Showing papers by "Peter A. R. Ade published in 2019"
TL;DR: The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s as mentioned in this paper.
Abstract: The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping ≈ 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of σ(r)=0.003. The large aperture telescope will map ≈ 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
1,027 citations
TL;DR: LiteBIRD as mentioned in this paper is a candidate satellite for a strategic large mission of JAXA, which aims to map the polarization of the cosmic microwave background radiation over the full sky with unprecedented precision.
Abstract: LiteBIRD is a candidate satellite for a strategic large mission of JAXA. With its expected launch in the middle of the 2020s with a H3 rocket, LiteBIRD plans to map the polarization of the cosmic microwave background radiation over the full sky with unprecedented precision. The full success of LiteBIRD is to achieve $\delta r < 0.001$ , where $\delta r$ is the total error on the tensor-to-scalar ratio r. The required angular coverage corresponds to $2 \le \ell \le 200$ , where $\ell $ is the multipole moment. This allows us to test well-motivated cosmic inflation models. Full-sky surveys for 3 years at a Lagrangian point L2 will be carried out for 15 frequency bands between 34 and 448 GHz with two telescopes to achieve the total sensitivity of 2.5 $\upmu $ K arcmin with a typical angular resolution of 0.5$^\circ $ at 150 GHz. Each telescope is equipped with a half-wave plate system for polarization signal modulation and a focal plane filled with polarization-sensitive TES bolometers. A cryogenic system provides a 100 mK base temperature for the focal planes and 2 K and 5 K stages for optical components.
286 citations
Journal Article•
TL;DR: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics as mentioned in this paper.
Abstract: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics.
114 citations
TL;DR: In this article, the authors describe the observations and resultant galaxy cluster catalog from the 2770 deg$^2$ SPTpol Extended Cluster Survey (SPT-ECS).
Abstract: We describe the observations and resultant galaxy cluster catalog from the 2770 deg$^2$ SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect, and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete followup we have confirmed as clusters 244 of 266 candidates at a detection significance $\xi \ge 5$ and an additional 204 systems at $4 4$ threshold, and $ 10\% $ of their measured SZ flux. We associate SZ-selected clusters, from both SPT-ECS and the SPT-SZ survey, with clusters from the DES redMaPPer sample, and find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets. Adopting a fixed Planck-like cosmology, we measure the optical richness-to-SZ-mass ($\lambda-M$) relation and find it to be 28% shallower than that from a weak-lensing analysis of the DES data---a difference significant at the 4 $\sigma$ level---with the relations intersecting at $\lambda=60$ . The SPT-ECS cluster sample will be particularly useful for studying the evolution of massive clusters and, in combination with DES lensing observations and the SPT-SZ cluster sample, will be an important component of future cosmological analyses.
83 citations
University of Oslo1, University of Chicago2, Cardiff University3, Fermilab4, National Institute of Standards and Technology5, University of California, Berkeley6, Argonne National Laboratory7, University of Melbourne8, McGill University9, University of KwaZulu-Natal10, California Institute of Technology11, Lawrence Berkeley National Laboratory12, Canadian Institute for Advanced Research13, University of Colorado Boulder14, Harvey Mudd College15, European Southern Observatory16, University of Illinois at Urbana–Champaign17, Stanford University18, University of California, Davis19, University of Paris20, University of Michigan21, University of Minnesota22, Case Western Reserve University23, Yale University24, School of the Art Institute of Chicago25, Harvard University26, University of Toronto27, University of Maryland, College Park28, National Center for Supercomputing Applications29, University of California, Los Angeles30
TL;DR: Wu et al. as discussed by the authors measured the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit Λ cold dark matter model to the Planck 2015 TT + low P + lensing data set.
Abstract: Author(s): Wu, WLK; Mocanu, LM; Ade, PAR; Anderson, AJ; Austermann, JE; Avva, JS; Beall, JA; Bender, AN; Benson, BA; Bianchini, F; Bleem, LE; Carlstrom, JE; Chang, CL; Chiang, HC; Citron, R; Moran, CC; Crawford, TM; Crites, AT; De Haan, TD; Dobbs, MA; Everett, W; Gallicchio, J; George, EM; Gilbert, A; Gupta, N; Halverson, NW; Harrington, N; Henning, JW; Hilton, GC; Holder, GP; Holzapfel, WL; Hou, Z; Hrubes, JD; Huang, N; Hubmayr, J; Irwin, KD; Knox, L; Lee, AT; Li, D; Lowitz, A; Manzotti, A; McMahon, JJ; Meyer, SS; Millea, M; Montgomery, J; Nadolski, A; Natoli, T; Nibarger, JP; Noble, GI; Novosad, V; Omori, Y; Padin, S; Patil, S; Pryke, C; Reichardt, CL; Ruhl, JE; Saliwanchik, BR; Sayre, JT; Schaffer, KK; Sievers, C; Simard, G; Smecher, G; Stark, AA; Story, KT; Tucker, C; Vanderlinde, K; Veach, T; Vieira, JD; Wang, G; Whitehorn, N; Yefremenko, V | Abstract: We present a measurement of the cosmic microwave background lensing potential using 500 deg2 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L ≲ 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 l L l 2000 from sets of temperature-only (T), polarization-only (POL), and minimum-variance (MV) estimators. We measure the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit Λ cold dark matter model to the Planck 2015 TT + low P + lensing data set. For the minimum-variance estimator, we find =0.944 0.025 (Sys.) SRC=restricting to only polarization data, we find POL=0.906\pm 0.090 0.040. Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1σ) and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination.
