The Cusp/Core Problem in Galactic Halos: Long-Slit Spectra for a Large Dwarf Galaxy Sample

Abstract

We derive inner dark matter halo density profiles for a sample of 165 low-mass galaxies using rotation curves obtained from high-quality, long-slit optical spectra assuming minimal disks and spherical symmetry. For $\rho (r)\sim r^{-\alpha }$ near the galaxy center we measure median inner slopes ranging from ${\alpha }_m=0.22\pm 0.08$ to $0.28\pm 0.06$ for various subsamples of the data. This is similar to values found by other authors, and in stark contrast to the intrinsic cusps (${\alpha }_{int}\sim 1$) predicted by simulations of halo assembly in cold dark matter (CDM) cosmologies. To elucidate the relationship between ${\alpha }_m$ and ${\alpha }_{int}$ in our data, we simulate long-slit observations of model galaxies with halo shapes broadly consistent with the CDM paradigm. Simulations with ${\alpha }_{int}=1/2$ and 1 recover both the observed distribution of ${\alpha }_m$ and correlations between ${\alpha }_m$ and primary observational parameters such as distance and disk inclination, whereas those with ${\alpha }_{int}=5/4$ are marginally consistent with the data. Conversely, the hypothesis that low-mass galaxies have ${\alpha }_{int}=3/2$ is rejected. While the simulations do not imply that the data favor intrinsic cusps over cores, they demonstrate that the discrepancy between ${\alpha }_m$ and ${\alpha }_{int}\sim 1$ for our sample does not necessarily imply a genuine conflict between our results and CDM predictions: rather, the apparent cusp/core problem may be reconciled by considering the impact of observing and data processing techniques on rotation curves derived from long-slit spectra.

17 pages, 14 figures; uses emulateapj. Accepted for publication in AJ. Minor changes made to match AJ proofs

References in corpus (37)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Stellar mass-to-light ratios and the Tully-Fisher relation
• The Dependence of Star Formation History and Internal Structure on Stellar Mass for 10^5 Low-Redshift Galaxies
• Concentrations of Dark Halos from their Assembly Histories
• The Inner Structure of LambdaCDM Halos III: Universality and Asymptotic Slopes
• The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
• Response of dark matter halos to condensation of baryons: cosmological simulations and improved adiabatic contraction model
• H alpha rotation curves of Low Surface Brightness galaxies
• The cored distribution of dark matter in spiral galaxies
• Mass Density Profiles of LSB Galaxies
• The Central Mass Distribution in Dwarf and Low Surface Brightness Galaxies
• Properties of galaxy dark matter halos from weak lensing
• The Phase-Space Density Profiles of Cold Dark Matter Halos
• The Dark Matter Distribution in the Central Regions of Galaxy Clusters: Implications for CDM
• The Dark Matter Distribution in the Central Regions of Galaxy Clusters
• High-resolution rotation curves of low surface brightness galaxies: Data
• Simulating Observations of Dark Matter Dominated Galaxies: Towards the Optimal Halo Profile
• Evolution of the Mass Function of Dark Matter Haloes
• Flat-Cored Dark Matter in Cuspy Clusters of Galaxies
• The Formation of Dust Lanes: Implications for Galaxy Evolution
• Cuspy Dark-Matter Haloes and the Galaxy
• The Angular Momentum Content of Dwarf Galaxies: New Challenges for the Theory of Galaxy Formation
• Halpha rotation curves: the soft core question
• The Inner Structure of LCDM Halos II: Halo Mass Profiles and LSB Rotation Curves
• Dependence of the Inner DM Profile on the Halo Mass
• The rotation curves of dwarf galaxies: a problem for Cold Dark Matter?
• Physical Sources of Scatter in the Tully-Fisher Relation
• Galaxy formation in pre-processed dark halos
• Mass Modeling of Disk Galaxies: Constraints, Degeneracies and Adiabatic Contraction
• The visible matter - dark matter coupling
• XMM-Newton observation of the relaxed cluster A478: gas and dark matter distribution from 0.01 R_200 to 0.5 R_200
• A Limit on the Cosmological Mass Density and Power Spectrum from the Rotation Curves of Low Surface Brightness Galaxies
• Accurate determination of the mass distribution in spiral galaxies III. Fabry-Perot imaging spectroscopy of 6 spiral galaxies
• The Inner Scale Length of Spiral Galaxy Rotation Curves
• A Redshift Survey of Nearby Galaxy Groups: the Shape of the Mass Density Profile
• M/L, H-alpha Rotation Curves, and HI Measurements for 329 Nearby Cluster and Field Spirals: I. Data
• Cosmological constraints from the masses and abundances of L* galaxies

