MOND and IMF variations in early-type galaxies from $ATLA{S}^{3D}$

Abstract

MOdified Newtonian dynamics (MOND) represents a phenomenological alternative to dark matter (DM) for the missing mass problem in galaxies and clusters of galaxies. We analyze the central regions of a local sample of $\sim 220$ early-type galaxies from the $\mathrm{ATLA}{\mathrm{S}}^{3D}$ survey, to see if the data can be reproduced without recourse to DM. We estimate dynamical masses in the MOND context through Jeans analysis, and compare to $\mathrm{ATLA}{\mathrm{S}}^{3D}$ stellar masses from stellar population synthesis. We find that the observed stellar mass--velocity dispersion relation is steeper than expected assuming MOND with a fixed stellar initial mass function (IMF) and a standard value for the acceleration parameter $a_0$. Turning from the space of observables to model space, a) fixing the IMF, a universal value for $a_0$ cannot be fitted, while, b) fixing $a_0$ and leaving the IMF free to vary, we find that it is "lighter" (Chabrier-like) for low-dispersion galaxies, and "heavier" (Salpeter-like) for high dispersions. This MOND-based trend matches inferences from Newtonian dynamics with DM, and from detailed analysis of spectral absorption lines, adding to the converging lines of evidence for a systematically-varying IMF.

6 pages, 3 figures, accepted for publication on MNRAS Letters, typos corrected and further references added

References in corpus (6)

• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• A systematic variation of the stellar initial mass function in early-type galaxies
• Revealing the properties of dark matter in the merging cluster MACSJ0025.4-1222
• The PN.S Elliptical Galaxy Survey: the dark matter in NGC 4494
• Dwarf Spheroidals in MOND
• The Optical Colors of Giant Elliptical Galaxies and their Metal-Rich Globular Clusters Indicate a Bottom-Heavy Initial Mass Function

Cited by in corpus (26)

• Variations of the stellar initial mass function in the progenitors of massive early-type galaxies and in extreme starburst environments
• The stellar initial mass function of early type galaxies from low to high stellar velocity dispersion: homogeneous analysis of ATLAS${}^{3D}$ and Sloan Lens ACS galaxies
• Evolution of galaxy size--stellar mass relation from the Kilo Degree Survey
• Systematic variations of central mass density slopes in early-type galaxies
• Galaxy properties as revealed by MaNGA. I. Constraints on Initial Mass Function and M${}_{\ast }$/L gradients in ellipticals
• Evolution of central dark matter of early-type galaxies up to z ~ 0.8
• $M_{\ast }/L$ gradients driven by IMF variation: Large impact on dynamical stellar mass estimates
• The last 6 Gyr of dark matter assembly in massive galaxies from the Kilo Degree Survey
• Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter
• The SLUGGS Survey: Multi-population dynamical modelling of the elliptical galaxy NGC 1407 from stars and globular clusters
• On the Presence of a Universal Acceleration Scale in Elliptical Galaxies
• The mass discrepancy acceleration relation in early-type galaxies: extended mass profiles and the phantom menace to MOND
• Testing Verlinde's emergent gravity in early-type galaxies
• A universal velocity dispersion profile for pressure supported systems: evidence for MONDian gravity across 7 orders of magnitude in mass
• Study of gravitational fields and globular cluster systems of early-type galaxies
• Dark Matter and IMF normalization in Virgo dwarf early-type galaxies
• Central velocity dispersion catalog of LAMOST-DR7 galaxies
• Dynamics of Elliptical Galaxies with Planetary Nebulae in Modified Newtonian Dynamics
• A Test of MONDian Gravity in $\sim$300 pressure supported elliptical galaxies from the MaNGA survey
• Origin of the fundamental plane of elliptical galaxies in the Coma Cluster without fine-tuning
• VIMOS mosaic integral-field spectroscopy of the bulge and disk of the early-type galaxy NGC 4697
• Triaxial Schwarzschild Models of NGC 708: a 10-billion solar mass black hole in a low dispersion galaxy with a Kroupa IMF
• Simple interpolation functions for the galaxy-wide stellar initial mass function and its effects in early-type galaxies
• The central dark matter fraction of massive early-type galaxies
• Comparing IMF-sensitive indices of intermediate-mass quiescent galaxies in various environments
• CASCO: Cosmological and AStrophysical parameters from Cosmological simulations and Observations -- II. Constraining cosmology and astrophysical processes with early- and late-type galaxies