2020/07/31 by Steve K. Choi, Matthew Hasselfield, Shuay-Pwu Patty Ho +137 · 2 citations
Physics and Astronomy · #Anisotropy #Cosmic background radiation #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Planck #Polarization (electrochemistry) #Radio Astronomy Observations and Technology #South Pole Telescope #Spectral density #Spectral line #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2020/12/045
44 pages, 27 figures, products available on the NASA LAMBDA website, version accepted for publication in JCAP
openalex created_date 2020/07/23 · arxiv created 2020/11/23 · openalex publication_date 2020/12/01 · arxiv updated 2021/11/18 · openalex updated_date 2026/08/06
We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg 2 of the 2013–2016 survey, which covers >15000 deg 2 at 98 and 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related to this, show numerous checks for systematic error done before unblinding. Using the likelihood for the cosmological analysis we constrain secondary sources of anisotropy and foreground emission, and derive a “CMB-only” spectrum that extends to ℓ=4000. At large angular scales, foreground emission at 150 GHz is ∼1% of TT and EE within our selected regions and consistent with that found by Planck . Using the same likelihood, we obtain the cosmological parameters for ΛCDM for the ACT data alone with a prior on the optical depth of τ=0.065±0.015. ΛCDM is a good fit. The best-fit model has a reduced χ 2 of 1.07 (PTE=0.07) with H 0 =67.9±1.5 km/s/Mpc. We show that the lensing BB signal is consistent with ΛCDM and limit the celestial EB polarization angle to ψ P =−0.07 ̂ ±0.09 ̂ . We directly cross correlate ACT with Planck and observe generally good agreement but with some discrepancies in TE. All data on which this analysis is based will be publicly released.