Karen Masters, Coleman Krawczyk, Chris Lintott, Robert Simpson
We present a new interface under development in collaboration with the Zooniverse. Through this website, citizen scientists will be able to help to create photometric decompositions of galaxy images. Currently, Galaxy Zoo crowdsourced classifications (e.g. Lintott et al. 2011, Willett et al. 2014, 2016, Simmons et al. 2016) provide reliable answers to questions about morphological features present in galaxies, and large catalogues of (unsupervised) automated photometric decompositions also exist (e.g. Simard et al. 2011). This interface combines the best of both techniques: allowing crowdsourcing of the many tasks in model fitting which need human input, while leveraging computer optimization techniques for the final numeric results. In the prototype interface, volunteers select which components are needed to fit a galaxy light profile (e.g. bulge(s), disc, bar, spirals) and input rough isophotes for these various components. This process can be viewed as placing a starting point for the best model fit near a global minimum, after which computer algorithms for nonlinear fitting will find the nearest minimum for the functional parameters provided (i.e. sersic index, maximum intensity). Volunteers can then adjust the model if the best fit appears non-physical. This interface will run as a project on the Zooniverse system, and the intended output is a catalogue of guided photometric decompositions for a large sample of galaxies.