Disk-stability constraints on the number of arms in spiral galaxies

Abstract

A model based on disk-stability criteria to determine the number of spiral arms of a general disk galaxy with an exponential disk, a bulge and a dark halo described by a Hernquist model is presented. The multifold rotational symmetry of the spiral structure can be evaluated analytically once the structural properties of a galaxy, such as the circular speed curve, and the disk surface brightness, are known. By changing the disk mass, these models are aimed at varying the critical length scale parameter of the disk and lead to a different spiral morphology in agreement with prior models. Previous studies based on the swing amplification and disk stability have been applied to constrain the mass-to-light ratio in disk galaxies. This formalism provides an analytic expression to estimate the number of arms expected by swing amplification making its application straight-forward to large surveys. It can be applied to predict the number of arms in the Milky Way as a function of radius and to constrain the mass-to-light ratio in disk galaxies for which photometric and kinematic measurements are available, like in the DiskMass survey. Hence, the halo contribution to the total mass in the inner parts of disk galaxies can be inferred in light of the ongoing and forthcoming surveys.

Accepted for publication to ApJ Letters; 4 pages, 3 figures

References in corpus (1)

• A Fundamental Plane of Spiral Structure in Disk Galaxies

Cited by in corpus (34)

• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• Excitation of coupled stellar motions in the Galactic Disk by orbiting satellites
• Testing Gravity with wide binary stars like $\alpha$ Centauri
• Short-term dynamical evolution of grand-design spirals in barred galaxies
• The dynamics of stellar disks in live dark-matter halos
• The shapes of spiral arms in the S${}^4$G survey and their connection with stellar bars
• Galaxy Zoo and SpArcFiRe: Constraints on spiral arm formation mechanisms from spiral arm number and pitch angles
• Gas and stellar spiral structures in tidally perturbed disc galaxies
• Search For Star Cluster Age Gradients Across Spiral Arms of Three LEGUS Disk Galaxies
• Bars and spirals in tidal interactions with an ensemble of galaxy mass models
• Star formation and ISM morphology in tidally induced spiral structures
• Trojans in the Solar Neighborhood
• Tidally Induced Offset Disks in Magellanic Spiral Galaxies
• The most ancient spiral galaxy: a 2.6-Gyr-old disk with a tranquil velocity field
• How do different spiral arm models impact the ISM and GMC population?
• Migration in the shearing sheet and estimates for young open cluster migration
• Spiral arm formation mechanisms: Spiral Structure in Barred galaxies. Observational constraints to spiral arm formation mechanisms
• The Milky Way's bar structural properties from gravitational waves
• Galaxy Zoo: constraining the origin of spiral arms
• Galactic Spiral Arms by Swing Amplification
• Global Spiral Arms Formation by Non-linear Interaction of Wakelets
• Tidally induced morphology of M33 in hydrodynamical simulations of its recent interaction with M31
• Radial migration and vertical action in N-body simulations
• The Effect of Environment on Galaxy Spiral Arms, Bars, Concentration, and Quenching
• Spirality: A Novel Way to Measure Spiral Arm Pitch Angle
• Modeling of Spiral Structure in a Multi-Component Milky~Way-Like Galaxy
• Bulge formation through disc instability -- I
• Action-based Dynamical Modeling for the Milky Way Disk: The Influence of Spiral Arms
• Global N-Body Simulation of Galactic Spiral Arms
• The origin of the structure of large-scale magnetic fields in disc galaxies
• Effect of finite disk-thickness on swing amplification of non-axisymmetric perturbations in a sheared galactic disk
• Coherent Stellar Motion in Galactic Spiral Arms by Swing Amplification
• Damping of the Milky Way bar by manifold-driven spirals
• Low-mass disc galaxies and the issue of stability: MOND vs dark matter