# A 1D fluid model of the Centaurus A jet

## TL;DR

This paper develops a one-dimensional steady flow model for the Centaurus A jet, constrained by X-ray observations, to estimate flow properties and the effects of stellar mass loss entrainment on jet dynamics.

## Contribution

It introduces a realistic, constrained 1D fluid model for the Centaurus A jet that incorporates stellar mass loss and observational data to estimate jet velocities and flow characteristics.

## Key findings

- Jet velocity decreases modestly from ~0.67c to ~0.52c along the jet.
- Entrainment of stellar mass loss significantly influences jet momentum flux.
- Flow Mach number varies between ~5.3 and 3.6 along the jet.

## Abstract

We implement a steady, one-dimensional flow model for the X-ray jet of Centaurus A in which entrainment of stellar mass loss is the primary cause of dissipation. Using over 260 ks of new and archival Chandra/ACIS data, we have constrained the temperature, density and pressure distributions of gas in the central regions of the host galaxy of Centaurus A, and so the pressure throughout the length of its jet. The model is constrained by the observed profiles of pressure and jet width, and conserves matter and energy, enabling us to estimate jet velocities, and hence all the other flow properties. Invoking realistic stellar populations within the jet, we find that the increase in its momentum flux exceeds the net pressure force on the jet unless only about one half of the total stellar mass loss is entrained. For self-consistent models, the bulk speed only falls modestly, from ~0.67c to ~0.52c over the range of 0.25-5.94 kpc from the nucleus. The sonic Mach number varies between ~5.3 and 3.6 over this range.