(\texttt{slick}\): Modeling a Universe of Molecular Line Luminosities in Hydrodynamical Simulations

• Published in: arXiv.org 2024-11
• Main Authors: Garcia, Karolina, Narayanan, Desika, Popping, Gergö, Anirudh, R, Sutherland, Sagan, Kaasinen, Melanie
• Format: Article
• Language: English
• Subjects: Emission analysis; Empirical analysis; Galaxies; Luminosity; Machine learning; Model testing; Physical properties; Radiative transfer; Simulation; Universe
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2311.01508

We present {\sc slick} (the Scalable Line Intensity Computation Kit), a software package that calculates realistic CO, [\ion{C}{1}], and [\ion{C}{2}] luminosities for clouds and galaxies formed in hydrodynamic simulations. Built on the radiative transfer code {\sc despotic}, {\sc slick} computes the thermal, radiative, and statistical equilibrium in concentric zones of model clouds, based on their physical properties and individual environments. We validate our results applying {\sc slick} to the high-resolution run of the {\sc Simba} simulations, testing the derived luminosities against empirical and theoretical/analytic relations. To simulate the line emission from a universe of emitting clouds, we have incorporated random forest machine learning (ML) methods into our approach, allowing us to predict cosmologically evolving properties of CO, [\ion{C}{1}] and [\ion{C}{2}] emission from galaxies such as luminosity functions. We tested this model in 100,000 gas particles, and 2,500 galaxies, reaching an average accuracy of \(\sim\)99.8\% for all lines. Finally, we present the first model light cones created with realistic and ML-predicted CO, [\ion{C}{1}], and [\ion{C}{2}] luminosities in cosmological hydrodynamical simulations, from \(z=0\) to \(z=10\).