Trident: a universal tool for generating synthetic absorption spectra from astrophysical simulations

Abstract

Hydrodynamical simulations are increasingly able to accurately model physical systems on stellar, galactic, and cosmological scales, however, the utility of these simulations is often limited by our ability to directly compare them with the datasets produced by observers: spectra, photometry, etc. To address this problem, we have created Trident}, a Python-based, open-source tool for post-processing hydrodynamical simulations to produce synthetic absorption spectra and related data. Trident} can (i) create absorption-line spectra for any trajectory through a simulated dataset mimicking both background quasar and down-the-barrel configurations, (ii) reproduce the spectral characteristics of common instruments like the Cosmic Origins Spectrograph, (iii) operate across the ultraviolet, optical and infrared using customizable absorption line lists, (iv) trace simulated physical structures directly to spectral features, (v) approximate the presence of ion species absent from the simulation outputs, (vi) generate column density maps for any ion, and (vii) provide support for all major astrophysical hydrodynamical codes. The focus of Trident's development is for using simulated datasets to better interpret observations of the circumgalactic medium (CGM) and intergalactic medium (IGM), but it remains a general tool applicable in other contexts.