The Galaxy Zoo project has provided quantitative visual morphologies for over a million galaxies, and has been part of a reinvigoration of interest in the morphologies of galaxies and what they reveal about galaxy evolution. Morphological information collected by GZ has shown itself to be a powerful tool for studying galaxy evolution, and GZ continues to collect classifications - currently serving imaging from DECaLS in its main site, and running a variety of related projects hosted by the Zooniverse; the citizen science platform which came out of the early success of GZ. I highlight some of the results from the last twelve years, with a particular emphasis on linking morphology and dynamics, look forward to future projects in the GZ family, and provide a quick start guide for how you can easily make use of citizen science techniques to analysis your own large and complex data sets.

The star formation history (SFH) of galaxies is a principle uncertainty in SED modeling, and simple parameterizations of the SFH in typical SED fitting techniques may introduce biases in the resulting derived parameters. It is possible to constrain the SFH of galaxies more tightly through the observations of resolved stellar colour-magnitude diagrams with HST. This work is a first attempt to combine constraints on galaxy SFH from resolved stars with broadband SED modeling from the UV to the IR. This combination allows for the effects of different realistic SFHs on the SED to be quantified.

Blind HI surveys provide a census of galaxies in the local universe that is unbiased by their optical properties. Even the Arecibo Dual-Beam Survey with a sample of only 265 galaxies discovered many low surface brightness galaxies and one galaxy with no obvious stellar component. Overall the galaxies in this survey display a diverse range of gas-to-stellar properties. The environment in which a galaxy resides is shown to be one of the factors responsible for this diversity, but it is not the only one. Clearly there are other factors affecting the complex processes responsible for the conversion of gas into stars rapidly in some galaxies, slowly in others, and rapidly in the center while slowly in the outskirts in still other galaxies. Nevertheless, even the inefficient star formation observed in a large fraction of the gas-rich galaxies appears to be a significant contributor to the overall star-formation rate density locally and therefore an important driver of galaxy evolution that must be understood. We focus on a discussion of the stellar and star formation properties in a 21 cm selected sample of galaxies because it is these measurements that contain the most information about the nature of star formation in galaxies.

Galaxy bimodality is caused by the bulge-disc nature of galaxies as opposed to two distinct galaxy classes. This is evident in the colour-structure plane which clearly shows that elliptical galaxies (bulge-only) lie in the red compact peak and late-type spiral galaxies (disc-dominated) lie in the blue diffuse peak. Early-type spirals (bulge plus disc systems) sprawl across both peaks. However after bulge-disc decomposition the bulges of early-type spirals lie exclusively in the red compact peak and their discs in the blue diffuse peak (exceptions exist but are rare, e.g., dust reddened edge-on discs and blue pseudo-bulges). Movement between these two peaks is not trivial because whilst switching off star-formation can transform colours from blue to red, modifying the orbits of ~1 billion stars from a planar diffuse structure to a triaxial compact structure is problematic (essentially requiring an equal mass merger). We propose that the most plausible explanation for the dual structure of galaxies is that galaxy formation proceeds in two stages. First an initial collapse phase (forming a centrally concentrated core and black hole), followed by splashback, infall and accretion (forming a planar rotating disc). Dwarf systems coule perhaps follow the same scenario but the lack of low luminosity bulge-disc systems would imply that the two components must rapidly blend to form a single flattened spheroidal system.

I will discuss the connection between the luminosity function of a population of high-mass X-ray binaries in a galaxy and the star formation rate in the this galaxy. The understanding of this connection provides on the one hand an independent measure of an important galaxy property, and on the other hand new insights into populations of high-mass X-ray binaries. In particular, observations with the Chandra X-ray telescope are uniquely suited to investigate the X-ray part of this connection and I will present examples of this.