NGC 1300 Dynamics: II. The response models

TL;DR

This study models the stellar response in NGC 1300 using various potentials and pattern speeds, employing a new quantitative index to match morphological features, and introduces Schwarzschild-type models for improved accuracy.

Contribution

It presents a novel quantitative method for comparing galaxy models with observations and applies Schwarzschild-type techniques to optimize orbital contributions in galaxy modeling.

Findings

Models with pattern speeds around 16 and 22 km/s/kpc best reproduce NGC 1300 features.

The new index effectively quantifies morphological similarities.

Schwarzschild-type models improve the fit to observed galaxy density maps.

Abstract

We study the stellar response in a spectrum of potentials describing the barred spiral galaxy NGC 1300. These potentials have been presented in a previous paper and correspond to three different assumptions as regards the geometry of the galaxy. For each potential we consider a wide range of $\Omega_p$ pattern speed values. Our goal is to discover the geometries and the $\Omega_p$ supporting specific morphological features of NGC 1300. For this purpose we use the method of response models. In order to compare the images of NGC 1300 with the density maps of our models, we define a new index which is a generalization of the Hausdorff distance. This index helps us to find out quantitatively which cases reproduce specific features of NGC 1300 in an objective way. Furthermore, we construct alternative models following a Schwarzschild type technique. By this method we vary the weights of the various energy levels, and thus the orbital contribution of each energy, in order to minimize the differences between the response density and that deduced from the surface density of the galaxy, under certain assumptions. We find that the models corresponding to $\Omega_p\approx16$\ksk and $\Omega_p\approx22$\ksk are able to reproduce efficiently certain morphological features of NGC 1300, with each one having its advantages and drawbacks.