Pitch Angle of Galactic Spiral Arms

Abstract

One of the key parameters that characterize spiral arms in disk galaxies is a pitch angle that measures the inclination of a spiral arm to the direction of galactic rotation. The pitch angle differs from galaxy to galaxy, which suggests that the rotation law of galactic disks determines it. In order to investigate the relation between the pitch angle of spiral arms and the shear rate of galactic differential rotation, we perform local $N$-body simulations of pure stellar disks. We find that the pitch angle increases with the epicycle frequency and decreases with the shear rate and obtain the fitting formula. This dependence is explained by the swing amplification mechanism.

arXiv comment17 pages, 8 figures, accepted for publication in ApJ

References in corpus (13)

• Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks
• Self-Perpetuating Spiral Arms in Disk Galaxies
• Dynamics of Non-Steady Spiral Arms in Disk Galaxies
• The dynamics of spiral arms in pure stellar disks
• The Distribution of Bar and Spiral Strengths in Disk Galaxies
• Physical Properties of Tidal Features in Interacting Disk Galaxies
• The origin of large peculiar motions of star-forming regions and spiral structures of our Galaxy
• Constraining dark matter halo profiles and galaxy formation models using spiral arm morphology. I. Method outline
• Spiral arm pitch angle and galactic shear rate in N-body simulations of disc galaxies
• Dust Penetrated Arm Classes: Insights from rising and falling rotation curves
• Density waves in the shearing sheet I. Swing amplification
• Spiral Structure as a Recurrent Instability
• Density waves in the shearing sheet V. Feedback cycle for swing amplification by non-linear effects

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• Galaxy Zoo: Unwinding the Winding Problem - Observations of Spiral Bulge Prominence and Arm Pitch Angles Suggest Local Spiral Galaxies are Winding
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• A Consistent Set of Empirical Scaling Relations for Spiral Galaxies: The $(v_{\max },M_{\mathrm{DM}})$-$({\sigma }_0,M_{\mathrm{BH}},\varphi )$ Relations
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