Radial migration in numerical simulations of Milky Way-sized galaxies

Abstract

We show that in N-body simulations of isolated spiral discs, spiral arms appear to transient, recurring features that co-rotate with the stellar disc stars at all radii. As a consequence, stars around the spiral arm continually feel a tangential force from the spiral and gain/lose angular momentum at all radii where spiral structure exists, without gaining significant amounts of random energy. We demonstrate that the ubiquitous radial migration in these simulations can be seen as outward (inward) systematic streaming motions along the trailing (leading) side of the spiral arms. We characterise these spiral induced peculiar motions and compare with those of the Milky Way obtained from APOGEE red clump data. We find that transient, co-rotating spiral arms are consistent with the data, in contrast with density wave-like spirals which are qualitatively inconsistent. In addition, we show that, in our simulations, radial migration does not change the radial metallicity gradient significantly, and broadens the metallicity distribution function at all radii.

4 pages, 3 figures. To appear in Astronomische Nachrichten, special issue "Reconstructing the Milky Way's History: Spectroscopic surveys, Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J. Montalbán, and M. Steffen, AN 2016 (in press)"

References in corpus (5)

• The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk
• Impact of radial migration on stellar and gas radial metallicity distribution
• Gas and Stellar Motions and Observational Signatures of Co-Rotating Spiral Arms
• Spiral and bar driven peculiar velocities in Milky Way sized galaxy simulations
• The stellar kinematics of co-rotating spiral arms in Gaia mock observations

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• The evolution of the Milky Way: New insights from open clusters
• Constraining churning and blurring in the Milky Way using large spectroscopic surveys -- an exploratory study
• Open Clusters as Tracers on Radial Migration of the Galactic Disk
• A Dynamical Model for Clustered Star Formation in the Galactic Disk
• Characterizing the radial oxygen abundance distribution in disk galaxies
• Age-metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia
• Empirical derivation of the metallicity evolution with time and radius using TNG50 Milky Way/Andromeda analogues
• Improved SED-Fitting Assumptions Result in Inside-Out Quenching at $z\sim 0.5$ and Quenching at All Radii Simultaneously at $z\sim 1$
• The Spiral Pattern Speed in the Milky Way Galaxy