68 citations
Journal Article•
Maximilian H. Abitbol, Shunsuke Adachi, Peter A. R. Ade, James E. Aguirre +278 more•Institutions (1)
TL;DR: The Simons Observatory (SO) as mentioned in this paper is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics.
Abstract: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. Supported by the Simons Foundation, the Heising-Simons Foundation, and with contributions from collaborating institutions, SO will see first light in 2021 and start a five year survey in 2022. SO has 287 collaborators from 12 countries and 53 institutions, including 85 students and 90 postdocs. The SO experiment in its currently funded form ('SO-Nominal') consists of three 0.4 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT). Optimized for minimizing systematic errors in polarization measurements at large angular scales, the SATs will perform a deep, degree-scale survey of 10% of the sky to search for the signature of primordial gravitational waves. The LAT will survey 40% of the sky with arc-minute resolution. These observations will measure (or limit) the sum of neutrino masses, search for light relics, measure the early behavior of Dark Energy, and refine our understanding of the intergalactic medium, clusters and the role of feedback in galaxy formation. With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in mapping speed over currently operating ("Stage 3") experiments, SO will measure the CMB temperature and polarization fluctuations to exquisite precision in six frequency bands from 27 to 280 GHz. SO will rapidly advance CMB science while informing the design of future observatories such as CMB-S4.
53 citations
National Radio Astronomy Observatory1, Cardiff University2, University of Pennsylvania3, University of California, Berkeley4, Princeton University5, University of Virginia6, University of New South Wales7, National Institute of Standards and Technology8, Nagoya University9, University of California, San Diego10, University of Arizona11, Harvard University12, Brown University13, University of Toronto14, Northwestern University15, California Institute of Technology16, National Institutes of Natural Sciences, Japan17, Sapienza University of Rome18, University of La Laguna19, Spanish National Research Council20, Max Planck Society21, University College London22, University of British Columbia23, Goddard Space Flight Center24, University of Central Lancashire25
TL;DR: In this paper, the authors compare the magnetic field orientation for the young giant molecular cloud Vela C inferred from 500 μm polarization maps made with the BLASTPol balloon-borne polarimeter to the orientation of structures in the integrated line emission maps from Mopra observations.
Abstract: We compare the magnetic field orientation for the young giant molecular cloud Vela C inferred from 500 μm polarization maps made with the BLASTPol balloon-borne polarimeter to the orientation of structures in the integrated line emission maps from Mopra observations. Averaging over the entire cloud we find that elongated structures in integrated line-intensity or zeroth-moment maps, for low-density tracers such as 12CO and 13CO J → 1 – 0, are statistically more likely to align parallel to the magnetic field, while intermediate- or high-density tracers show (on average) a tendency for alignment perpendicular to the magnetic field. This observation agrees with previous studies of the change in relative orientation with column density in Vela C, and supports a model where the magnetic field is strong enough to have influenced the formation of dense gas structures within Vela C. The transition from parallel to no preferred/perpendicular orientation appears to occur between the densities traced by 13CO and by C18O J → 1 – 0. Using RADEX radiative transfer models to estimate the characteristic number density traced by each molecular line, we find that the transition occurs at a molecular hydrogen number density of approximately 103 cm−3. We also see that the Centre Ridge (the highest column density and most active star-forming region within Vela C) appears to have a transition at a lower number density, suggesting that this may depend on the evolutionary state of the cloud.
51 citations
TL;DR: In this article, a measurement of the cosmic microwave background (CMB) lensing potential using 500 deg$^2$ of 150 GHz data from the SPTpol receiver on the South Pole Telescope is presented.
Abstract: We present a measurement of the cosmic microwave background (CMB) lensing potential using 500 deg$^2$ of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles $L \lesssim 250$, using a quadratic estimator on a combination of CMB temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of $100< L < 2000$ from sets of temperature-only, polarization-only, and minimum-variance estimators. We measure the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit $\Lambda$CDM model to the $\textit{Planck}$ 2015 TT+lowP+lensing dataset. For the minimum-variance estimator, we find $A_{\rm{MV}} = 0.944 \pm 0.058{\rm (Stat.)}\pm0.025{\rm (Sys.)}$; restricting to only polarization data, we find $A_{\rm{POL}} = 0.906 \pm 0.090 {\rm (Stat.)} \pm 0.040 {\rm (Sys.)}$. Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1 $\sigma$), and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination.
45 citations
TL;DR: In this article, the authors designed, fabricated, and characterized four arrays of horn-coupled, lumped element kinetic inductance detectors (LEKIDs), optimized to work in the spectral bands of the balloon-borne OLIMPO experiment.
