The Bar Pattern Speed of NGC 1433 Estimated Via Sticky-Particle Simulations

TL;DR

This paper uses sticky-particle simulations to estimate the pattern speed of the bar in NGC 1433, matching observed morphology with dynamical models to determine its dynamical properties.

Contribution

The study introduces a detailed simulation approach to accurately estimate the bar pattern speed in NGC 1433 using morphological matching.

Findings

Pattern speed of 0.89 km/s/arcsec with 5-10% uncertainty

Ratio of corotation radius to bar radius is 1.7 ± 0.3

Simulation successfully reproduces key morphological features

Abstract

We present detailed numerical simulations of NGC 1433, an intermediate-type barred spiral showing strong morphological features including a secondary bar, nuclear ring, inner ring, outer pseudoring, and two striking, detached spiral arcs known as ``plumes.'' This galaxy is an ideal candidate for recreating the observed morphology through dynamical models and determining the pattern speed. We derived a gravitational potential from an $H$-band image of the galaxy and simulated the behavior of a two-dimensional disk of 100,000 inelastically colliding gas particles. We find that the closest matching morphology between a $B$-band image and a simulation occurs with a pattern speed of 0.89 km s$^{-1}$ arcsec$^{-1}$ $\pm$ 5-10%. We also determine that the ratio of corotation radius to the average published bar radius is 1.7 $\pm$ 0.3, with the ambiguity in the bar radius being the largest contributor to the error.