The Atacama Cosmology Telescope: Weighing Distant Clusters with the Most Ancient Light

Abstract

We present cosmological constraints from a gravitational lensing mass map covering 9400 deg 2 reconstructed from measurements of the cosmic microwave background (CMB) made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with measurements of baryon acoustic oscillations (BAO, from SDSS and 6dF), we obtain the amplitude of matter fluctuations σ 8 = 0.819 ± 0.015 at 1.8% precision, S 8 ≡ σ 8 (Ω m /0.3) 0.5 = 0.840 ± 0.028 and the Hubble constant H 0 = (68.3 ± 1.1) km s −1 Mpc −1 at 1.6% precision. A joint constraint with CMB lensing measured by the Planck satellite yields even more precise values: σ 8 = 0.812 ± 0.013, S 8 ≡ σ 8 (Ω m /0.3) 0.5 = 0.831 ± 0.023 and H 0 = (68.1 ± 1.0) km s −1 Mpc −1 . These measurements are in excellent agreement with ΛCDM-model extrapolations from the CMB anisotropies measured by Planck. To compare these ACT CMB lensing constraints to those from the KiDS, DES, and HSC galaxy surveys, we revisit those data sets with a uniform set of assumptions, and find S 8 from all three surveys are lower than that from ACT+Planck lensing by varying levels ranging from 1.7-2.1σ. These results motivate further measurements and comparison, not just between the CMB anisotropies and galaxy lensing, but also between CMB lensing probing z ∼ 0.5 − 5 on mostly-linear scales and galaxy lensing at z ∼ 0.5 on smaller scales. We combine our CMB lensing measurements with CMB anisotropy data to constrain extensions of ΛCDM, limiting the sum of the neutrino masses to m ν < 0.12 eV (95% c.l.), for example. We also provide constraints independent of the CMB anisotropy data from Planck, using instead WMAP and ACT CMB data to constrain the spatial curvature density to −0.017 < Ω k < 0.012 (95% c.l.) and the dark energy density to Ω Λ = 0.68±0.01. We describe the mass map and related data products that will enable a wide array of cross-correlation science. This map is signal-dominated for lensing mass map multipoles L < 150 with the large scales measured with a signal-to-noise ratio around twice that of Planck. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the ΛCDM model, while paving a promising path for neutrino physics with gravitational lensing from upcoming ground-based CMB surveys. 5 https://github.com/carronj/planck PR4 lensing 0.750 0.775 0.800 0.825 0.850 0.875 8 ACT lensing: baseline ACT lensing: inpaint SZ ACT lensing: polarization only ACT lensing: CIB deproj. ACT lensing: linear theory Planck CMB aniso.

Atacama Cosmology Telescope measurements of a large sample of candidates from the Massive and Distant Clusters of WISE Survey

“…In this work we use data from ACT DR5 to establish how SZ mass scales with the MaDCoWS definition of richness for a large sample of MaDCoWS cluster candidates. The work presented here complements the recent work by Madhavacheril et al (2020), who report the mean mass, determined through stacked CMB lensing, of the MaDCoWS candidates located within the ACT survey region and above a richness of 20 (Sect. 2.1).…”

“…In red are the masses or ỹ0 values computed per richness bin. For comparison, we include, as a yellow diamond, the average mass estimate computed by Madhavacheril et al (2020) from CMB lensing, shown at the mean value of λ 15 used in that work. We note that the left and center plots do not show the negative ỹ0 points, but those points are included in all fits shown.…”

Strong detection of the CMB lensing and galaxy weak lensing cross-correlation from ACT-DR4,PlanckLegacy, and KiDS-1000

“…Planck lensing is expected to have negligible foreground biases due to the lower resolution of Planck. Darwish et al (2021) presented CMB lensing convergence maps reconstructed from ACT data applying two methodsthe first using only ACT data and the second using internal linear combinations (ILC) of Planck and ACT data to remove contamination from the tSZ effect (Madhavacheril & Hill 2018;Madhavacheril et al 2020). We performed our analysis on both sets of maps to confirm that this did not impact our results.…”

“…These not only improve cosmological model constraints, but also help test various astrophysical and instrumental systematic effects which can limit our analyses and potentially cause tensions between parameters. For example, cross-correlating CMB lensing with populations of galaxies (for example Smith et al 2007;Hirata et al 2008;Bleem et al 2012;Allison et al 2015;Bianchini et al 2015;Giannantonio et al 2016;Peacock & Bilicki 2018;Omori et al 2019a;Krolewski et al 2020;Darwish et al 2021), quasars (Sherwin et al 2012;Geach et al 2013), galaxy groups (Madhavacheril et al 2015), and clusters (Baxter et al 2018;Madhavacheril et al 2020) can be used to measure the bias of these foreground tracers as well as the growth factor. Crosscorrelating CMB lensing with the cosmic infrared background (CIB, Holder et al 2013;Planck Collaboration XVIII 2014;van Engelen et al 2015;Lenz et al 2019), or correlating galaxy or CMB lensing with the thermal Sunyaev-Zel'dovich effect (Van Waerbeke et al 2014;Hill & Spergel 2014;Hojjati et al 2017) informs us about the relationship between dark matter and baryons.…”

The Atacama Cosmology Telescope: Summary of DR4 and DR5 Data Products and Data Access

“…Optimally combining data from the ACT-MBAC, ACTPol, and AdvACT surveys as well as Planck, the DR5 co-added maps cover the same total ∼18,000 deg 2 sky footprint as DR4 but with a full co-added depth of 10 mK CMB ′ over ∼2500 deg 2 . These maps are ideal for producing cluster catalogs, such as in Section 3.9, and are well suited for stacking analyses such as measurements of the tSZ and kinematic Sunyaev-Zel'dovich (kSZ) effects (Amodeo et al 2021;Schaan et al 2021;Calafut et al 2021;Vavagiakis et al 2021), cluster lensing (Madhavacheril et al 2020b), point-source and cluster studies, and Galactic science. Due to the preliminary nature of the s17-s18 data, the DR5 co-added maps are not recommended for precision cosmology.…”