Abstract: We designed, fabricated, and characterized four arrays of horn-coupled, lumped element kinetic inductance detectors (LEKIDs), optimized to work in the spectral bands of the balloon-borne OLIMPO experiment. OLIMPO is a 2.6 m aperture telescope, aimed at spectroscopic measurements of the Sunyaev-Zel'dovich (SZ) effect. OLIMPO will also validate the LEKID technology in a representative space environment. The corrected focal plane is filled with diffraction limited horn-coupled KID arrays, with 19, 37, 23, 41 active pixels respectively at 150, 250, 350, and 460 GHz. Here we report on the full electrical and optical characterization performed on these detector arrays before the flight. In a dark laboratory cryostat, we measured the resonator electrical parameters, such as the quality factors and the electrical responsivities, at a base temperature of 300 mK. The measured average resonator Qs are 1.7× 104, 7.0× 103, 1.0× 104, and 1.0× 104 for the 150, 250, 350, and 460 GHz arrays, respectively. The average electrical phase responsivities on resonance are 1.4 rad/pW, 1.5 rad/pW, 2.1 rad/pW, and 2.1 rad/pW; the electrical noise equivalent powers are 45 aW/√Hz, 160 aW/√Hz, 80 aW/√Hz, and 140 aW/√Hz, at 12 Hz. In the OLIMPO cryostat, we measured the optical properties, such as the noise equivalent temperatures (NET) and the spectral responses. The measured NETRJs are 200 μ K.√s, 240 μK √s, 240 μK √s, and 340 μK √s, at 12 Hz; under 78, 88, 92, and 90 mK Rayleigh-Jeans blackbody load changes respectively for the 150, 250, 350, and 460 GHz arrays. The spectral responses were characterized with the OLIMPO differential Fourier transform spectrometer (DFTS) up to THz frequencies, with a resolution of 1.8 GHz.
32 citations
University of Melbourne1, University of California, Los Angeles2, University of Pennsylvania3, University of Chicago4, Fermilab5, Argonne National Laboratory6, Canadian Institute for Advanced Research7, McGill University8, University of Arizona9, Ludwig Maximilian University of Munich10, Max Planck Society11, Cardiff University12, National Institute of Standards and Technology13, University of Portsmouth14, University of Paris15, University College London16, Stanford University17, IFAE18, University of KwaZulu-Natal19, California Institute of Technology20, Indian Institute of Technology, Hyderabad21, University of Colorado Boulder22, University of Michigan23, Spanish National Research Council24, Harvey Mudd College25, Autonomous University of Madrid26, University of California, Berkeley27, European Southern Observatory28, University of Illinois at Urbana–Champaign29, Lawrence Berkeley National Laboratory30, ETH Zurich31, University of California, Santa Cruz32, Ohio State University33, Harvard University34, University of California, Davis35, Australian Astronomical Observatory36, University of São Paulo37, Texas A&M University38, Princeton University39, University of Toronto40, University of Minnesota41, Ames Research Center42, University of Sussex43, Case Western Reserve University44, School of the Art Institute of Chicago45, Brandeis University46, State University of Campinas47, Oak Ridge National Laboratory48
TL;DR: In this paper, a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel{'dovich (tSZ) effect was used to estimate the background CMB gradient.
Abstract: We use cosmic microwave background (CMB) temperature maps from the 500 deg2 SPTpol survey to measure the stacked lensing convergence of galaxy clusters from the Dark Energy Survey (DES) Year-3 redMaPPer (RM) cluster catalog. The lensing signal is extracted through a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel{'}dovich (tSZ) effect. The modified estimator uses a tSZ-free map, constructed from the SPTpol 95 and 150 GHz datasets, to estimate the background CMB gradient. For lensing reconstruction, we employ two versions of the RM catalog: a flux-limited sample containing 4003 clusters and a volume-limited sample with 1741 clusters. We detect lensing at a significance of 8.7 σ (6.7σ) with the flux(volume)-limited sample. By modeling the reconstructed convergence using the Navarro-Frenk-White profile, we find the average lensing masses to be M200m = (1.62 +0.32 −0.25 [stat.] ± 0.04 [sys.]) and (1.28 +0.14 −0.18 [stat.] ±0.03 [sys.])×1014 M⊙for the volume- and flux-limited samples respectively. The systematic error budget is much smaller than the statistical uncertainty and is dominated by the uncertainties in the RM cluster centroids. We use the volume-limited sample to calibrate the normalization of the mass-richness scaling relation, and find a result consistent with the galaxy weak-lensing measurements from DES (Mcclintock et al. 2018).
28 citations
Posted Content•
Maximilian H. Abitbol, Shunsuke Adachi, Peter A. R. Ade, James E. Aguirre +278 more•Institutions (2)
TL;DR: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics.
Abstract: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. Supported by the Simons Foundation, the Heising-Simons Foundation, and with contributions from collaborating institutions, SO will see first light in 2021 and start a five year survey in 2022. SO has 287 collaborators from 12 countries and 53 institutions, including 85 students and 90 postdocs.
The SO experiment in its currently funded form ('SO-Nominal') consists of three 0.4 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT). Optimized for minimizing systematic errors in polarization measurements at large angular scales, the SATs will perform a deep, degree-scale survey of 10% of the sky to search for the signature of primordial gravitational waves. The LAT will survey 40% of the sky with arc-minute resolution. These observations will measure (or limit) the sum of neutrino masses, search for light relics, measure the early behavior of Dark Energy, and refine our understanding of the intergalactic medium, clusters and the role of feedback in galaxy formation.
With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in mapping speed over currently operating ("Stage 3") experiments, SO will measure the CMB temperature and polarization fluctuations to exquisite precision in six frequency bands from 27 to 280 GHz. SO will rapidly advance CMB science while informing the design of future observatories such as CMB-S4.
