Insights from Synthetic Star-forming Regions: I. Reliable Mock Observations from SPH Simulations

TL;DR

This paper develops and evaluates methods for creating realistic synthetic observations from hydrodynamical simulations of star-forming regions, highlighting the importance of accurate radiative transfer setup for reliable property measurements.

Contribution

It introduces optimized techniques for mapping simulation data onto radiative transfer models and provides a comprehensive set of synthetic observations for star formation studies.

Findings

Overestimation of 20 micron flux with naive coupling of dust and gas temperatures

Constant background dust temperature yields more realistic fluxes

Produced 5800 synthetic observations across different bands and conditions

Abstract

Through synthetic observations of a hydrodynamical simulation of an evolving star-forming region, we assess how the choice of observational techniques affects the measurements of properties which trace star formation. Testing and calibrating observational measurements requires synthetic observations which are as realistic as possible. In this part of the paper series (Paper I), we explore different techniques for how to map the distributions of densities and temperatures from the particle-based simulations onto a Voronoi mesh suitable for radiative transfer and consequently explore their accuracy. We further test different ways to set up the radiative transfer in order to produce realistic synthetic observations. We give a detailed description of all methods and ultimately recommend techniques. We have found that the flux around 20 microns is strongly overestimated when blindly coupling the dust radiative transfer temperature with the hydrodynamical gas temperature. We find that when instead assuming a constant background dust temperature in addition to the radiative transfer heating, the recovered flux is consistent with actual observations. We present around 5800 realistic synthetic observations for Spitzer and Herschel bands, at different evolutionary time-steps, distances and orientations. In the upcoming papers of this series (Paper II, Paper III and Paper IV), we will test and calibrate measurements of the star-formation rate (SFR), gas mass and the star-formation efficiency (SFE) using our realistic synthetic observations.