The mass discrepancy acceleration relation in early-type galaxies:
  extended mass profiles and the phantom menace to MOND
  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 ATLAS$^{3D}$ and SLUGGS data,
which was the first homogenous study of this kind, reaching ~4 $R_e$, 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.