University of Melbourne1, Cardiff University2, Fermilab3, University of Illinois at Urbana–Champaign4, National Institute of Standards and Technology5, University of California, Berkeley6, Argonne National Laboratory7, University of Chicago8, University of KwaZulu-Natal9, California Institute of Technology10, Lawrence Berkeley National Laboratory11, Canadian Institute for Advanced Research12, McGill University13, University of Colorado Boulder14, Harvey Mudd College15, European Southern Observatory16, Stanford University17, University of California, Davis18, University of Arizona19, University of Michigan20, Ludwig Maximilian University of Munich21, Max Planck Society22, University of Toronto23, University of Minnesota24, Case Western Reserve University25, School of the Art Institute of Chicago26, Harvard University27, Goddard Space Flight Center28, University of Maryland, College Park29, University of California, Los Angeles30
TL;DR: Gupta et al. as mentioned in this paper studied the polarization properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg2 survey and found that the polarization fraction depends on the source flux or observing frequency.
Abstract: Author(s): Gupta, N; Reichardt, CL; Ade, PAR; Anderson, AJ; Archipley, M; Austermann, JE; Avva, JS; Beall, JA; Bender, AN; Benson, BA; Bianchini, F; Bleem, LE; Carlstrom, JE; Chang, CL; Chiang, HC; Citron, R; Corbett Moran, C; Crawford, TM; Crites, AT; de Haan, T; Dobbs, MA; Everett, W; Feng, C; Gallicchio, J; George, EM; Gilbert, A; Halverson, NW; Harrington, N; Henning, JW; Hilton, GC; Holder, GP; Holzapfel, WL; Hou, Z; Hrubes, JD; Huang, N; Hubmayr, J; Irwin, KD; Knox, L; Lee, AT; Li, D; Lowitz, A; Luong-Van, D; Marrone, DP; McMahon, JJ; Meyer, SS; Mocanu, LM; Mohr, JJ; Montgomery, J; Nadolski, A; Natoli, T; Nibarger, JP; Noble, GI; Novosad, V; Padin, S; Patil, S; Pryke, C; Ruhl, JE; Saliwanchik, BR; Sayre, JT; Schaffer, KK; Shirokoff, E; Sievers, C; Smecher, G; Staniszewski, Z; Stark, AA; Story, KT; Switzer, ER; Tucker, C; Vanderlinde, K; Veach, T; Vieira, JD; Wang, G; Whitehorn, N; Williamson, R; Wu, WLK; Yefremenko, V; Zhang, L | Abstract: We study the polarization properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg2 survey. We estimate the polarized power by stacking maps at known source positions, and correct for noise bias by subtracting the mean polarized power at random positions in the maps. We show that the method is unbiased using a set of simulated maps with similar noise properties to the real SPTpol maps. We find a flux-weighted mean-squared polarization fraction 〈p2〉= [8.9 ± 1.1] × 10−4 at 95 GHz and [6.9 ± 1.1] × 10−4 at 150 GHz for the full sample. This is consistent with the values obtained for a subsample of active galactic nuclei. For dusty sources, we find 95 per cent upper limits of 〈p2〉95 l 16.9 × 10−3 and 〈p2〉150 l 2.6 × 10−3. We find no evidence that the polarization fraction depends on the source flux or observing frequency. The 1σ upper limit on measured mean-squared polarization fraction at 150 GHz implies that extragalactic foregrounds will be subdominant to the CMB E and B mode polarization power spectra out to at least l ≲ 5700 (l ≲ 4700) and l ≲ 5300 (l ≲ 3600), respectively, at 95 (150) GHz.
University of Milan1, Cardiff University2, Sapienza University of Rome3, INAF4, University of Richmond5, University of Surrey6, National University of La Plata7, University of Wisconsin-Madison8, National University of Ireland, Galway9, University of Manchester10, Brown University11, National University of General San Martín12, Institute of Technology, Carlow13, Istituto Nazionale di Fisica Nucleare14
TL;DR: In this paper, the authors describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control typical of interferometers.
Abstract: In this paper, we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control typical of interferometers. QUBIC’s unique features are the so-called “self-calibration”, a technique that allows us to clean the measured data from instrumental effects, and its spectral imaging power, i.e., the ability to separate the signal into various sub-bands within each frequency band. QUBIC will observe the sky in two main frequency bands: 150 GHz and 220 GHz. A technological demonstrator is currently under testing and will be deployed in Argentina during 2019, while the final instrument is expected to be installed during 2020.
TL;DR: In this paper, the performance of lumped-elements Kinetic Inductance Detector (KID) arrays for mm and sub-mm wavelengths, operated at 0.3 K during the stratospheric flight of the OLIMPO payload, at an altitude of 37.8 km.
Abstract: We report on the performance of lumped-elements Kinetic Inductance Detector (KID) arrays for mm and sub-mm wavelengths, operated at 0.3 K during the stratospheric flight of the OLIMPO payload, at an altitude of 37.8 km. We find that the detectors can be tuned in-flight, and their performance is robust against radiative background changes due to varying telescope elevation. We also find that the noise equivalent power of the detectors in flight is smaller by a factor of ~ 2, 8, 3.5, 4.5 at 150, 250, 350 and 460 GHz relative to the one measured in the laboratory, and is close to our calculated photon-noise-limited performance. The effect of primary cosmic rays crossing the detector is found to be consistent with the expected ionization energy loss with phonon-mediated energy transfer from the ionization sites to the resonators. In the OLIMPO detector arrays, at float, cosmic ray events affect less than 4% of the detector samplings for all the pixels of all the arrays, and less than 1% of the samplings for most of the pixels. These results are also representative of what one can expect from primary cosmic rays in a satellite mission with similar KIDs and instrument environment.
