The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and Its Implications for Structure Growth

Journal Article · 19 February 2024 · The Astrophysical Journal

DOI: https://doi.org/10.3847/1538-4357/acfe06 · OSTI ID:1973421

Qu, Frank J. ^[1]; Sherwin, Blake D.; Madhavacheril, Mathew S. ; Han, Dongwon; Crowley, Kevin T.; Abril-Cabezas, Irene ; Ade, Peter R.; Aiola, Simone ; Alford, Tommy; Amiri, Mandana; Amodeo, Stefania; An, Rui; Atkins, Zachary; Austermann, Jason E. ; Battaglia, Nicholas ; Battistelli, Elia Stefano ; Beall, James A.; Bean, Rachel; Beringue, Benjamin; Bhandarkar, Tanay ; Biermann, Emily; Bolliet, Boris; Bond, J. Richard; Cai, Hongbo; Calabrese, Erminia; Calafut, Victoria; Capalbo, Valentina; Carrero, Felipe; Carron, Julien; Challinor, Anthony; Chesmore, Grace E.; Cho, Hsiao-mei; Choi, Steve K. ; Clark, Susan E. ; Córdova Rosado, Rodrigo; Cothard, Nicholas F.; Coughlin, Kevin; Coulton, William ; Dalal, Roohi; Darwish, Omar; Devlin, Mark J.; Dicker, Simon ; Doze, Peter ; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J. ; Dunkley, Jo ; Dünner, Rolando ; Fanfani, Valentina; Fankhanel, Max; Farren, Gerrit ; Ferraro, Simone; Freundt, Rodrigo; Fuzia, Brittany; Gallardo, Patricio A.; Garrido, Xavier; Gluscevic, Vera; Golec, Joseph E.; Guan, Yilun ; Halpern, Mark ; Harrison, Ian; Hasselfield, Matthew; Healy, Erin; Henderson, Shawn; Hensley, Brandon ; Hervías-Caimapo, Carlos; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt ; Hincks, Adam D. ; Hložek, Renée; Ho, Shuay-Pwu Patty; Huber, Zachary B.; Hubmayr, Johannes; Huffenberger, Kevin M. ; Hughes, John P. ; Irwin, Kent; Isopi, Giovanni ; Jense, Hidde T.; Keller, Ben; Kim, Joshua; Knowles, Kenda ; Koopman, Brian J.; Kosowsky, Arthur ; Kramer, Darby; Kusiak, Aleksandra; La Posta, Adrien; Lague, Alex; Lakey, Victoria; Lee, Eunseong; Li, Zack; Li, Yaqiong; Limon, Michele; Lokken, Martine; Louis, Thibaut; Lungu, Marius; MacCrann, Niall; MacInnis, Amanda; Maldonado, Diego; Maldonado, Felipe; Mallaby-Kay, Maya; Marques, Gabriela A.; McMahon, Jeff; Mehta, Yogesh; Menanteau, Felipe ; Moodley, Kavilan ; Morris, Thomas W.; Mroczkowski, Tony ; Naess, Sigurd ; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nicola, Andrina; Niemack, Michael D.; Nolta, Michael R.; Orlowski-Scherer, John ; Page, Lyman A. ; Pandey, Shivam; Partridge, Bruce; Prince, Heather; Puddu, Roberto; Radiconi, Federico; Robertson, Naomi; Rojas, Felipe; Sakuma, Tai; Salatino, Maria; Schaan, Emmanuel ; Schmitt, Benjamin L.; Sehgal, Neelima ; Shaikh, Shabbir; Sierra, Carlos; Sievers, Jon; Sifón, Cristóbal; Simon, Sara; Sonka, Rita; Spergel, David N. ; Staggs, Suzanne T.; Storer, Emilie; Switzer, Eric R.; Tampier, Niklas; Thornton, Robert; Trac, Hy; Treu, Jesse; Tucker, Carole; Ullom, Joel; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; van Marrewijk, Joshiwa; Vargas, Cristian; Vavagiakis, Eve M.; Wagoner, Kasey; Wang, Yuhan; Wenzl, Lukas ; Wollack, Edward J. ; Xu, Zhilei ; Zago, Fernando; Zheng, Kaiwen

---

1. University of Cambridge (United Kingdom); Kavli Institute for Cosmology Cambridge (United Kingdom); et al.

We present new measurements of cosmic microwave background (CMB) lensing over 9400 deg of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB data set, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at 2.3% precision (43σ significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure that our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. Our CMB lensing power spectrum measurement provides constraints on the amplitude of cosmic structure that do not depend on Planck or galaxy survey data, thus giving independent information about large-scale structure growth and potential tensions in structure measurements. The baseline spectrum is well fit by a lensing amplitude of A_lens = 1.013 ± 0.023 relative to the Planck 2018 CMB power spectra best-fit ΛCDM model and A_lens = 1.005 ± 0.023 relative to the ACT DR4 + WMAP best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination $$S^{CMBL}_{8}$$ ≡ σ₈(Ω_m/0.3)^0.25 of $$S^{CMBL}_{8}$$ = 0.818 ± 0.022 from ACT DR6 CMB lensing alone and $$S^{CMBL}_{8}$$ = 0.813 ± 0.018 when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with ΛCDM model constraints from Planck or ACT DR4 + WMAP CMB power spectrum measurements. Our lensing measurements from redshifts z ~ 0.5–5 are thus fully consistent with ΛCDM structure growth predictions based on CMB anisotropies probing primarily z ~ 1100. We find no evidence for a suppression of the amplitude of cosmic structure at low redshifts.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Aeronautics and Space Administration (NASA)
• Contributing Organization: ACT
• Grant/Contract Number: AC02-07CH11359; AC02-05CH11231
• OSTI ID: 1973421
• Report Number(s): FERMILAB-PUB--23-237-PPD; arXiv:2304.05202; oai:inspirehep.net:2650570
• Journal Information: The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 962; ISSN 0004-637X
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English