Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter

Abstract

Assuming virial equilibrium and Newtonian dynamics, low-mass early-type galaxies have larger velocity dispersions than expected from the amount of baryons they contain. The conventional interpretation of this finding is that their dynamics is dominated by non-baryonic matter. However, there is also strong evidence that many low-mass early-type galaxies formed as tidal dwarf galaxies, which would contain almost no dark matter. Using an extensive catalogue of early-type galaxies, we therefore discuss how the internal dynamics of early-type galaxies in general can be understood by replacing the assumption of non-baryonic dark matter with two alternative assumptions. The first assumption is that Milgromian dynamics (i.e., MOND) is valid, which changes the effective gravitational force in the weak-field limit. The second assumption is that binary stars affect the observed line-of-sight velocity dispersions. Some moderate discrepancies between observed and predicted velocity dispersions remain also when these effects are implemented. Nevertheless, the observed velocity dispersions in early-type galaxies can then easily be explained without invoking the presence of non-baryonic dark matter in them, but with already documented variations of the galaxy-wide stellar initial mass function and non-equilibrium dynamics in some of the low-mass early-type galaxies.

arXiv comment18 pages, 6 figures, accepted for publication in MNRAS

References in corpus (113)

• Stellar population synthesis at the resolution of 2003
• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• Dwarf Galaxies of the Local Group
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• The epochs of early-type galaxy formation as a function of environment
• From dwarf spheroidals to cDs: Simulating the galaxy population in a LCDM cosmology
• The Atlas3D project -- I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria
• Modified Newtonian Dynamics (MOND): Observational Phenomenology and Relativistic Extensions
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The Atlas3D project - XV. Benchmark for early-type galaxies scaling relations from 260 dynamical models: mass-to-light ratio, dark matter, Fundamental Plane and Mass Plane
• Modified Newtonian Dynamics as an Alternative to Dark Matter
• Accurate masses for dispersion-supported galaxies
• On the shape of the light profiles of early-type galaxies
• Cuspy No More: How Outflows Affect the Central Dark Matter and Baryon Distribution in Lambda CDM Galaxies
• A systematic variation of the stellar initial mass function in early-type galaxies
• A common mass scale for satellite galaxies of the Milky Way
• A Substantial Population of Low Mass Stars in Luminous Elliptical Galaxies
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• The Observed properties of Dark Matter on small spatial scales
• A Faint New Milky Way Satellite in Bootes
• The Atlas3D project -- IV: the molecular gas content of early-type galaxies
• Forged in FIRE: cusps, cores, and baryons in low-mass dwarf galaxies
• The great disk of Milky-Way satellites and cosmological sub-structures
• The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way
• Modified Newtonian Dynamics in the Milky Way
• The Initial-Final Mass Relation: Direct Constraints at the Low Mass End
• Dwarf Elliptical Galaxies
• A mass-dependent density profile for dark matter haloes including the influence of galaxy formation
• Evidence for top-heavy stellar initial mass functions with increasing density and decreasing metallicity
• A Complete Spectroscopic Survey of the Milky Way Satellite Segue 1: The Darkest Galaxy
• Quasi-linear formulation of MOND
• The stellar and sub-stellar IMF of simple and composite populations
• The dark matter crisis: falsification of the current standard model of cosmology
• Local-Group tests of dark-matter Concordance Cosmology: Towards a new paradigm for structure formation
• Systematic variation of the stellar Initial Mass Function with velocity dispersion in early-type galaxies
• Implications for the formation of star clusters from extra-galactic star-formation rates
• Galaxies as simple dynamical systems: observational data disfavor dark matter and stochastic star formation
• Some Effects of Galaxy Structure and Dynamics on the Fundamental Plane
• Weak homology of elliptical galaxies
• The Star Formation Histories of Local Group Dwarf Galaxies II. Searching For Signatures of Reionization
• Dwarf Galaxy Planes: the discovery of symmetric structures in the Local Group
• MOND and the "Dearth of Dark Matter in Ordinary Elliptical Galaxies"
• Families of dynamically hot stellar systems over ten orders of magnitude in mass
• Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
• The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
• The SPLASH Survey: Spectroscopy of 15 M31 Dwarf Spheroidal Satellite Galaxies
• Missing Mass in Collisional Debris from Galaxies
• From Tidal Dwarf Galaxies to Satellite Galaxies
• Willman 1 - a probable dwarf galaxy with an irregular kinematic distribution
• High-resolution simulations of galaxy mergers: Resolving globular cluster formation
• Do dwarf galaxies form in tidal tails?
• THINGS about MOND
• Local Group Dwarf Spheroidals: Correlated Deviations from the Baryonic Tully-Fisher Relation
• Refining MOND interpolating function and TeVeS Lagrangian
• Strange filamentary structures ("fireballs") around a merger galaxy in the Coma cluster of galaxies
• The vast thin plane of M31 co-rotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group
• Identification of old tidal dwarfs near early-type galaxies from deep imaging and HI observations
• Velocity dispersion around ellipticals in MOND
• X-ray Group and cluster mass profiles in MOND: Unexplained mass on the group scale
• Velocity anti-correlation of diametrically opposed galaxy satellites in the low redshift universe
• A top-down scenario for the formation of massive Tidal Dwarf Galaxies
• Turning the Tides on the Ultra-Faint Dwarf Spheroidal Galaxies: Coma Berenices and Ursa Major II
• Andromeda Dwarfs in Light of MOND. II. Testing Prior Predictions
• The Atlas-3D project - IX. The merger origin of a fast and a slow rotating Early-Type Galaxy revealed with deep optical imaging: first results
• Small scatter and nearly-isothermal mass profiles to four half-light radii from two-dimensional stellar dynamics of early-type galaxies
• The galaxy-wide IMF of dwarf late-type to massive early-type galaxies
• On the nature of the Milky Way satellites
• On the mass-radius relation of hot stellar systems
• Revisiting the influence of unidentified binaries on velocity dispersion measurements in ultra-faint stellar systems
• Dwarf galaxy formation induced by galaxy interactions
• Combined Solar System and rotation curve constraints on MOND
• Dwarf-spheroidal satellites: are they of tidal origin?
• Low-mass X-ray binaries indicate a top-heavy stellar initial mass function in ultra compact dwarf galaxies
• Phantom of RAMSES (POR): A new Milgromian dynamics N-body code
• Reproducing properties of MW dSphs as descendants of DM-free TDGs
• A Search for Point Sources of EeV Neutrons
• Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-Type Galaxies from the SMAKCED Project II. The Survey and a Systematic Analysis of Kinematic Anomalies and Asymmetries
• Can filamentary accretion explain the orbital poles of the Milky Way satellites?
• Leo V: Spectroscopy of a Distant and Disturbed Satellite
• Dynamical population synthesis: Constructing the stellar single and binary contents of galactic field populations
• Does the dwarf galaxy system of the Milky Way originate from Andromeda?
• The dark matter halo of NGC 1399 - CDM or MOND?
• Dwarf elliptical galaxies as ancient tidal dwarf galaxies
• The Influence of Binary Stars on Dwarf Spheroidal Galaxy Kinematics
• The effect of binaries on the dynamical mass determination of star clusters
• Testing MOND Over a Wide Acceleration Range in X-Ray Ellipticals
• RAyMOND: An N-body and hydrodynamics code for MOND
• What is a Galaxy? Cast your vote here...
• Strong Gravitational Lensing and the Stellar IMF of Early-type Galaxies
• Chemo-dynamical evolution of tidal dwarf galaxies. I. Method and IMF dependence
• Dynamics of the NGC 4636 Globular Cluster System - An extremely dark matter dominated galaxy?
• Chemo-dynamical evolution of tidal dwarf galaxies. II. The long-term evolution and influence of a tidal field
• Dwarf spheroidal satellites of the Milky Way from dark matter free tidal dwarf galaxy progenitors: maps of orbits
• Binary populations in Milky Way satellite galaxies: constraints from multi-epoch data in the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
• The early evolution of tidal dwarf galaxies
• Tidal Dwarf Galaxies and missing baryons
• Early-type dwarf galaxies in clusters: a mixed bag with various origins?
• Evidence for a constant IMF in early-type galaxies based on their X-ray binary populations
• Search for Tidal Dwarf Galaxies Candidates in a Sample of Ultraluminous Infrared Galaxies
• Remarks on the properties of elliptical galaxies in modified Newtonian dynamics
• An extensive catalogue of early-type galaxies in the nearby Universe
• A census of the expected properties of classical Milky Way dwarfs in Milgromian dynamics
• MOND and IMF variations in early-type galaxies from $ATLA{S}^{3D}$
• The stretching of Hercules
• Enhanced Mass-to-Light Ratios in UCDs through Tidal Interaction with the Centre of the Host Galaxy
• The mass discrepancy acceleration relation in early-type galaxies: extended mass profiles and the phantom menace to MOND
• A Survey of Proper Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that omega Centauri is Related to the Effect
• H-ATLAS/GAMA: The nature and characteristics of optically red galaxies detected at submillimetre wavelengths
• A Possible Formation Scenario for Dwarf Spheroidal Galaxies I: Fiducial Model
• The number of tidal dwarf satellite galaxies in dependence of bulge index
• A Possible Formation Scenario for Dwarf Spheroidal Galaxies - II: A Parameter Study
• Could Segue 1 be a destroyed star cluster? - a dynamical perspective