Argonne National Laboratory1, University of Chicago2, Fermilab3, University of California, Berkeley4, Cardiff University5, SLAC National Accelerator Laboratory6, Stanford University7, McGill University8, National Institute of Standards and Technology9, Canadian Institute for Advanced Research10, University of Colorado Boulder11, University of California, Los Angeles12, Case Western Reserve University13, University of Illinois at Urbana–Champaign14, Harvey Mudd College15, Lawrence Berkeley National Laboratory16, University of Toronto17, Harvard University18
TL;DR: In this article, the authors present the successful implementation and performance of the SPT-3G readout as measured on-sky, indicating that lowfrequency noise in the readout will not limit SPT3G's measurements of sky power on large angular scales.
Abstract: Frequency-domain multiplexing (fMux) is an established technique for the readout of large arrays of transition edge sensor (TES) bolometers. Each TES in a multiplexing module has a unique AC voltage bias that is selected by a resonant filter. This scheme enables the operation and readout of multiple bolometers on a single pair of wires, reducing thermal loading onto sub-Kelvin stages. The current receiver on the South Pole Telescope, SPT-3G, uses a 68x fMux system to operate its large-format camera of $\sim$16,000 TES bolometers. We present here the successful implementation and performance of the SPT-3G readout as measured on-sky. Characterization of the noise reveals a median pair-differenced 1/f knee frequency of 33 mHz, indicating that low-frequency noise in the readout will not limit SPT-3G's measurements of sky power on large angular scales. Measurements also show that the median readout white noise level in each of the SPT-3G observing bands is below the expectation for photon noise, demonstrating that SPT-3G is operating in the photon-noise-dominated regime.
University of California, Los Angeles1, University of Melbourne2, University of Pennsylvania3, Fermilab4, University of Chicago5, Argonne National Laboratory6, Canadian Institute for Advanced Research7, University of Illinois at Urbana–Champaign8, University of Arizona9, Ludwig Maximilian University of Munich10, Max Planck Society11, Cardiff University12, National Institute of Standards and Technology13, Autonomous University of Madrid14, University of California, Berkeley15, University of Portsmouth16, University College London17, Stanford University18, IFAE19, Spanish National Research Council20, University of KwaZulu-Natal21, California Institute of Technology22, Indian Institute of Technology, Hyderabad23, McGill University24, University of California, Santa Cruz25, University of Michigan26, Harvey Mudd College27, European Southern Observatory28, University of Cambridge29, Lawrence Berkeley National Laboratory30, University of Colorado Boulder31, Ohio State University32, University of California, Davis33, University of São Paulo34, Texas A&M University35, Princeton University36, University of Toronto37, University of Minnesota38, Ames Research Center39, University of Sussex40, Case Western Reserve University41, Yale University42, School of the Art Institute of Chicago43, University of Southampton44, Brandeis University45, Harvard University46, Oak Ridge National Laboratory47, University of Maryland, College Park48
TL;DR: This detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB) is reported, a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.
Abstract: We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.
University of Toronto1, Cardiff University2, University of Pennsylvania3, University of California, Berkeley4, Princeton University5, National Institute of Standards and Technology6, National Radio Astronomy Observatory7, Nagoya University8, University of California, San Diego9, Goddard Space Flight Center10, Johns Hopkins University11, Brown University12, University of Virginia13, Northwestern University14, California Institute of Technology15, National Institutes of Natural Sciences, Japan16, Max Planck Society17, Sapienza University of Rome18, University College London19, University of British Columbia20, University of Central Lancashire21
TL;DR: In particular, there is no evidence for a pronounced minimum of the spectrum near 350 μm, as suggested by previous ground-based measurements of other molecular clouds as mentioned in this paper, which is consistent with recently published BLASTPol measurements of the Vela C molecular cloud and also agrees with a published model for an externally illuminated, dense molecular cloud by Bethell and collaborators.
Abstract: Linear polarization maps of the Carina Nebula were obtained at 250, 350, and 500 μm during the 2012 flight of the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol). These measurements are combined with Planck 850 μm data in order to produce a submillimeter spectrum of the polarization fraction of the dust emission, averaged over the cloud. This spectrum is flat to within ±15% (relative to the 350 μm polarization fraction). In particular, there is no evidence for a pronounced minimum of the spectrum near 350 μm, as suggested by previous ground-based measurements of other molecular clouds. This result of a flat polarization spectrum in Carina is consistent with recently published BLASTPol measurements of the Vela C molecular cloud and also agrees with a published model for an externally illuminated, dense molecular cloud by Bethell and collaborators. The shape of the spectrum in Carina does not show any dependence on the radiative environment of the dust, as quantified by the Planck-derived dust temperature or dust optical depth at 353 GHz.
