2022/12/02 by Heliana E. Luparello, Heliana E Luparello, Ezequiel F. Boero +7 · 20 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #CMB cold spot #Cosmic microwave background #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Intergalactic travel #Physics #Planck #Redshift
paper · open access · doi:10.1093/mnras/stac3491
published in Monthly Notices of the Royal Astronomical Society 518(4), 5643-5652 (Oxford University Press)
openalex publication_date 2022/12/02 · openalex created_date 2022/12/25 · openalex updated_date 2026/08/05
ABSTRACT We report and analyse a serendipitous finding of foregrounds in the cosmic microwave background (CMB) radiation associated with extended galactic haloes. Using the cross-correlation of Planck and Wilkinson Microwave Anisotropy Probe maps and the 2MRS galaxy catalogue, we find that the mean temperature radial profiles around nearby galaxies at cz≤ 4500~\rm km~s-1 show a statistically significant systematic decrease of ∼ 15~μ \rm K extending up to several galaxy radii. This deficit in the temperature strongly depends on the galaxy morphological type at scales within several tens of times the galaxy size, becoming nearly independent of galaxy morphology at larger scales. The effect is significantly stronger for the more extended galaxies, with galaxy clustering having a large impact on the results. Our findings indicate the presence of statistically relevant foregrounds in the CMB maps that should be considered in detailed cosmological studies. Besides, we argue that these can be used to explore the intergalactic medium surrounding bright late-type galaxies and allow for diverse astrophysical analyses.