open access

https://hdl.handle.net/2115/62370

Gas and stellar spiral structures in tidally perturbed disc galaxies

英語

galaxies: structure

2016-06-02

Oxford University Press

Monthly notices of the royal astronomical society

458(4)

3990-4007

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.

学術雑誌論文

Version of Record

This article has been accepted for publication in Monthly notices of the royal astronomical society ©:2016 doi: 10.1093/mnras/stw588 Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved.

0035-8711