Goddard Space Flight Center1, Cardiff University2, University of Michigan3, NASA Headquarters4, Johns Hopkins University5, Villanova University6, University of Maryland, College Park7, University of British Columbia8, National Institute of Standards and Technology9, Stanford University10, SLAC National Accelerator Laboratory11
TL;DR: The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe as mentioned in this paper, which employs two 32 × 40 arrays of superconducting transition-edge sensors.
Abstract: The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe. PIPER employs two 32 × 40 arrays of superconducting transition-edge sensors, which operate at 100 mK. An open bucket Dewar of liquid helium maintains the receiver and telescope optics at 1.7 K. We describe the thermal design of the receiver and sub-Kelvin cooling with a continuous adiabatic demagnetization refrigerator (CADR). The CADR operates between 70 and 130 mK and provides ≈10 μW cooling power at 100 mK, nearly five times the loading of the two detector assemblies. We describe electronics and software to robustly control the CADR, overall CADR performance in flightlike integrated receiver testing, and practical considerations for implementation in the balloon float environment.
TL;DR: In this article, the authors describe an on-sky demonstration of a microwave-multiplexing readout system in one of the receivers of the Keck Array, a polarimetry experiment observing the cosmic microwave background at the South Pole.
Abstract: We describe an on-sky demonstration of a microwave-multiplexing readout system in one of the receivers of the Keck Array, a polarimetry experiment observing the cosmic microwave background at the South Pole. During the austral summer of 2018-2019, we replaced the time-division multiplexing readout system with microwave-multiplexing components including superconducting microwave resonators coupled to radio-frequency superconducting quantum interference devices at the sub-Kelvin focal plane, coaxial-cable plumbing and amplification between room temperature and the cold stages, and a SLAC Microresonator Radio Frequency system for the warm electronics. In the range 5-6 GHz, a single coaxial cable reads out 528 channels. The readout system is coupled to transition-edge sensors, which are in turn coupled to 150-GHz slot-dipole phased-array antennas. Observations began in April 2019, and we report here on an initial characterization of the system performance.
TL;DR: In this paper, the authors present two prescriptions for broadband (~77 - 252 GHz), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements, in their case 5 mm diameter half-spheres (called "lenslets").
Abstract: We present two prescriptions for broadband (~77 - 252 GHz), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements, in our case 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially-available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves (97 +/- 2)% transmittance and the lenslet coating sample achieves (94 +/- 3)% transmittance.
Cardiff University1, Stanford University2, California Institute of Technology3, Harvard University4, Princeton University5, University of Cincinnati6, University of Minnesota7, French Alternative Energies and Atomic Energy Commission8, University of Illinois at Urbana–Champaign9, University of British Columbia10, National Institute of Standards and Technology11, University of California, San Diego12, Canadian Institute for Advanced Research13, University of Toronto14, Brookhaven National Laboratory15, University of Chicago16
TL;DR: In this paper, a cosmological constraint from observations with the BICEP2 and Keck Array experiments up to and including the 2015 observing season (BK15) was presented, resulting in the deepest CMB polarization maps to date.
Abstract: Precision measurements of cosmic microwave background (CMB) polarization require extreme control of instrumental systematics. In a companion paper we have presented cosmological constraints from observations with the BICEP2 and Keck Array experiments up to and including the 2015 observing season (BK15), resulting in the deepest CMB polarization maps to date and a statistical sensitivity to the tensor-to-scalar ratio of σ(r) = 0.020. In this work we characterize the beams and constrain potential systematic contamination from main beam shape mismatch at the three BK15 frequencies (95, 150, and 220 GHz). Far-field maps of 7360 distinct beam patterns taken from 2010–2015 are used to measure differential beam parameters and predict the contribution of temperature-to-polarization leakage to the BK15 B-mode maps. In the multifrequency, multicomponent likelihood analysis that uses BK15, Planck, and Wilkinson Microwave Anisotropy Probe maps to separate sky components, we find that adding this predicted leakage to simulations induces a bias of Δr = 0.0027 ± 0.0019. Future results using higher-quality beam maps and improved techniques to detect such leakage in CMB data will substantially reduce this uncertainty, enabling the levels of systematics control needed for BICEP Array and other experiments that plan to definitively probe large-field inflation.
TL;DR: A novel two-output port configuration for a THz-Time Domain Spectroscopy (TDS) system with optimized polarimetry for Jones matrix measurements is described and the system’s performance is described highlighting some of the advantages of this system in one of its two modes of operation.
Abstract: We describe the design, build and characterization of a novel two-output port configuration for a THz-Time Domain Spectroscopy (TDS) system. By introducing a tilted THz ultra-broadband polarizer, we split the THz beam in two orthogonal polarization detector branches. The probe laser is similarly split (with an optical polarizer) replicating the detection chain to obtain two independent orthogonal polarization detection units. We describe the system’s performance highlighting some of the advantages of this system in one of its two modes of operation: optimized polarimetry for Jones matrix measurements. A bi-refringent sapphire standard was measured to confirm its capabilities and assess the performance of the system showing good agreement with existing literature data.
TL;DR: In this paper, the performance of lumped-elements Kinetic Inductance Detector (KID) arrays for mm and sub-mm wavelengths, operated at 0.3K during the stratospheric flight of the OLIMPO payload, at an altitude of 37.8 km.
