Handedness asymmetry of spiral galaxies with z<0.3 shows cosmic parity violation and a dipole axis

A dataset of 126,501 spiral galaxies taken from Sloan Digital Sky Survey was used to analyze the large-scale galaxy handedness in different regions of the local universe. The analysis was automated by using a transformation of the galaxy images to their radial intensity plots, which allows automatic analysis of the galaxy spin and can therefore be used to analyze a large galaxy dataset. The results show that the local universe (z<0.3) is not isotropic in terms of galaxy spin, with probability P<∼5.8⋅10−6 of such asymmetry to occur by chance. The handedness asymmetries exhibit an approximate cosine dependence, and the most likely dipole axis was found at RA=132°, DEC=32° with 1σ error range of 107°-179° for the RA. The probability of such axis to occur by chance is P<1.95⋅10−5. The amplitude of the handedness asymmetry reported in this Letter is generally in agreement with Longo, but the statistical significance is improved by a factor of 40, and the direction of the axis disagrees somewhat.