Abstract
The origin of galactic spiral arms is one of the fundamental problems in astrophysics. Based on the local analysis, Toomre (1981) proposed the swing amplification mechanism in which the self-gravity forms spiral arms as leading waves of stars rotate to trailing ones due to galactic shear. The structure of spiral arms is characterized by their number and pitch angle. We perform global N-body simulations of spiral galaxies to investigate the dependence of the spiral structure on disc parameters and compare the simulation results with the swing amplification model. We find that the spiral structure in the N-body simulations agrees well with that predicted by the swing amplification for the wide range of parameters. The pitch angle decreases with increasing the shear rate and is independent of the disc mass fraction. The number of spiral arms decreases with both increasing the shear rate and the disc mass fraction. If the disc mass fraction is fixed, the pitch angle increases with the number of spiral arms.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
