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arXiv · 2410.08277

The Impact of Classical Bulges on Stellar Bars and Box-Peanut-X-Features in Disk Galaxies

Rachel Lee McClure·Angus Beane·Elena D'Onghia·Carrie Filion·Kathryne J. Daniel
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Abstract

Galactic bars and their associated resonances play a significant role in shaping galaxy evolution. Resulting resonance-driven structures, like the vertically extended Boxy/Peanut X-Feature (BPX), then serve as a useful probe of the host galaxy's history. In this study, we quantify the impact of a classical bulge on the evolution of the bar and the growth of bar resonance structures. This is accomplished with a suite of isolated N-body disk galaxy simulations with bulge mass fractions ranging from 0% to 16% of the disk mass. We apply frequency analysis to the stellar orbits to analyze the variations in resonance structure evolution. Our findings indicate that a more massive initial bulge leads to the formation of a stronger and more extended bar and that each bar drives the formation of a prominent associated BPX through resonance passage. In this work, we present evidence that the formation of a BPX is driven by planar, bar-supporting orbits evolving through interaction with horizontal and vertical bar-resonances. More orbits become vertically extended when these resonances intersect, and the rate of the orbits passing through resonance is moderated by the overall fraction of vertically extended orbits. A significant bulge stabilizes the fraction of vertically extended orbits, preventing sudden resonance-induced changes. Crucially, neither sudden resonance intersection nor prolonged resonance trapping is required for BPX formation.

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Rachel Lee McClure, Angus Beane, Elena D'Onghia, Carrie Filion, Kathryne J. Daniel. 2024-10-10. The Impact of Classical Bulges on Stellar Bars and Box-Peanut-X-Features in Disk Galaxies. https://doi.org/10.1093/mnras%2Fstaf107

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