2020/01/01 by Lior Shamir · 16 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Asymmetry #Cosmology and Gravitation Theories #Dipole #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy group #Gravitation #Radio galaxy #Redshift #Sky #Spin (aerodynamics) #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1017/pasa.2020.46
published in Publications of the Astronomical Society of Australia 37 (Cambridge University Press) · PASA, accepted
openalex publication_date 2020/01/01 · arxiv created 2020/11/15 · openalex created_date 2020/11/23 · arxiv updated 2020/12/16 · openalex updated_date 2026/08/05
Abstract Several recent observations using large data sets of galaxies showed non-random distribution of the spin directions of spiral galaxies, even when the galaxies are too far from each other to have gravitational interaction. Here, a data set of ∼8.7⋅103 spiral galaxies imaged by Hubble Space Telescope ( HST ) is used to test and profile a possible asymmetry between galaxy spin directions. The asymmetry between galaxies with opposite spin directions is compared to the asymmetry of galaxies from the Sloan Digital Sky Survey. The two data sets contain different galaxies at different redshift ranges, and each data set was annotated using a different annotation method. The results show that both data sets show a similar asymmetry in the COSMOS field, which is covered by both telescopes. Fitting the asymmetry of the galaxies to cosine dependence shows a dipole axis with probabilities of ∼2.8σ and ∼7.38σ in HST and SDSS, respectively. The most likely dipole axis identified in the HST galaxies is at (α=78\rm o,δ=47\rm o) and is well within the 1σ error range compared to the location of the most likely dipole axis in the SDSS galaxies with z>0.15 , identified at (α=71\rm o,δ=61\rm o) .