Synthetic Observations of the HI Line in SPH-Simulated Spiral Galaxies

TL;DR

This paper presents a method to generate synthetic HI spectral-line observations of spiral galaxies from SPH simulations using the radiative transfer code Torus, allowing for flexible viewing angles and observer positions.

Contribution

It introduces a novel approach combining SPH simulations with adaptive mesh refinement and ray-tracing to produce realistic HI observations from any galaxy orientation.

Findings

Generated HI spectral-line cubes for simulated spiral galaxies.

Enabled observation from any viewing angle or observer position.

Simulated HI profiles consistent with observational data.

Abstract

Using the radiative transfer code Torus, we produce spectral-line cubes of the predicted HI profile from global SPH simulations of spiral galaxies. Torus grids the SPH galaxy using Adaptive Mesh Refinement, then applies a ray-tracing method to infer the HI profile along the line(s) of sight. The gridded galaxy can be observed from any direction, which enables us to model the observed HI profile for galaxies of any orientation. We can also place the observer inside the galaxy, to simulate HI observations taken from the Earth's position in the Milky Way.