The Imprint of Spiral Arms on the Galactic Rotation Curve

Abstract

We discuss a model for the Milky Way obtained by fitting the observed terminal velocities with the radial acceleration relation. The resulting stellar surface density profile departs from a smooth exponential disk, having bumps and wiggles that correspond to massive spiral arms. These features are used to estimate the term for the logarithmic density gradient in the Jeans equation, which turn out to have exactly the right location and amplitude to reconcile the apparent discrepancy between the stellar rotation curve and that of the interstellar gas. This model also predicts a gradually declining rotation curve outside the solar circle with slope $-1.7\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{kpc}}^{-1}$, as subsequently observed.

Accepted for publication in the Astrophysical Journal. 16 pages, 4 figures, 4 tables

References in corpus (19)

• The Gaia mission
• The mass distribution and gravitational potential of the Milky Way
• The Radial Velocity Experiment (RAVE): first data release
• The Radial Acceleration Relation in Rotationally Supported Galaxies
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• One Law To Rule Them All: The Radial Acceleration Relation of Galaxies
• Constraining the Milky Way's Hot Gas Halo with OVII and OVII Emission Lines
• Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5
• The mass distribution in early-type disk galaxies: declining rotation curves and correlations with optical properties
• Galaxy And Mass Assembly (GAMA): The galaxy stellar mass function to $z=0.1$ from the r-band selected equatorial regions
• A Tale of Two Paradigms: the Mutual Incommensurability of LCDM and MOND
• Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant
• The Relation between Stellar and Dynamical Surface Densities in the Central Regions of Disk Galaxies
• A statistical investigation of the mass discrepancy-acceleration relation
• Λ CDM is Consistent with SPARC Radial Acceleration Relation
• Constraining the pitch angle of the Galactic spiral arms in the Milky Way
• The Effect of Spiral Structure on the Measurements of the Oort Constants
• Milky Way Kinematics. II. A uniform inner Galaxy HI terminal velocity curve
• Halo Acceleration Relation

Cited by in corpus (19)

• 3D kinematics and age distribution of the Open Cluster population
• Gaia Early Data Release 3: The Galactic anticentre
• Predictions and Outcomes for the Dynamics of Rotating Galaxies
• Gas Dynamics in the Galaxy: Total Mass Distribution and the Bar Pattern Speed
• Gas dynamics in dwarf galaxies as testbeds for dark matter and galaxy evolution
• Mass models of the Milky Way and estimation of its mass from the GAIA DR3 data-set
• Kinematic footprint of the Milky Way spiral arms in Gaia EDR3
• Gravitational orbits in the expanding universe revisited
• Galactic Mass-to-Light Ratios With Superfluid Dark Matter
• Cherenkov radiation from stars constrains hybrid MOND dark matter models
• The imprint of arms and bars on rotation curves: in-plane and off-plane
• Three problems of superfluid dark matter and their solution
• First spiral arm detection using dynamical mass measurements of the Milky Way disk
• A new scale in the quasi-static limit of Aether Scalar Tensor Theory
• Highest-Resolution Rotation Curve of the Inner Milky Way proving the Galactic Shock Wave
• Cosmological implications of the Gaia Milky Way declining rotation curve
• The $\kappa$-model under test of the SPARC database
• The odd primordial halo of the Milky Way implied by Gaia. A shallow core, but a steep decline
• The Baryonic Tully-Fisher Relation in the Local Group and the Equivalent Circular Velocity of Pressure Supported Dwarfs