Galaxy Zoo Builder: Four-component Photometric Decomposition of Spiral Galaxies Guided by Citizen Science

Abstract

Multicomponent modeling of galaxies is a valuable tool in the effort to quantitatively understand galaxy evolution, yet the use of the technique is plagued by issues of convergence, model selection, and parameter degeneracies. These issues limit its application over large samples to the simplest models, with complex models being applied only to very small samples. We attempt to resolve this dilemma of “quantity or quality” by developing a novel framework, built inside the Zooniverse citizen-science platform, to enable the crowdsourcing of model creation for Sloan Digital Sky Survey galaxies. We have applied the method, including a final algorithmic optimization step, on a test sample of 198 galaxies, and examine the robustness of this new method. We also compare it to automated fitting pipelines, demonstrating that it is possible to consistently recover accurate models that either show good agreement with, or improve on, prior work. We conclude that citizen science is a promising technique for modeling images of complex galaxies, and release our catalog of models.