Through the Gaussian Blur: Using Realistic Simulations to Test the Relationship Between Galaxy Physical Properties and Observed Emission

Extragalactic astronomers design and take observations of distant galaxies and from these draw conclusions about their physical conditions. But how accurate are these conclusions? In this project, we tested how well the properties of galaxies can be inferred from observations. We used simulations of galaxies from the FIRE-2 suite, where the ”ground truth’ is known. Running radiative transfer on the simulations, we made predictions for observable galaxy images at different wavelengths, from different viewing angles. We then compared these observable images to projected maps of physical properties such as stellar, dust and gas mass and star formation rate, on a pixel-by-pixel basis. We confirmed that maps of longer wavelength light reflect the projected distribution of gas and dust mass, while shorter wavelengths map the stellar mass and star formation rate.