Hydrodynamic simulations for the nuclear morphology of NGC 4314

We performed smoothed particle hydrodynamic (SPH) simulations to study the nuclear morphology of the barred galaxy NGC 4314. We have constructed the mass models based on the results of a profile decomposition into disk, bulge, and bar components. Our models have three different nuclear structures according to the assumption about the nuclear bar: no nuclear bar, a synchronous nuclear bar, and a fast nuclear bar. Our SPH simulations show that the morphology of the nuclear region of NGC 4314, which is characterized by an elongated ring and/or spiral of newly formed stars and H II regions, aligned nearly parallel to the primary bar, can be understood in terms of the secular evolution driven by the nonaxisymmetric potential. The slightly elongated and aligned nuclear ring of NGC 4314 can be formed by the strong barred potential and the moderate central concentration of the bulge mass, with and without a nuclear bar. However, the nuclear spiral pattern cannot be developed without a nuclear bar. The nuclear bar of NGC 4314 seems to rotate faster than the primary bar, since the nuclear morphology induced by the synchronous nuclear bar is much different from the observed one.