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Bars and Boxy/Peanut-Shaped Bulges: An Observational Point of View

M. Bureau·K. C. Freeman·E. Athanassoula
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Abstract

Prompted by work on the buckling instability in barred spiral galaxies, much effort has been devoted lately to the study of boxy/peanut-shaped (B/PS) bulges. Here, we present new bar diagnostics for edge-on spiral galaxies based on periodic orbits calculations and hydrodynamical simulations. Both approaches provide reliable ways to identify bars and their orientations in edge-on systems. We also present the results of an observational search for bars in a large sample of edge-on spirals with and without B/PS bulges. We show that most B/PS bulges are due to the presence of a thick bar viewed edge-on while only a few may be due to accretion. This strongly supports the bar-buckling mechanism for the formation of B/PS bulges.

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M. Bureau, K. C. Freeman, E. Athanassoula. 1999-01-19. Bars and Boxy/Peanut-Shaped Bulges: An Observational Point of View. https://arxiv.org/abs/astro-ph/9901246

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