Stellar Dynamical Modeling - Accuracy of 3D Density Estimation for Edge-on Axisymmetric Galaxies

TL;DR

This study evaluates the accuracy of two stellar dynamical modeling methods in reconstructing the 3D light distribution of edge-on axisymmetric galaxies, revealing limitations and differences in their performance.

Contribution

It provides a comparative analysis of made-to-measure and Schwarzschild's methods using simulated galaxies, highlighting their inaccuracies in 3D density estimation.

Findings

Made-to-measure method yields more accurate 3D density estimates than Schwarzschild's method.

Both methods generally fail to accurately recover the true 3D distributions.

Results impact the interpretation of other luminosity-weighted galaxy properties.

Abstract

From Rybicki's analysis using the Fourier slice theorem, mathematically it is possible to reproduce uniquely an edge-on axisymmetric galaxy's 3D light distribution from its 2D surface brightness. Utilizing galaxies from a cosmological simulation, we examine the ability of Syer and Tremaine's made-to-measure method and Schwarzschild's method for stellar dynamical modeling to do so for edge-on oblate axisymmetric galaxies. Overall, we find that the methods do not accurately recover the 3D distributions, with the made-to-measure method producing more accurate estimates than Schwarzschild's method. Our results have implications broader than just luminosity density, and affect other luminosity-weighted distributions within galaxies, for example, age and metallicity.