Observationally-Motivated Analysis of Simulated Galaxies

TL;DR

This paper demonstrates that applying observational selection functions to simulated galaxies yields insights comparable to real data analysis, emphasizing the importance of methodology in interpreting galaxy simulations.

Contribution

It introduces an observationally-motivated analysis method for simulated galaxies, highlighting its impact compared to traditional spatial cut approaches.

Findings

Selection functions significantly influence the interpretation of simulated galaxy data.

Observationally-motivated analysis aligns simulation results more closely with real observations.

Methodology choice can be as impactful as underlying physics in simulation analysis.

Abstract

The spatial and temporal relationships between stellar age, kinematics, and chemistry are a fundamental tool for uncovering the physics driving galaxy formation and evolution. Observationally, these trends are derived using carefully selected samples isolated via the application of appropriate magnitude, colour, and gravity selection functions of individual stars; conversely, the analysis of chemodynamical simulations of galaxies has traditionally been restricted to the age, metallicity, and kinematics of `composite' stellar particles comprised of open cluster-mass simple stellar populations. As we enter the Gaia era, it is crucial that this approach changes, with simulations confronting data in a manner which better mimics the methodology employed by observers. Here, we use the \textsc{SynCMD} synthetic stellar populations tool to analyse the metallicity distribution function of a Milky Way-like simulated galaxy, employing an apparent magnitude plus gravity selection function similar to that employed by the RAdial Velocity Experiment (RAVE); we compare such an observationally-motivated approach with that traditionally adopted - i.e., spatial cuts alone - in order to illustrate the point that how one analyses a simulation can be, in some cases, just as important as the underlying sub-grid physics employed.