Hydrodynamical Simulations of the Barred Spiral Galaxy NGC 1097

TL;DR

This study uses two-dimensional hydrodynamical simulations to replicate the gas morphology and kinematics of NGC 1097, revealing the influence of a strong bar and gas self-gravity on its structure and starburst activity.

Contribution

It introduces detailed hydrodynamical models that incorporate gas self-gravity to explain the observed features of NGC 1097, including the starburst ring and gas inflow rates.

Findings

Gas morphology and kinematics are reproduced by a strong, slowly rotating bar potential.

The starburst ring is gravitationally unstable due to gas self-gravity.

Gas inflow rate into the starburst region is approximately 0.17 solar masses per year.

Abstract

NGC 1097 is a nearby barred spiral galaxy believed to be interacting with the elliptical galaxy NGC 1097A located to its northwest. It hosts a Seyfert 1 nucleus surrounded by a circumnuclear starburst ring. Two straight dust lanes connected to the ring extend almost continuously out to the bar. The other ends of the dust lanes attach to two main spiral arms. To provide a physical understanding of its structural and kinematical properties, two-dimensional hydrodynamical simulations have been carried out. Numerical calculations reveal that many features of the gas morphology and kinematics can be reproduced provided that the gas flow is governed by a gravitational potential associated with a slowly rotating strong bar. By including the self-gravity of the gas disk in our calculation, we have found the starburst ring to be gravitationally unstable which is consistent with the observation in \citet{hsieh11}. Our simulations show that the gas inflow rate is 0.17 M$_\sun$ yr$^{-1}$ into the region within the starburst ring even after its formation, leading to the coexistence of both a nuclear ring and a circumnuclear disk.