The truncation of stellar discs: the magnetic hypothesis

Abstract

We propose a hypothesis of the truncation of stellar discs based on the magnetic model of the rotation curve of spiral galaxies. Once the disc had formed and acquired its present structure, approximately, three balanced forces were acting on the initial gas: gravity and magnetic forces, inwards, and centrifugal force. When stars are formed from this gas, the magnetic force is suddenly suppressed. Gravitation alone cannot retain the newly-formed stars and at birth places beyond a certain galactocentric radius they escape to intergalactic space. This radius is the so-called ``truncation radius'', which is predicted to be at about 4-5 disc radial scale lengths, in promising agreement with observations.

6 pages, accepted for publication in Astronomy and Astrophysics Replaced using new A&A style

References in corpus (3)

• Star Formation Thresholds in Galactic Disks
• Statistics of galaxy warps in the HDF North and South
• Near infrared observations of the truncation of stellar disks

Cited by in corpus (11)

• The Outer Disks of Early-Type Galaxies. I. Surface-Brightness Profiles of Barred Galaxies
• Color Profiles of Spiral Galaxies: Clues on Outer-Disk Formation Scenarios
• The Structure of the Outer Galactic Disc as revealed by IPHAS early A Stars
• No direct coupling between bending of galaxy disc stellar age and light profiles
• The gravitational force and potential of the finite Mestel disk
• Are rotation curves in NGC 6946 and the Milky Way magnetically supported?
• Constraining the Magnetic Effects on HI Rotation Curves and the Need for Dark Halos
• The puzzle about the radial cut-off in galactic disks
• Flares, Warps, Truncations, and Satellite: The Ultra-thin Galaxy UGC 11859
• Truncated stellar discs in the near infrared. II. Statistical properties and interpretation
• Galaxy rotation curves: the effect of j x B force