We can paint a simple picture of how galaxies form. Dark matter assembles vast structures, drawing gas into their centers by the immense power of gravity. As this gas cools and becomes denser, stars begin to form and a galaxy is born. However, the reality of galaxy formation is complicated by the interaction between gas, stars and black holes, culminating in the slow death of stars via violent supernovae. Predicting exactly how a galaxy will evolve over time is a difficult task!
The EAGLE simulations follow these interactions in a virtual universe, creating thousands of simulated galaxies for us to study. To make sense of the raw numbers that come out of the simulation we can observe these virtual galaxies in the same way we observe real ones. We model their starlight and dust to mimic how they would look to an observer. In doing this we are trying to not only understand how galaxies behave in the EAGLE simulations, but also how we can spot the signs of this behavior in real galaxies.