Testing Verlinde's emergent gravity in early-type galaxiesTortora, C., Koopmans, L. V. E., Napolitano, N. R. & Valentijn, E. A., Jan-2018, In : Monthly Notices of the Royal Astronomical Society. 473, 2, p. 2324-2334 11 p.
Research output: Contribution to journal › Article › Academic › peer-review
Emergent Gravity (EG) has been proposed to resolve the missing mass problem in galaxies, replacing the potential of dark matter (DM) by the effect of the entropy displacement of dark energy by baryonic matter. This apparent DM depends only on the baryonic mass distribution and the present-day value of the Hubble parameter. In this paper we test the EG proposition, formalized by Verlinde for a spherical and isolated mass distribution using the central dynamics (Sloan Digital Sky Survey velocity dispersion, sigma) and the K-band light distribution in a sample of 4032 massive (M-star greater than or similar to 10(10) M circle dot) and local early-type galaxies (ETGs) from the SPIDER datasample. Our results remain unaltered if we consider the sample of 750 roundest field galaxies. Using these observations we derive the predictions by EG for the stellar mass-to-light ratio (M/L) and the initial mass function (IMF). We demonstrate that, consistently with a classical Newtonian framework with a DM halo component or alternative theories of gravity as MOdified Newtonian Dynamics (MOND), the central dynamics can be fitted if the IMF is assumed non-universal and systematically changing with s. For the case of EG, we find lower, but still acceptable, stellar M/L if compared with the DM-based Navarro, Frenk & White (NFW) model and with MOND, but pretty similar to adiabatically contracted DM haloes and with expectations from spectral gravity-sensitive features. If the strain caused by the entropy displacement would be not maximal, as adopted in the current formulation, then the dynamics of ETGs could be reproduced with larger M/L.
|Number of pages||11|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publication status||Published - Jan-2018|
- galaxies: elliptical and lenticular, cD, galaxies: evolution, galaxies: general, galaxies: structure, dark matter, INITIAL MASS FUNCTION, MODIFIED NEWTONIAN DYNAMICS, CENTRAL DARK-MATTER, TO-LIGHT RATIO, GIANT ELLIPTIC GALAXIES, EQUATION-OF-STATE, DATA RELEASE 7, FUNDAMENTAL PLANE, SCALING RELATIONS, 2-DIMENSIONAL KINEMATICS