A dynamical model for the spiral galaxy NGC 3359

Abstract

In this work we have determined a dynamical model for NGC 3359. This is a strongly barred spiral galaxy with a complex structure, within which we can see an annular zone of intense star formation. In this work we present self consistent numerical simulations of molecular gas in NGC 3359; and using the potential derived from an I band image, we attempt to find the parameters responsible for the kinematics and morphology of the observed gas. The best results are obtained for a two pattern speed model: the central region (up to 15") corresponding to the nuclear bar which rotates with a Ωs=100 km s⁻¹ kpc⁻¹; and the main bar + outer spiral, decoupled from the nuclear region, which rotates with a angular velocity, Ωp = 27 km s⁻¹ kpc⁻¹. The model successfully reproduces the complex structure in H\alpha of the galaxy in the internal 20" zone, which cannot really be explained with a unique mode pattern.