Nearby Galaxies in More Distant Contexts

TL;DR

This paper investigates the evolutionary paths of nearby galaxies using their star formation histories, revealing complex trajectories in galaxy properties over time and highlighting the potential for diverse evolutionary scenarios.

Contribution

It demonstrates how resolved stellar population data can inform understanding of galaxy evolution in a broader extragalactic context, bridging local and distant universe studies.

Findings

Galaxies show complex evolution in the Tully-Fisher relation over time.

Stellar mass growth is weighted towards early times.

Galaxies can traverse the color-magnitude diagram in non-linear paths.

Abstract

We use published reconstructions of the star formation history (SFH) of the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and NGC 300 from the analysis of resolved stellar populations to investigate where such galaxies might land on well-known extragalactic diagnostic plots over the galaxies' lifetime (assuming that nothing other than their stellar populations change). For example, we find that the evolution of these galaxies implies a complex evolution in the Tully-Fisher relation with lookback time and that the observed scatter is consistent with excursions these galaxies take as their stellar populations evolve. We find that the growth of stellar mass is weighted to early times, despite the strongly star-forming current nature of the three systems. Lastly, we find that these galaxies can take circuitous paths across the color-magnitude diagram. For example, it is possible, within the constraints provided by the current determination of its SFH, that the LMC reached the red sequence at intermediate age prior to ending back up on the blue cloud at the current time. Unfortunately, this behavior happens at sufficiently early times that our resolved SFH is crude and insufficiently constraining to convincingly demonstrate that this was the actual evolutionary path. The limited sample size precludes any general conclusions, but we present these as examples how we can bridge the study of resolved populations and the more distant universe.