First Radio Galaxy Zoo paper has been accepted!

The first Radio Galaxy Zoo paper has been accepted by the Monthly Notices of the Royal Astronomical Society (MNRAS) and is available today on astro-ph.  The paper entitled “Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection” outlines the project and provides the first look into some of the science that has come from Radio Galaxy Zoo.

Fig. 1. An example of a galaxy where visual identification of the radio components is necessary. the automated algorithms would have classified the non-core emission as independent sources, whereas RGZ volunteers (in agreement with the science team) find all five radio emission components in the upper half of the image to be related to the same source.

As mentioned in our previous article about the paper, we find that the RGZ citizen scientists are as effective as the RGZ science team in identifying the radio sources and the host galaxies.  The project now has over 7500 citizen scientists and their contributions are individually acknowledged at http://rgzauthors.galaxyzoo.org

Fig. 2. (a) WISE colour-colour diagram showing approximately 100,000 WISE all-sky sources (colourmap), 4614 RGZ sources (black contours), and powerful radio galaxies (green points). (b) WISE colour-colour diagram showing the locations of various classes of astrophysical objects from Wright et al. (2010).

Using the classifications of the WISE infrared host galaxies, we find that the majority of the host galaxies are located in the WISE colour space consisting of elliptical galaxies, quasi-stellar objects (QSOs), and luminous infrared radio galaxies (LIRGs) – see Fig. 2.  Upon closer examination of the RGZ objects that are identified as elliptical galaxies in the WISE W1-W2< 0.5 colour space we note that our current sample shows a possible large population of star-forming galaxies and/or ellipticals with enhanced dust – see Fig. 3.

Fig. 3. Distribution of (W2 – W3) infrared colours for objects near the region identified as elliptical galaxies (W1 – W2) < 0.5. Solid and dashed vertical lines show the median colours of the all-sky and RGZ sources. While sources randomly selected from the WISE all-sky sample peak near (W2 – W3) = 0, our current RGZ sample shows a large population with significantly redder colours – possibly from star-forming galaxies and/or ellipticals with enhanced dust.

We still have a lot of radio sources in our project that need classification and we hope to continue the great work from all our citizen scientists and science team.  Don’t forget to head over to Radio Talk for interesting discussions on objects or some of the science in general.
Thank you once again for your hard work and support throughout the first years of Radio Galaxy Zoo!