Interpretation of ALMA velocity map for the obscuring torus in NGC1068

TL;DR

This paper models the velocity distribution of clouds in the obscuring torus of NGC1068 using N-body simulations, aligning with recent ALMA observations of a thick, clumpy structure exhibiting orbital motion.

Contribution

It introduces a dynamical N-body model of the torus that accounts for gravitational interactions and reproduces observed velocity patterns.

Findings

Model reproduces ALMA velocity data

Torus exhibits a thick, clumpy structure

Cloud orbits show a spread in inclination and eccentricity

Abstract

Recent ALMA observations have resolved the obscuring torus in the nearest Sy2 galaxy, NGC1068, in the millimeter band. These observations have confirmed the presence of a geometrically thick torus with an orbital motion of its matter and the velocity distribution which can reflect the clumpy structure. In the framework of N-body simulations we consider a dynamical model of an obscuring torus which accounts for the gravitational interaction between the clouds moving in the field of the central mass. In considered model, clouds are orbiting around the central mass exhibiting a spread in inclination and eccentricity. The self-gravity of the torus induces the velocity distribution of clouds with a global orbital motion which mimics the ALMA data for NGC1068.