination of dispersion and rotational velocities for both gas and starsmore » can provide us with a single dynamical scaling relation valid for galaxies of all morphologies across at least the stellar mass range 8.5 « less
Authors:
; ;  [1] ; ; ; ; ; ; ;  [2] ;  [3] ;  [4] ; ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] more »; « less
  1. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, 3122 Victoria (Australia)
  2. Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia)
  3. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  4. ICRAR, The University of Western Australia, Crawley WA 6009 (Australia)
  5. Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)
  6. Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)
  7. School of Physics, The University of Melbourne, VIC 3010 (Australia)
  8. Astronomy Department, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa)
  9. Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom)
  10. School of Mathematics and Physics, University of Queensland, QLD 4072 (Australia)
Publication Date:
OSTI Identifier:
22364504
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 795; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; BARYONS; COMPARATIVE EVALUATIONS; GALACTIC EVOLUTION; GALAXIES; MASS; MORPHOLOGY; SCALING LAWS; STARS; VELOCITY