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

Author

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

Subjects
Cosmological parameters, Cosmological parameters from large-scale structure, Astrophysics, QB460-466
Abstract

We present new measurements of cosmic microwave background (CMB) lensing over 9400 deg ^2 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 (43 σ 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 ${S}_{8}^{\mathrm{CMBL}}\equiv {\sigma }_{8}{\left({{\rm{\Omega }}}_{m}/0.3\right)}^{0.25}$ of ${S}_{8}^{\mathrm{CMBL}}=0.818\pm 0.022$ from ACT DR6 CMB lensing alone and ${S}_{8}^{\mathrm{CMBL}}=0.813\pm 0.018$ 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.

Published
2024
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2. The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters

Author

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

Subjects
Cosmology, Observational cosmology, Cosmic microwave background radiation, Large-scale structure of the universe, Cosmological neutrinos, Particle astrophysics, Astrophysics, QB460-466
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 and big bang nucleosynthesis, we obtain the clustering amplitude σ _8 = 0.819 ± 0.015 at 1.8% precision, ${S}_{8}\equiv {\sigma }_{8}{({{\rm{\Omega }}}_{{\rm{m}}}/0.3)}^{0.5}=0.840\pm 0.028$ , and the Hubble constant H _0 = (68.3 ± 1.1) km s ^−1 Mpc ^−1 at 1.6% precision. A joint constraint with Planck CMB lensing yields σ _8 = 0.812 ± 0.013, ${S}_{8}\equiv {\sigma }_{8}{({{\rm{\Omega }}}_{{\rm{m}}}/0.3)}^{0.5}=0.831\pm 0.023$ , and H _0 = (68.1 ± 1.0) km s ^−1 Mpc ^−1 . These measurements agree with ΛCDM extrapolations from the CMB anisotropies measured by Planck. We revisit constraints from the KiDS, DES, and HSC galaxy surveys with a uniform set of assumptions and find that S _8 from all three are lower than that from ACT+Planck lensing by levels ranging from 1.7 σ to 2.1 σ . This motivates 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 with CMB anisotropies to constrain extensions of ΛCDM, limiting neutrino masses to ∑ m _ν < 0.13 eV (95% c.l.), for example. We describe the mass map and related data products that will enable a wide array of cross-correlation science. 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 lensing from upcoming ground-based CMB surveys.

Published
2024
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3. Simons Observatory: Characterizing the Large Aperture Telescope Receiver with Radio Holography

Author

Grace. E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, and Zhilei Xu

Subjects
Optics, Instrumentation and Photography
Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022
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5. The Simons Observatory: Characterizing the Large Aperture Telescope Receiver with Radio Holography

Author

Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, Zhilei Xu, Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, and Xu, Z

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Electrical and Electronic Engineering, Astrophysics - Instrumentation and Methods for Astrophysics, Engineering (miscellaneous), Instrumentation and Methods for Astrophysics (astro-ph.IM), Atomic and Molecular Physics, and Optics, optics, Astrophysics::Galaxy Astrophysics
Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022

6. Simons Observatory: characterizing the Large Aperture Telescope Receiver with radio holography

Author

Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, Xu, Z, Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, Zhilei Xu, Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, Xu, Z, Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, and Zhilei Xu

Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022

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