Abstract: We report on the performance of lumped--elements Kinetic Inductance Detector (KID) arrays for mm and sub--mm wavelengths, operated at 0.3K during the stratospheric flight of the OLIMPO payload, at an altitude of 37.8 km. We find that the detectors can be tuned in-flight, and their performance is robust against radiative background changes due to varying telescope elevation. We also find that the noise equivalent power of the detectors in flight is significantly reduced with respect to the one measured in the laboratory, and close to photon-noise limited performance. The effect of primary cosmic rays crossing the detector is found to be consistent with the expected ionization energy loss with phonon-mediated energy transfer from the ionization sites to the resonators. In the OLIMPO detector arrays, at float, cosmic ray events affect less than 4% of the detector samplings for all the pixels of all the arrays, and less than 1% of the samplings for most of the pixels. These results are also representative of what one can expect from primary cosmic rays in a satellite mission with similar KIDs and instrument environment.
University of California, Berkeley1, Argonne National Laboratory2, Harvard University3, Cardiff University4, Stanford University5, Fermilab6, National Institute of Standards and Technology7, University of Chicago8, University of Melbourne9, Ludwig Maximilian University of Munich10, University of Missouri–Kansas City11, McGill University12, University of KwaZulu-Natal13, California Institute of Technology14, Lawrence Berkeley National Laboratory15, Canadian Institute for Advanced Research16, University of Colorado Boulder17, Harvey Mudd College18, European Southern Observatory19, University of Illinois at Urbana–Champaign20, University of California, Davis21, Massachusetts Institute of Technology22, University of Michigan23, University of Oslo24, University of Toronto25, University of Minnesota26, Case Western Reserve University27, Yale University28, University of Trieste29, School of the Art Institute of Chicago30, University of Maryland, College Park31, University of California, Los Angeles32
TL;DR: In this article, the authors presented a catalog of galaxy cluster candidates detected in 100 square degrees surveyed with the SPTpol receiver on the South Pole Telescope, which contains 89 candidates detected with a signal-to-noise ratio greater than 4.6.
Abstract: We present a catalog of galaxy cluster candidates detected in 100 square degrees surveyed with the SPTpol receiver on the South Pole Telescope. The catalog contains 89 candidates detected with a signal-to-noise ratio greater than 4.6. The candidates are selected using the Sunyaev-Zel'dovich effect at 95 and 150 GHz. Using both space- and ground-based optical and infrared telescopes, we have confirmed 81 candidates as galaxy clusters. We use these follow-up images and archival images to estimate photometric redshifts for 66 galaxy clusters and spectroscopic observations to obtain redshifts for 13 systems. An additional 2 galaxy clusters are confirmed using the overdensity of near-infrared galaxies only, and are presented without redshifts. We find that 15 candidates (18% of the total sample) are at redshift of $z \geq 1.0$, with a maximum confirmed redshift of $z_{\rm{max}} = 1.38 \pm 0.10$. We expect this catalog to contain every galaxy cluster with $M_{500c} > 2.6 \times 10^{14} M_\odot h^{-1}_{70}$ and $z > 0.25$ in the survey area. The mass threshold is approximately constant above $z = 0.25$, and the complete catalog has a median mass of approximately $ M_{500c} = 2.7 \times 10^{14} M_\odot h^{-1}_{70}$. Compared to previous SPT works, the increased depth of the millimeter-wave data (11.2 and 6.5 $\mu$K-arcmin at 95 and 150 GHz, respectively) makes it possible to find more galaxy clusters at high redshift and lower mass.
TL;DR: The Polarized Instrument for Longwavelength Observation of the Tenuous Interstellar Medium (PILOT) is a balloon-borne experiment that aims to measure the polarized emission of thermal dust at a wavelength of 240 µm (1.2 THz) as discussed by the authors.
Abstract: The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (PILOT) is a balloon-borne experiment that aims to measure the polarized emission of thermal dust at a wavelength of 240 µm (1.2 THz). A first PILOT flight of the experiment took place from Timmins, Ontario, Canada, in September 2015 and a second flight took place from Alice Springs, Australia in April 2017. In this paper, we present the inflight performance of the instrument. Here we concentrate on the instrument performance as measured during the second flight, but refer to the performance observed during the first flight, if it was significantly different. We present a short description of the instrument and the flights. We measure the time constants of the detectors using the decay of the observed signal during flight following high energy particle impacts (glitches) and switching off the instrument’s internal calibration source. We use these time constants to deconvolve the timelines and analyze the optical quality of the instrument as measured on planets. We then analyze the structure and polarization of the instrumental background. We measure the detector response flat field and its time variations using the signal from the residual atmosphere and from the internal calibration source. Finally, we analyze the spectral and temporal properties of the detector noise. The inflight performance is found to be satisfactory and globally in line with expectations from ground calibrations. We conclude by assessing the expected inflight sensitivity of the instrument in light of the measured inflight performance.
21 Oct 2019
TL;DR: In this paper, the resonant wavelength of an FPI is tuned by changing the spacing or medium between the parallel reflecting plates of the etalon, which simplifies the cryo-mechanical design, actuation and metrology.
Abstract: The sensitivity of state-of-the-art superconducting far-infrared detectors is such that astronomical observations at these wavelengths are limited by photon noise from the astronomical source unless a method of restricting the spectral bandpass is employed. One such method is to use a high resolution Fabry-Perot interferometer (FPI) in conjunction with a lower resolution, post-dispersing system, such as a grating spectrometer. The resonant wavelength of an FPI is typically tuned by changing the spacing or medium between the parallel reflecting plates of the etalon. We previously reported on a novel design in which the wavelength is tuned by scanning the angle of incidence, which simplifies the cryo-mechanical design, actuation and metrology. Here we present first light results from the realized instrument.
