The intricate link between galaxy dynamics and intrinsic shape (or why so-called prolate rotation is a misnomer)

Many recent integral integral field spectroscopy (IFS) survey teams have used stellar kinematic maps combined with imaging to statistically infer the underlying distributions of galaxy intrinsic shapes. With now several IFS samples at our disposal, the method, which was originally proposed by M. Fra...

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Bibliographic Details
Main Authors: Foster, Caroline, Bassett, Robert
Format: Article in Journal/Newspaper
Language:unknown
Published: arXiv 2019
Subjects:
Online Access:https://dx.doi.org/10.48550/arxiv.1908.08648
https://arxiv.org/abs/1908.08648
Description
Summary:Many recent integral integral field spectroscopy (IFS) survey teams have used stellar kinematic maps combined with imaging to statistically infer the underlying distributions of galaxy intrinsic shapes. With now several IFS samples at our disposal, the method, which was originally proposed by M. Franx and collaborators in 1991, is gaining in popularity, having been so far applied to ATLAS3D, SAMI, MANGA and MASSIVE. We present results showing that a commonly assumed relationship between dynamical and intrinsic shape alignment does not hold in Illustris, affecting our ability to recover accurate intrinsic shape distributions. A further implication is that so-called "prolate rotation", where the bulk of stars in prolate galaxies are thought to rotate around the projected major axis, is a misnomer. : 4 pages, 1 figure, IAU353 Proceedings