Cited by in corpus (17)

• MOND simulation suggests the origin of some peculiarities in the Local Group
• Phenomenological consequences of superfluid dark matter with baryon-phonon coupling
• The binary fraction of stars in dwarf galaxies: the case of Leo II
• Origin of the Local Group satellite planes
• Emergence of the mass discrepancy-acceleration relation from dark matter-baryon interactions
• The effect of tides on the Sculptor dwarf spheroidal galaxy
• 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
• The SAMI -- Fornax Dwarfs Survey II: The Stellar Mass Fundamental Plane and the Dark Matter fraction of Dwarf Galaxies
• How Close Dark Matter Halos and MOND Are to Each Other: Three-Dimensional Tests Based on Gaia DR2
• Mass Discrepancy-Acceleration Relation in Einstein Rings
• Simple interpolation functions for the galaxy-wide stellar initial mass function and its effects in early-type galaxies
• Approaching the Dark Sector through a bounding curvature criterion
• The 800pc long tidal tails of the Hyades star cluster: Possible discovery of candidate epicyclic overdensities from an open star cluster
• MONDian predictions for Newtonian M/L ratios for ultrafaint dSphs
• Are disks of satellites comprised of tidal dwarf galaxies?
• Downsizing revised: Star formation timescales for elliptical galaxies with an environment-dependent IMF and number of SNIa