Finding bars in MaNGA galaxies with Galaxy Zoo: 3D

Mapping Nearby Galaxies at Apache Point Observatory (MaNGA, part of the fourth incarnation of the Sloan Digital Sky Surveys or SDSS-IV), has obtained spatially resolved spectral maps for 10,010 nearby galaxies selected from the SDSS Main Galaxy Sample. Many results from MaNGA have collapsed this structure into azimuthally averaged radial gradients, or symmetric 2D shapes, but there is significantly more information about the effect internal structures have on the evolution of galaxies available if we can identify different internal structures.

One of the simplest ways to identify irregular internal structures in galaxies is by visual inspection. By employing a citizen science technique to ask this question of N independent volunteers we have obtained quantitatively robust masks (and errors) for spirals and bars in MaNGA target galaxies, in a project we call Galaxy Zoo: 3D (Masters et al. 2021). In addition to internal features GZ:3D asked users to identify foreground stars and foreground/background galaxies. 

I review this project, provide a guide on how to make use of the results, hi-light some already published, or in progress projects making use of them, with a particular focus on results related to bars. In particular I show some early results on the excess stellar surface mass density in bars compared to non-bar disc at the same radius.