Cited by in corpus (118)

• The Core-Cusp Problem
• Concentration, Spin and Shape of Dark Matter Haloes: Scatter and the Dependence on Mass and Environment
• Can dark matter be a Bose-Einstein condensate?
• High-resolution mass models of dwarf galaxies from LITTLE THINGS
• The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations
• The distribution of dark matter in galaxies
• Galaxy Masses
• The central slope of dark matter cores in dwarf galaxies: Simulations vs. THINGS
• Small scale problems of the $\Lambda$CDM model: a short review
• The rotation curves shapes of late-type dwarf galaxies
• Modeling Non-Circular Motions in Disk Galaxies: Application to NGC 2976
• Empirical Models for Dark Matter Halos. II. Inner profile slopes, dynamical profiles, and rho/sigma^3
• The velocity width function of galaxies from the 40% ALFALFA survey: shedding light on the cold dark matter overabundance problem
• Dark Matter from Early Decays
• A dark matter profile to model diverse feedback-induced core sizes of $\Lambda$CDM haloes
• Haloes of k-Essence
• High Resolution Optical Velocity Fields of 11 Low Surface Brightness Galaxies
• Is there Evidence for Flat Cores in the Halos of Dwarf Galaxies?: The Case of NGC 3109 and NGC 6822
• Spreading out and staying sharp - Creating diverse rotation curves via baryonic and self-interaction effects
• Density profile of dark matter haloes and galaxies in the Horizon-AGN simulation: the impact of AGN feedback
• Core creation in galaxies and haloes via sinking massive objects
• Non-circular motions and the diversity of dwarf galaxy rotation curves
• Stellar kinematics and metallicities in the Leo I dwarf spheroidal galaxy -- wide field implications for galactic evolution
• The Dynamical and Chemical Evolution of Dwarf Spheroidal Galaxies
• Stellar kinematics in the remote Leo II dwarf spheroidal galaxy -- Another brick in the wall
• The Cusp/Core problem and the Secondary Infall Model
• Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics
• Template Rotation Curves for Disk Galaxies
• An extensive study of dynamical friction in dwarf galaxies: the role of stars, dark matter, halo profiles and MOND
• Dynamical Friction around Supermassive Black Holes
• A Testable Conspiracy: Simulating Baryonic Effects on Self-Interacting Dark Matter Halos
• The Rotation Velocity Attributable to Dark Matter at Intermediate Radii in Disk Galaxies
• Dark matters on the scale of galaxies
• The Dynamical and Chemical Evolution of Dwarf Spheroidal Galaxies with GEAR
• Hiding Cusps in Cores: Kinematics of Disk Galaxies in Triaxial Dark Matter Halos
• Hidden Sector Hydrogen as Dark Matter: Small-scale Structure Formation Predictions and the Importance of Hyperfine Interactions
• Some aspects of generalized modified gravity models
• Dipolar Dark Matter and Dark Energy
• Collisionally Regenerated Dark Matter Structures in Galactic Nuclei
• Resolution of dark matter problem in f(T) gravity
• Constraining the NFW Potential with Observations and Modeling of LSB Galaxy Velocity Fields
• Velocity Dependence from Resonant Self-Interacting Dark Matter
• Pressure Support in Galaxy Disks: Impact on Rotation Curves and Dark Matter Density Profiles
• Density profiles of dark matter haloes on Galactic and Cluster scales
• Density profile slope in Dwarfs and environment
• On the Density profile slope of Clusters of Galaxies
• Cosmology: small scale issues revisited
• The Core-Cusp Problem in Cold Dark Matter Halos and Supernova Feedback: Effects of Oscillation
• Self-interacting inelastic dark matter: A viable solution to the small scale structure problems
• On the universality of density profiles
• Rotation curve fitting and its fatal attraction to cores in realistically simulated galaxy observations
• In-spiraling Clumps in Blue Compact Dwarf Galaxies
• An accurate measurement of the baryonic Tully-Fisher relation with heavily gas-dominated ALFALFA galaxies
• Computational issues in chemo-dynamical modelling of the formation and evolution of galaxies
• Dissipational versus Dissipationless Galaxy Formation and the Dark Matter Content of Galaxies
• The core-cusp problem in cold dark matter halos and supernova feedback: Effects of Mass Loss
• A Deficit of Dark Matter from Jeans Modeling of the Ultra-diffuse Galaxy NGC 1052-DF2
• Cusp-to-core transition in low-mass dwarf galaxies induced by dynamical heating of cold dark matter by primordial black holes
• The bar pattern speed of NGC 4431
• Self-interacting dark matter without prejudice
• Microlensing of an extended source by a power-law mass distribution
