Radio Galaxy Zoo: host galaxies and radio morphologies for large surveys
  from visual inspection
  We present early results from Radio Galaxy Zoo, a web-based citizen science
project for visual inspection and classification of images from all-sky radio
surveys. The goals of the project are to classify individual radio sources
(particularly galaxies with multiple lobes and/or complex morphologies) as well
as matching the continuum radio emission to the host galaxy. Radio images come
from the FIRST and ATLAS surveys, while matches to potential hosts are
performed with infrared imaging from WISE and SWIRE. The first twelve months of
classification yielded more than 1 million classifications of more than 60,000
sources. For images with at least 75% consensus by the volunteer classifiers,
the accuracy is comparable to visual inspection by the expert science team.
Based on mid-infrared colors, the hosts associated with radio emission are
primarily a mixture of elliptical galaxies, QSOs, and LIRGs, which are in good
agreement with previous studies. The full catalog of radio lobes and their host
galaxies will measure the relative populations of host types as a function of
radio morphology and power. Radio Galaxy Zoo has also been an effective method
for detecting extremely rare objects, such as HyMORs and giant radio galaxies.
Results from the project are being used to train automatic algorithms for host
matching for use in future large continuum surveys such as EMU, as well as
establishing roles for citizen science in projects such as the SKA.
