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Article
The mass discrepancy acceleration relation in early-type galaxies: extended mass profiles and the phantom menace to MOND
Monthly Notices of the Royal Astronomical Society (2016)
  • Joachim Janz, Swinburne University of Technology
  • Michele Cappellari, University of Oxford
  • Aaron J. Romanowsky, San Jose State University
  • Luca Ciotti, University of Bologna
  • Adebusola B. Alabi, Swinburne University of Technology
  • Duncan A. Forbes, Swinburne University of Technology
Abstract
The dark matter (DM) haloes around spiral galaxies appear to conspire with their baryonic content: empirically, significant amounts of DM are inferred only below a universal characteristic acceleration scale. Moreover, the discrepancy between the baryonic and dynamical mass, which is usually interpreted as the presence of DM, follows a very tight mass discrepancy acceleration (MDA) relation. Its universality, and its tightness in spiral galaxies, poses a challenge for the DM interpretation and was used to argue in favour of MOdified Newtonian Dynamics (MOND). Here, we test whether or not this applies to early-type galaxies. We use the dynamical models of fast-rotator early-type galaxies by Cappellari et al. based on ATLAS3D and SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) data, which was the first homogenous study of this kind, reaching ∼4 Re, where DM begins to dominate the total mass budget. We find the early-type galaxies to follow an MDA relation similar to spiral galaxies, but systematically offset. Also, while the slopes of the mass density profiles inferred from galaxy dynamics show consistency with those expected from their stellar content assuming MOND, some profiles of individual galaxies show discrepancies.
Keywords
  • gravitation,
  • galaxies: elliptical and lenticular,
  • cD,
  • dark matter
Publication Date
September, 2016
DOI
10.1093/mnras/stw1472
Publisher Statement
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.
This article is also available online at the following link: http://dx.doi.org/10.1093/mnras/stw1472
Citation Information
Joachim Janz, Michele Cappellari, Aaron J. Romanowsky, Luca Ciotti, et al.. "The mass discrepancy acceleration relation in early-type galaxies: extended mass profiles and the phantom menace to MOND" Monthly Notices of the Royal Astronomical Society Vol. 461 Iss. 3 (2016) p. 2367 - 2373 ISSN: 1365-2966
Available at: http://works.bepress.com/aaron_romanowsky/95/