The Warped Disk of Centaurus A from a radius of 2 to 6500 pc

TL;DR

This study compiles and analyzes the warped structure of Centaurus A's disk from 2 to 6500 parsecs, revealing complex precession patterns and potential influences of self-gravity and gas distribution gaps on disk morphology.

Contribution

It provides a detailed compilation of tilt and inclination angles across a wide radial range, proposing models for the disk's precession and orientation changes, and identifying features related to merger history and gas dynamics.

Findings

Disk orientations form an arc on a polar plot at radii >1 kpc.

Three kinks in disk orientation are identified at ~1.3 kpc, 600 pc, and 100 pc.

Models suggest precession about the jet axis and a decaying orientation toward the center.

Abstract

We compile position and inclination angles for tilted ring fits to the warped dusty and gaseous disk spanning radius 1.8 to 6500 pc from recent observations. For radii exterior to a kpc, tilted ring orientations lie on an arc on a polar inclination versus position angle plot, suggesting that precession following a merger can account for the ring morphology. Three kinks in the ring orientations are seen on the polar plot, the one at radius of about 1.3 kpc we suspect corresponds to the location where self-gravity in the disk affects the ring precession rate. Another at a radius of about 600 pc may be associated with a gap in the gas distribution. A third kink is seen at a radius of 100 pc. A constant inclination tilted disk precessing about the jet axis may describe the disk between 100 and 20 pc but not interior to this. A model with disk orientation matching the molecular circumnuclear disk at 100 pc that decays at smaller radii to an inner flat disk perpendicular to the jet may account for disk orientations within 100 pc. Neither model would account for the cusps or changes in disk orientation at 100 or 600 pc.