• RC100: Rotation Curves of 100 Massive Star-Forming Galaxies at z=0.6-2.5 Reveal Little Dark Matter on Galactic Scales
• A cuspy dark matter halo
• SHIELD: Neutral Gas Kinematics and Dynamics
• Observations Supporting the Existence of an Intrinsic Magnetic Moment Inside the Central Compact Object Within the Quasar Q0957+561
• The dark matter halos of the bluest low surface brightness galaxies
• The Structure of Rapidly Rotating Late-Type Spiral Galaxies: I. Photometry, HI and Optical Kinematics
• Non-circular motions and the cusp-core discrepancy in dwarf galaxies
• Constraints on interacting dark energy models from galaxy Rotation Curves
• Mirror Matter, Mirror Gravity and Galactic Rotational Curves
• Toward Understanding the origin of the Fundamental Plane for Early-Type Galaxies
• Simulations of galactic disks including a dark baryonic component
• Relations between abundance characteristics and rotation velocity for star-forming MaNGA galaxies
• Statistical properties of the dark matter haloes of dwarf galaxies and correlations with the environment
• The Mutual Interaction Between Population III Stars and Self-Annihilating Dark Matter
• Formation of Dark Matter Torii Around Supermassive Black Holes Via The Eccentric Kozai-Lidov Mechanism
• Fornax globular cluster distributions: implications for the cusp-core problem
• The connection between the cusp-to-core transformation and observational universalities of DM halos
• Re-examining the Too-Big-To-Fail Problem for Dark Matter Haloes with Central Density Cores
• The SAMI Galaxy Survey: The Low-Redshift Stellar Mass Tully-Fisher Relation
• Embedding globular clusters in dark matter minihalos solves the cusp-core and timing problems in the Fornax dwarf galaxy
• Dark Matter Density Profiles in Dwarf Galaxies: Linking Jeans Modeling Systematics and Observation
• Effect of dark matter annihilation on gas cooling and star formation
• The cusp-core problem in gas-poor dwarf spheroidal galaxies
• Global radiation signature from early structure formation
• The mass distribution in Spirals
• The SLUGGS Survey: The Inner Dark Matter Density Slope of the Massive Elliptical Galaxy NGC 1407
• Navarro-Frenk-White dark matter profile and the dark halos around disk systems
• A detailed statistical analysis of the mass profiles of galaxy clusters
• The diversity of spiral galaxies explained
• Density Profiles of Collisionless Equilibria. II. Anisotropic Spherical Systems
• Dynamical Models for NGC 6503 using a Markov Chain Monte Carlo Technique
• Testing baryon-induced core formation in $\Lambda$CDM: A comparison of the DC14 and coreNFW dark matter halo models on galaxy rotation curves
• Effect of Population III Multiplicity on Dark Star Formation
• Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves
• Uncovering dark matter density profiles in dwarf galaxies with graph neural networks
• Solving the Cusp-Core Problem with a Novel Scalar Field Dark Matter
• A self-consistent hydrostatic mass modelling of pressure supported dwarf galaxy Leo T
• A spherical scalar-tensor galaxy model
• Self-gravitating equilibrium models of dwarf galaxies and the minimum mass for star formation
• Core-Cusp revisited and Dark Matter Phase Transition Constrained at O(0.1) eV with LSB Rotation Curve
• Galactic phase transition at Ec=0.11 eV from rotation curves of cored LSB galaxies and nonperturbative dark matter mass
• Transonic solutions of isothermal galactic winds in a cold dark matter halo
• Characterising bars in low surface brightness galaxies
• The proper motion of stars in dwarf galaxies: distinguishing central density cusps from cores
• Condensation of Galactic Cold Dark Matter
• Strong lensing by subhalos in the dwarf-galaxy mass range I: Image separations
• Trial by FIRE: Probing the dark matter density profile of dwarf galaxies with GraphNPE
• Central densities of dark matter halos in FIRE-2 simulations of low-mass galaxies with cold dark matter and self-interacting dark matter
• Low surface brightness galaxies mass profiles as a consequence of galactic evolution
• Constraining Dwarf Spheroidal Dark Matter Halos With The Galactic Center Excess
• The star pile in Abell 545
• Dynamical disequilibrium in dwarf galaxies: rethinking gas dynamics, rotation curves, and dark matter inference
• Dipolar Dark Matter and Cosmology
• Dark matter as a condensate: Deduction of microscopic properties
• Constraints on dark and visible mass in galaxies from strong gravitational lensing
• Dark Matter Universal Properties in Galaxies
• Does the gamma-ray signal from the central Milky Way indicate Sommerfeld enhancement of dark matter annihilation?