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Grand, RJJ, Kawata, D and Cropper, M (2014) Orbits of radial migrators and non-migrators around a spiral arm in N-body simulations. Monthly Notices of the Royal Astronomical Society, 439 (1). pp. 623-638. ISSN 0035-8711
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Orbits of radial migrators and non-migrators around a spiral arm in N-body simulations.pdf - Published Version Download (16MB) | Preview |
Abstract
Recent numerical N-body simulations of spiral galaxies have shown that spiral arms in N-body simulations do not rotate rigidly as expected in classic density wave theory, but instead seem to rotate at a similar speed to the local rotation speed of the stellar disc material. This in turn yields winding, transient and recurrent spiral structure, whose corotating nature gives rise to changes in the angular momentum (radial migration) of star particles close to the spiral arm at many radii. From high-resolution N-body simulations, we highlight the evolution of strongly migrating star particles (migrators) and star particles that do not migrate (non-migrators) around a spiral arm. We investigate the individual orbit histories of migrators and non-migrators and find that there are several types of migrator and non-migrator, each with unique radial evolution. We find the important quantities that affect the orbital evolution to be the radial and tangential velocity components in combination with the azimuthal distance to the spiral arm at the time the star particle begins to feel tangential force. We contrast each type of orbit to compare how these factors combine for migrators and non-migrators. We find that the positive (negative) migrators sustain a position behind (in front of) the spiral arm, and feel continuous tangential force as long as the spiral arm persists. This is because the positive (negative) migrators are close to the apocentre (pericentre) epicycle phase during their migration, and rotate slower (faster) than the corotating spiral arm. On the other hand, non-migrators stay close to the spiral arm, and pass or are passed by the spiral arm one or two times. Although they gain or lose the angular momentum when they are behind or in front of the spiral arm, their net angular momentum change becomes close to zero. We discuss also the long-term effects of radial migration on the radial metallicity distribution and radial angular momentum and mass profiles. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
| Item Type: | Article |
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| Additional Information: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
| Uncontrolled Keywords: | 0201 Astronomical and Space Sciences; Astronomy & Astrophysics |
| Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
| Divisions: | Astrophysics Research Institute |
| Publisher: | Oxford University Press (OUP) |
| SWORD Depositor: | A Symplectic |
| Date Deposited: | 19 Apr 2023 10:07 |
| Last Modified: | 19 Apr 2023 10:18 |
| DOI or ID number: | 10.1093/mnras/stt2483 |
| URI: | https://researchonline.ljmu.ac.uk/id/eprint/19359 |
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