TL;DR: In this article, the NIKA2 SZ large program is presented, aiming at observing a large sample of clusters at redshifts between 0.5 and 0.9.
Abstract: The main limiting factor of cosmological analyses based on thermal Sunyaev-Zel'dovich (SZ) cluster statistics comes from the bias and systematic uncertainties that affect the estimates of the mass of galaxy clusters. High-angular resolution SZ observations at high redshift are needed to study a potential redshift or morphology dependence of both the mean pressure profile and of the mass-observable scaling relation used in SZ cosmological analyses. The NIKA2 camera is a new generation continuum instrument installed at the IRAM 30-m telescope. With a large field of view, a high angular resolution and a high-sensitivity, the NIKA2 camera has unique SZ mapping capabilities. In this paper, we present the NIKA2 SZ large program, aiming at observing a large sample of clusters at redshifts between 0.5 and 0.9, and the characterization of the first cluster oberved with NIKA2.
University of Paris-Sud1, École Polytechnique2, Cardiff University3, Paris Diderot University4, University of Grenoble5, Sapienza University of Rome6, Spanish National Research Council7, Aix-Marseille University8, PSL Research University9, Arizona State University10, Institut d'Astrophysique de Paris11, Massachusetts Institute of Technology12
TL;DR: The NIKA2 polarimeter consists of a room temperature continuously rotating multi-mesh HWP and a cold polarizer that separates the two orthogonal polarizations onto two 260 GHz KIDs arrays as mentioned in this paper.
Abstract: The NIKA2 polarization channel at 260 GHz (1.15 mm) has been proposed primarily to observe galactic star-forming regions and probe the critical scales between 0.01-0.05 pc at which magnetic field lines may channel the matter of interstellar filaments into growing dense cores. The NIKA2 polarimeter consists of a room temperature continuously rotating multi-mesh HWP and a cold polarizer that separates the two orthogonal polarizations onto two 260 GHz KIDs arrays. We describe in this paper the preliminary results obtained during the most recent commissioning campaign performed in December 2018. We concentrate here on the analysis of the extended sources, while the observation of compact sources is presented in a companion paper [12]. We present preliminary NIKA2 polarization maps of the Crab nebula. We find that the integrated polarization intensity flux measured by NIKA2 is consistent with this http URL terms of polarization angle, we are still limited by systematic uncertainties that will be further investigated in the forthcoming commissioning campaigns.
University of Colorado Boulder1, Cardiff University2, SLAC National Accelerator Laboratory3, Stanford University4, Fermilab5, University of Chicago6, National Institute of Standards and Technology7, University of California, Berkeley8, Argonne National Laboratory9, McGill University10, Canadian Institute for Advanced Research11, Case Western Reserve University12, University of Illinois at Urbana–Champaign13, Lawrence Berkeley National Laboratory14, University of Toronto15, Harvard University16, University of California, Los Angeles17
TL;DR: The South Pole Telescope 3G (SPT-3G) as discussed by the authors is the third generation camera, which was installed on the south pole telescope to map the polarization of the cosmic microwave background.
Abstract: During the austral summer of 2016-17, the third-generation camera, SPT-3G, was installed on the South Pole Telescope, increasing the detector count in the focal plane by an order of magnitude relative to the previous generation. Designed to map the polarization of the cosmic microwave background, SPT-3G contains ten 6-in-hexagonal modules of detectors, each with 269 trichroic and dual-polarization pixels, read out using 68x frequency-domain multiplexing. Here we discuss design, assembly, and layout of the modules, as well as early performance characterization of the first-year array, including yield and detector properties.
University of Chicago1, Fermilab2, Cardiff University3, Stanford University4, SLAC National Accelerator Laboratory5, University of California, Berkeley6, Argonne National Laboratory7, McGill University8, National Institute of Standards and Technology9, Canadian Institute for Advanced Research10, University of Colorado Boulder11, University of California, Los Angeles12, Case Western Reserve University13, University of Illinois at Urbana–Champaign14, Harvey Mudd College15, Lawrence Berkeley National Laboratory16, University of Toronto17, Harvard University18
TL;DR: In this paper, the authors present the results of in-lab characterization and on-sky performance of the Al-Mn wafer, including electrical and thermal properties, optical efficiency measurements, and noise-equivalent temperature.
Abstract: SPT-3G is a polarization-sensitive receiver, installed on the South Pole Telescope, that measures the anisotropy of the cosmic microwave background (CMB) from degree to arcminute scales. The receiver consists of ten 150~mm-diameter detector wafers, containing a total of 16,000 transition-edge sensor (TES) bolometers observing at 95, 150, and 220 GHz. During the 2018-2019 austral summer, one of these detector wafers was replaced by a new wafer fabricated with Al-Mn TESs instead of the Ti/Au design originally deployed for SPT-3G. We present the results of in-lab characterization and on-sky performance of this Al-Mn wafer, including electrical and thermal properties, optical efficiency measurements, and noise-equivalent temperature. In addition, we discuss and account for several calibration-related systematic errors that affect measurements made using frequency-domain multiplexing readout electronics.