NIHAO XVIII: Origin of the MOND phenomenology of galactic rotation curves in a LCDM universe

Abstract

The phenomenological basis for Modified Newtonian Dynamics (MOND) is the radial-acceleration-relation (RAR) between the observed acceleration, $a=V_{rot}^2(r)/r$, and the acceleration accounted for by the observed baryons (stars and cold gas), $a_{bar}=V_{bar}^2(r)/r$. We show that the RAR arises naturally in the NIHAO sample of 89 high-resolution LCDM cosmological galaxy formation simulations. The overall scatter from NIHAO is just 0.079 dex, consistent with observational constraints. However, we show that the scatter depends on stellar mass. At high masses ($10^9<M_{star}<10^{11}$ Msun) the simulated scatter is just $\simeq 0.04$ dex, increasing to $\simeq 0.11$ dex at low masses ($10^7<M_{star}<10^9$Msun). Observations show a similar dependence for the intrinsic scatter. At high masses the intrinsic scatter is consistent with the zero scatter assumed by MOND, but at low masses the intrinsic scatter is non-zero, strongly disfavoring MOND. Applying MOND to our simulations yields remarkably good fits to most of the circular velocity profiles. In cases of mild disagreement the stellar mass-to-light ratio and/or "distance" can be tuned to yield acceptable fits, as is often done in observational mass models. In dwarf galaxies with $M_{star}\sim 10^6$Msun MOND breaks down, predicting lower accelerations than observed and in our LCDM simulations. The assumptions that MOND is based on (e.g., asymptotically flat rotation curves, zero intrinsic scatter in the RAR), are approximately, but not exactly, true in LCDM. Thus if one wishes to go beyond Newtonian dynamics there is more freedom in the RAR than assumed by MOND.

arXiv comment15 pages, 15 figures, accepted to MNRAS

References in corpus (36)

• Planck 2013 results. XVI. Cosmological parameters
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Ahf: Amiga's Halo Finder
• Star Formation and Feedback in Smoothed Particle Hydrodynamic Simulations--I. Isolated Galaxies
• Modified Newtonian Dynamics as an Alternative to Dark Matter
• SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves
• The Radial Acceleration Relation in Rotationally Supported Galaxies
• The evolution substructure I: a new identification method
• Making Galaxies in a Cosmological Context: The Need for Early Stellar Feedback
• NIHAO project I: Reproducing the inefficiency of galaxy formation across cosmic time with a large sample of cosmological hydrodynamical simulations
• One Law To Rule Them All: The Radial Acceleration Relation of Galaxies
• The size - virial radius relation of galaxies
• NIHAO IV: Core creation and destruction in dark matter density profiles across cosmic time
• Gasoline2: A Modern SPH Code
• Scaling Relations of Spiral Galaxies
• The Mass Discrepancy-Acceleration Relation: Disk Mass and the Dark Matter Distribution
• Fitting the radial acceleration relation to individual SPARC galaxies
• Weighing Galaxy Disks with the Baryonic Tully-Fisher Relation
• The Mass-Discrepancy Acceleration Relation: a Natural Outcome of Galaxy Formation in Cold Dark Matter halos
• The impact of local stellar radiation on the HI column density distribution
• The mass discrepancy acceleration relation in a $\Lambda$CDM context
• A statistical investigation of the mass discrepancy-acceleration relation
• The origin of the mass discrepancy-acceleration relation in $\Lambda$CDM
• NIHAO XIV: Reproducing the observed diversity of dwarf galaxy rotation curve shapes in LCDM
• Λ CDM is Consistent with SPARC Radial Acceleration Relation
• Absence of a fundamental acceleration scale in galaxies
• NIHAO X: Reconciling the local galaxy velocity function with Cold Dark Matter via mock HI observations
• Semi-Analytical Models for the Formation of Disk Galaxies II. Dark Matter versus Modified Newtonian Dynamics
• NIHAO V: Too big doesn't fail -- reconciling the conflict between LCDM predictions and the circular velocities of nearby field galaxies
• NIHAO XIII: Clumpy discs or clumpy light in high redshift galaxies?
• NIHAO VIII: Circum-galactic medium and outflows - The puzzles of HI and OVI gas distributions
• NIHAO XII: galactic uniformity in a ΛCDM universe
• Dark-Matter Halo Profiles of a General Cusp/Core with Analytic Velocity and Potential
• NIHAO III: The constant disc gas mass conspiracy
• On the radial acceleration relation of $\Lambda$CDM satellite galaxies
• NIHAO XVII: The diversity of dwarf galaxy kinematics and implications for the HI velocity function

Cited by in corpus (29)

• Ultra-Light Dark Matter
• WALLABY -- An SKA Pathfinder HI Survey
• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• Dark Matter Cores and Cusps in Spiral Galaxies and their Explanations
• Predictions and Outcomes for the Dynamics of Rotating Galaxies
• The gravitational field of X-COP galaxy clusters
• NIHAO -- XXV. Convergence in the cusp-core transformation of cold dark matter haloes at high star formation thresholds
• The Intrinsic Scatter of the Radial Acceleration Relation
• The Core-Cusp Problem Revisited: ULDM vs. CDM
• The Scale-Invariant Vacuum (SIV) Theory: A Possible Origin of Dark Matter and Dark Energy
• Scale-Invariant Dynamics of Galaxies, MOND, Dark Matter, and the Dwarf Spheroidals
• On the Presence of a Universal Acceleration Scale in Elliptical Galaxies
• A fundamental test for MOND
• The Effect of Adiabatic Compression on Dark Matter Halos and the Radial Acceleration Relation
• Galaxy rotation curves and universal scaling relations: comparison between phenomenological and fermionic dark matter profiles
• Normalized additional velocity distribution: testing the radial profile of dark matter halos and MOND
• Baryon-Interacting Dark Matter: heating dark matter and the emergence of galaxy scaling relations
• The solar system test for the general modified gravity theories
• Time evolution of the local gravitational parameters and gravitational wave polarizations in a relativistic MOND theory
• A test of Radial Acceleration Relation for the {\it Giles et al Chandra} cluster sample
• ΛCDM with baryons vs. MOND: the time evolution of the universal acceleration scale in the Magneticum simulations
• MIGHTEE-HI: The radial acceleration relation with resolved stellar mass measurements
• Testing the Collisionless Nature of Dark Matter with the Radial Acceleration Relation in Galaxy Clusters
• Dark Coincidences: Small-Scale Solutions with Refracted Gravity and MOND
• The radial acceleration relation at the EDGE of galaxy formation: testing its universality in low-mass dwarf galaxies
• MUSE-DARK III: The evolution of the radial acceleration relation at intermediate redshifts
• On the radial acceleration of disk galaxies
• Disk galaxies and their dark halos as self-organized patterns
• Pattern dark matter and galaxy scaling relations