A numerical study of interactions and stellar bars

Abstract

For several decades it has been known that stellar bars in disc galaxies can be triggered by interactions, or by internal processes such as dynamical instabilities. In this work, we explore the differences between these two mechanisms using numerical simulations. We perform two groups of simulations based on isolated galaxies, one group in which a bar develops naturally, and another group in which the bar could not develop in isolation. The rest of the simulations recreate 1:1 coplanar fly-by interactions computed with the impulse approximation. The orbits we use for the interactions represent the fly-bys in groups or clusters of different masses accordingly to the velocity of the encounter. In the analysis we focus on bars' amplitude, size, pattern speed and their rotation parameter, $\mathcal{R}=R_{CR}/R_{bar}$. The latter is used to define fast ($\mathcal{R}<1.4$) and slow rotation ($\mathcal{R}>1.4$). Compared with equivalent isolated galaxies we find that bars affected or triggered by interactions: (i) remain in the slow regime for longer; (ii) are more boxy in face-on views; (iii) they host kinematically hotter discs. Within this set of simulations we do not see strong differences between retrograde or prograde fly-bys. We also show that slow interactions can trigger bar formation.

12 pages, 7 figures. Accepted for publication in MNRAS

References in corpus (13)

• A Near-Infrared Study of 2MASS Bars in Local Galaxies: An Anchor for High Redshift Studies
• The population of barred galaxies in the local universe I. Detection and characterisation of bars
• Properties of Bars and Bulges in the Hubble Sequence
• Image Decomposition of Barred Galaxies and AGN Hosts
• Bars, ovals and lenses in early-type disk galaxies: probes of galaxy evolution
• On the Origin of Dwarf Elliptical Galaxies: The Fundamental Plane
• Disk Evolution and Bar Triggering Driven by Interactions with Dark Matter Substructure
• 2D kinematic signatures of boxy/peanut bulges
• Bar Formation from Galaxy Flybys
• Frequency and properties of bars in cluster and field galaxies at intermediate redshifts
• The environment of barred galaxies in the low-redshift Universe
• The Bar Pattern Speed of NGC 1433 Estimated Via Sticky-Particle Simulations
• The Kinematically Measured Pattern Speeds of NGC 2523 and NGC 4245

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