# Numerical simulation of surface brightness of astrophysical jets

## TL;DR

This paper presents a method for simulating the surface brightness of astrophysical jets by combining gas dynamical simulations with spectral synthesis, validated against Hubble observations of HH 30.

## Contribution

It introduces a general post-processing procedure using Cloudy for simulating jet brightness, validated with observational and magnetohydrodynamic data.

## Key findings

- Simulated brightness matches Hubble observations well.
- The approach accurately reproduces trends in forbidden line emissions.
- Validation confirms the method's effectiveness for astrophysical jet studies.

## Abstract

We outline a general procedure for simulating the surface brightness of astrophysical jets (and other astronomical objects) by post-processing gas dynamical simulations of densities and temperatures using spectral line emission data from the astrophysical spectral synthesis package {\em Cloudy}. Then we validate the procedure by comparing the simulated surface brightness of the HH~30 astrophysical jet in the forbidden [O~I], [N~II], and [S~II] doublets with {\em Hubble Space Telescope}\/ observations of Hartigan and Morse and multiple-ion magnetohydrodynamic simulations of Tesileanu et al. The general trend of our simulated surface brightness in each doublet using the gas dynamical/{\em Cloudy}\/ approach is in excellent agreement with the observational data.