The evolution of pitch angles of spiral arms

Abstract

In spiral galaxies, the pitch angle, $\alpha$, of the spiral arms is often proposed as a discriminator between theories for the formation of the spiral structure. In Lin-Shu density wave theory, $\alpha$ stays constant in time, being simply a property of the underlying galaxy. In other theories (e.g tidal interaction, self-gravity) it is expected that the arms wind up in time, so that to a first approximation $\cot \alpha \propto t$. For these theories, it would be expected that a sample of galaxies observed at random times should show a uniform distribution of $\cot \alpha$. We show that a recent set of measurements of spiral pitch angles (Yu & Ho 2018) is broadly consistent with this expectation.

arXiv comment4 pages, 3 figures, accepted for publication in MNRAS

References in corpus (22)

• Galaxy Zoo : Morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey
• Dawes Review 4: Spiral Structures in Disc Galaxies
• Self-Perpetuating Spiral Arms in Disk Galaxies
• Simulations of the grand design galaxy M51: a case study for analysing tidally induced spiral structure
• Dynamics of Non-Steady Spiral Arms in Disk Galaxies
• The dynamics of spiral arms in pure stellar disks
• Interplay between Stellar Spirals and the ISM in Galactic Disks
• The Blueshifting and Baldwin effects for the [OIII] 5007 Emission Line in Type 1 Active Galactic Nuclei
• Age distributions of star clusters in spiral and barred galaxies as a test for theories of spiral structure
• Radial Dependence of the Pattern Speed of M51
• Spiral arm pitch angle and galactic shear rate in N-body simulations of disc galaxies
• Galaxy Zoo and SpArcFiRe: Constraints on spiral arm formation mechanisms from spiral arm number and pitch angles
• Bars and spirals in tidal interactions with an ensemble of galaxy mass models
• Search For Star Cluster Age Gradients Across Spiral Arms of Three LEGUS Disk Galaxies
• Pitch angle variations in spiral galaxies
• Dependence of Spiral Arms Pitch Angle on Wavelength as a Test of Density Wave Theory
• Characteristics of Spiral Arms in Late-type Galaxies
• The Carnegie-Irvine Galaxy Survey. VI. Quantifying Spiral Structure
• A direct test of density wave theory in a grand-design spiral galaxy
• The Pattern Speeds of NGC 3031, NGC 2366, and DDO 154 as Functions of Radius
• Investigating the Origins of Spiral Structure in Disk Galaxies through a Multiwavelength Study
• The Shearing HI Spiral Pattern of NGC 1365

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• Spiral instabilities: Mode saturation and decay
• The Effect of Environment on Galaxy Spiral Arms, Bars, Concentration, and Quenching
• Exciting spiral arms in protoplanetary discs from flybys
• How the bar properties affect the induced spiral structure
• Evolution of the spiral structure of galaxies from the HST COSMOS field
• Galaxy And Mass Assembly: Galaxy Zoo spiral arms and star formation rates
• Less Wound and More Asymmetric: JWST Confirms the Evolution of Spiral Structure in Galaxies at $z\lesssim 3$
• Bar-driven Leading Spiral Arms in a Counter-rotating Dark Matter Halo
• The Observed Age Gradient in the Milky Way -- as a Test for theories of spiral arm structure
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