Gas and stellar spiral structures in tidally perturbed disc galaxies

• Pettitt, Alex R.

• Tasker, Elizabeth J.

• Wadsley, James W.

抄録

Tidal interactions between disc galaxies and low-mass companions are an established method for generating galactic spiral features. In this work, we present a study of the structure and dynamics of spiral arms driven in interactions between disc galaxies and perturbing companions in 3D N-body/smoothed hydrodynamical numerical simulations. Our specific aims are to characterize any differences between structures formed in the gas and stars from a purely hydrodynamical and gravitational perspective, and to find a limiting case for spiral structure generation. Through analysis of a number of different interacting cases, we find that there is very little difference between arm morphology, pitch angles and pattern speeds between the two media. The main differences are a minor offset between gas and stellar arms, clear spurring features in gaseous arms, and different radial migration of material in the stronger interacting cases. We investigate the minimum mass of a companion required to drive spiral structure in a galactic disc, finding the limiting spiral generation cases with companion masses of the order of 1 x 10(9) M-circle dot, equivalent to only 4 per cent of the stellar disc mass, or 0.5 per cent of the total galactic mass of a Milky Way analogue.

収録刊行物

• Monthly notices of the royal astronomical society

  Monthly notices of the royal astronomical society 458 (4), 3990-4007, 2016-06-02

  Oxford University Press

キーワード

• hydrodynamics
• ISM: structure
• galaxies: interactions
• galaxies: kinematics and dynamics
• galaxies: spiral
• galaxies: structure

詳細情報

• CRID: 1050564288973975680
• NII論文ID: 120005773976
• HANDLE: 2115/62370
• ISSN: 00358711
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles