Showing papers by "Peter A. R. Ade published in 2020"
Princeton University1, Cardiff University2, Pontifical Catholic University of Chile3, Université Paris-Saclay4, University of Pennsylvania5, University of Oxford6, Johns Hopkins University7, University of British Columbia8, Cornell University9, National Institute of Standards and Technology10, University of Michigan11, University of Toronto12, University of Chile13, University of Chicago14, Stanford University15, University of KwaZulu-Natal16, University of California, Berkeley17, University of Cambridge18, Goddard Space Flight Center19, Lawrence Berkeley National Laboratory20, Florida State University21, University of Southern California22, University of Arizona23, University of Pittsburgh24, Stony Brook University25, Pennsylvania State University26, Columbia University27, Rutgers University28, Yale University29, Perimeter Institute for Theoretical Physics30, University of Illinois at Urbana–Champaign31, University of Milan32, Haverford College33, California Institute of Technology34, McGill University35, Pontifical Catholic University of Valparaíso36, West Chester University of Pennsylvania37, Carnegie Mellon University38, Arizona State University39
TL;DR: In this article, the Atacama Cosmology Telescope (ACT) data were used to estimate the temperature and polarization anisotropy from the cosmic microwave background (CMB) at 98 and 150 GHz.
Abstract: We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013–2016 at 98 and 150 GHz. The maps cover more than 17,000 deg2, the deepest 600 deg2 with noise levels below 10μK-arcmin. We use the power spectrum derived from almost 6,000 deg2 of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, H0. By combining ACT data with large-scale information from WMAP we measure H0=67.6± 1.1 km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured Planck satellite estimate (from ACT alone we find H0=67.9± 1.5 km/s/Mpc). The ΛCDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1σ; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with ΛCDM predictions to within 1.5–2.2σ. We compare ACT, WMAP, and Planck at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.
298 citations
TL;DR: In this paper, the Atacama Cosmology Telescope (ACT) data were used to obtain arcminute-resolution maps of the cosmic microwave background temperature and polarization anisotropy.
Abstract: We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013-2016 at 98 and 150 GHz. The maps cover more than 17,000 deg$^2$, the deepest 600 deg$^2$ with noise levels below $10$ $\mu$K-arcmin. We use the power spectrum derived from almost 6,000 deg$^2$ of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, $H_0$. By combining ACT data with large-scale information from WMAP we measure $H_0=67.6\pm 1.1$ km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured Planck satellite estimate (from ACT alone we find $H_0=67.9\pm 1.5$ km/s/Mpc). The $\Lambda$CDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1$\sigma$; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with $\Lambda$CDM predictions to within 1.5-2$\sigma$. We compare ACT, WMAP, and Planck at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.
287 citations
Princeton University1, Cornell University2, Pennsylvania State University3, Yale University4, University of Pennsylvania5, University of Oxford6, Johns Hopkins University7, Cardiff University8, University of British Columbia9, National Institute of Standards and Technology10, University of Michigan11, University of Toronto12, University of Chile13, University of Chicago14, Stanford University15, University of KwaZulu-Natal16, University of California, Berkeley17, University of Cambridge18, Pontifical Catholic University of Chile19, Goddard Space Flight Center20, Lawrence Berkeley National Laboratory21, Florida State University22, University of Southern California23, University of Arizona24, University of Pittsburgh25, Stony Brook University26, Columbia University27, Rutgers University28, Université Paris-Saclay29, Perimeter Institute for Theoretical Physics30, University of Illinois at Urbana–Champaign31, University of Milan32, Haverford College33, California Institute of Technology34, McGill University35, Pontifical Catholic University of Valparaíso36, West Chester University of Pennsylvania37, Carnegie Mellon University38, Arizona State University39
TL;DR: The National Science Foundation (NSF) as mentioned in this paper gave the first round of the 2019 ERC Starting Grant to the National Research Foundation (NRCF) in South Africa, with a grant of £1.5 million.
Abstract: National Science Foundation (NSF) AST0408698
AST-0965625
AST-1440226
PHY0355328
PHY-0855887
PHY-1214379
Princeton University
University of Pennsylvania
Canada Foundation for Innovation
CFI under the Compute Canada
Government of Ontario
Ontario Research Fund \ Research Excellence
University of Toronto
Simons Foundation
National Aeronautics & Space Administration (NASA) NNX13AE56G
NNX14AB58G
National Institute of Standards & Technology (NIST) - USA
Cornell Presidential Postdoctoral Fellowship
Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) BASAL CATA AFB-170002
National Science Foundation (NSF) AST-1814971
AST1454881
AST-1513618
AST-1907657
AST-1910021
National Research Foundation - South Africa
STFC Ernest Rutherford Fellowship ST/M004856/2
STFC Consolidated Grant ST/S00033X/1
Horizon 2020 ERC Starting Grant 849169
Dicke Fellowship
Mishrahi and Wilkinson funds
CIfAR's Gravity & the Extreme Universe Program
CGIAR
Dunlap Institute
125 citations
Princeton University1, Cornell University2, Pennsylvania State University3, Yale University4, University of Pennsylvania5, University of Oxford6, Johns Hopkins University7, Cardiff University8, University of British Columbia9, National Institute of Standards and Technology10, University of Michigan11, University of Toronto12, University of Chile13, University of Chicago14, Stanford University15, University of KwaZulu-Natal16, University of California, Berkeley17, University of Cambridge18, Pontifical Catholic University of Chile19, Goddard Space Flight Center20, Lawrence Berkeley National Laboratory21, Florida State University22, University of Southern California23, University of Arizona24, University of Pittsburgh25, Stony Brook University26, Columbia University27, Rutgers University28, Université Paris-Saclay29, Perimeter Institute for Theoretical Physics30, University of Illinois at Urbana–Champaign31, University of Milan32, Haverford College33, California Institute of Technology34, McGill University35, Pontifical Catholic University of Valparaíso36, West Chester University of Pennsylvania37, Carnegie Mellon University38, Arizona State University39
TL;DR: In this article, 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 were presented.
Abstract: 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 $\ell=4000$. At large angular scales, foreground emission at 150 GHz is $\sim$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 $\Lambda$CDM for the ACT data alone with a prior on the optical depth of $\tau=0.065\pm0.015$. $\Lambda$CDM is a good fit. The best-fit model has a reduced $\chi^2$ of 1.07 (PTE=0.07) with $H_0=67.9\pm1.5$ km/s/Mpc. We show that the lensing BB signal is consistent with $\Lambda$CDM and limit the celestial EB polarization angle to $\psi_P =-0.09^{\circ}\pm0.09^{\circ}$. 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.
97 citations
TL;DR: LiteBIRD as discussed by the authors is a large-scale transition-edge sensors (TES) mission with a total wide frequency coverage between 34GHz and 448GHz, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket, which will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and high-frequency telescopes.
Abstract: Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite CMB polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the cosmic microwave background (CMB) by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34GHz and 448GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy's foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5Kelvin for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun-Earth Lagrangian point, L2, are planned for three years. An international collaboration between Japan, USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science (ISAS), JAXA selected LiteBIRD as the strategic large mission No. 2.
79 citations
TL;DR: In this paper, the authors describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS), and 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.
Abstract: We describe the observations and resultant galaxy cluster catalog from the 2770 deg2 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 follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ ≥ 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 we 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-SZ mass (l - 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 4σ level-with the relations intersecting at λ = 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.
72 citations
Case Western Reserve University1, University of Colorado Boulder2, University of Melbourne3, Argonne National Laboratory4, Cardiff University5, Fermilab6, National Institute of Standards and Technology7, University of California, Berkeley8, University of Chicago9, McGill University10, University of KwaZulu-Natal11, California Institute of Technology12, Lawrence Berkeley National Laboratory13, Canadian Institute for Advanced Research14, Harvey Mudd College15, European Southern Observatory16, University of Illinois at Urbana–Champaign17, Stanford University18, University of California, Davis19, University of Michigan20, University of Toronto21, University of Minnesota22, Yale University23, School of the Art Institute of Chicago24, Harvard University25, University of Maryland, College Park26, National Center for Supercomputing Applications27, University of California, Los Angeles28
TL;DR: In this article, the authors report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope.
Abstract: We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg2 of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: 52 320.
69 citations
TL;DR: LiteBIRD as discussed by the authors is a large-scale transition-edge sensor system for future satellite cosmic microwave background (CMB) polarization experiments, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket.
Abstract: Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite cosmic microwave background (CMB) polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA’s H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the CMB by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34 and 448 GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy’s foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5 K for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun–Earth Lagrangian point, L2, are planned for 3 years. An international collaboration between Japan, the USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science, JAXA, selected LiteBIRD as the strategic large mission No. 2.
60 citations
University of Melbourne1, Cardiff University2, Fermilab3, National Institute of Standards and Technology4, University of Colorado Boulder5, University of California, Berkeley6, University of Hawaii7, Argonne National Laboratory8, University of Chicago9, McGill University10, University of KwaZulu-Natal11, California Institute of Technology12, Lawrence Berkeley National Laboratory13, Canadian Institute for Advanced Research14, Harvey Mudd College15, European Southern Observatory16, University of Illinois at Urbana–Champaign17, Stanford University18, University of California, Davis19, Institut d'Astrophysique de Paris20, University of Michigan21, University of Toronto22, University of Minnesota23, Case Western Reserve University24, Yale University25, School of the Art Institute of Chicago26, Harvard University27, University of Maryland, College Park28, National Center for Supercomputing Applications29, University of California, Los Angeles30
TL;DR: In this article, a search for anisotropic cosmic birefringence in the southern sky at 150 GHz with the SPTpol camera on the South Pole Telescope is presented.
Abstract: We present a search for anisotropic cosmic birefringence in 500 deg2 of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) E and B fields. We then measure the angular power spectrum of this map, which is found to be consistent with zero. The nondetection is translated into an upper limit on the amplitude of the scale-invariant cosmic rotation power spectrum, L(L+1)CααL/2π<0.10×10−4 rad2 (0.033 deg2, 95% C.L.). This upper limit can be used to place constraints on the strength of primordial magnetic fields, B1 Mpc<17 nG (95% C.L.), and on the coupling constant of the Chern-Simons electromagnetic term gaγ<4.0×10−2/HI (95% C.L.), where HI is the inflationary Hubble scale. For the first time, we also cross-correlate the CMB temperature fluctuations with the reconstructed rotation angle map, a signal expected to be nonvanishing in certain theoretical scenarios, and find no detectable signal. We perform a suite of systematics and consistency checks and find no evidence for contamination.
56 citations
University of Melbourne1, Cardiff University2, Fermilab3, University of Colorado Boulder4, National Institute of Standards and Technology5, University of California, Berkeley6, Argonne National Laboratory7, University of Chicago8, McGill University9, University of KwaZulu-Natal10, California Institute of Technology11, Lawrence Berkeley National Laboratory12, Canadian Institute for Advanced Research13, Harvey Mudd College14, European Southern Observatory15, University of Illinois at Urbana–Champaign16, Stanford University17, University of California, Davis18, University of Paris19, University of Michigan20, University of Toronto21, Case Western Reserve University22, Yale University23, School of the Art Institute of Chicago24, Harvard University25, University of Maryland, College Park26, University of California, Los Angeles27
TL;DR: In this article, the cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg2 SPTpol survey were presented.
Abstract: We present cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg2 SPTpol survey, the most precise CMB lensing measurement from the ground to date. We fit a flat ΛCDM model to the reconstructed lensing power spectrum alone and in addition with other data sets: baryon acoustic oscillations (BAO), as well as primary CMB spectra from Planck and SPTpol. The cosmological constraints based on SPTpol and Planck lensing band powers are in good agreement when analyzed alone and in combination with Planck full-sky primary CMB data. With weak priors on the baryon density and other parameters, the SPTpol CMB lensing data alone provide a 4% constraint on ${\sigma }_{8}{{\rm{\Omega }}}_{m}^{0.25}=0.593\pm 0.025$. Jointly fitting with BAO data, we find ${\sigma }_{8}=0.779\pm 0.023$, ${{\rm{\Omega }}}_{m}={0.368}_{-0.037}^{+0.032}$, and ${H}_{0}={72.0}_{-2.5}^{+2.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$, up to $2\sigma $ away from the central values preferred by Planck lensing + BAO. However, we recover good agreement between SPTpol and Planck when restricting the analysis to similar scales. We also consider single-parameter extensions to the flat ΛCDM model. The SPTpol lensing spectrum constrains the spatial curvature to be ${{\rm{\Omega }}}_{K}=-0.0007\pm 0.0025$ and the sum of the neutrino masses to be $\sum {m}_{
u }\lt 0.23$ eV at 95% C.L. (with Planck primary CMB and BAO data), in good agreement with the Planck lensing results. With the differences in the signal-to-noise ratio of the lensing modes and the angular scales covered in the lensing spectra, this analysis represents an important independent check on the full-sky Planck lensing measurement.
50 citations
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 two 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 z ≥ 1.0, with a maximum confirmed redshift of ${z}_{\max }=1.38\pm 0.10$. We expect this catalog to contain every galaxy cluster with ${M}_{500c}\gt 2.6\times {10}^{14}{M}_{\odot }{{h}}_{70}^{-1}$ 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 ${M}_{500c}=2.7\times {10}^{14}{M}_{\odot }{{h}}_{70}^{-1}$. Compared to previous SPT works, the increased depth of the millimeter-wave data (11.2 and 6.5 μK-arcmin at 95 and 150 GHz, respectively) makes it possible to find more galaxy clusters at high redshift and lower mass.
TL;DR: The CONCERTO project as mentioned in this paper proposed a low-resolution spectrometer based on the lumped element kinetic inductance detectors (LEKID) technology, which is used for line intensity mapping (LIM).
Abstract: Context. Characterising the large-scale structure in the Universe from present times to the high redshift epoch of reionisation is essential to constraining the cosmology, the history of star formation, and reionisation, to measuring the gas content of the Universe, and to obtaining a better understanding of the physical processes that drive galaxy formation and evolution. Using the integrated emission from unresolved galaxies or gas clouds, line intensity mapping (LIM) provides a new observational window to measure the larger properties of structures. This very promising technique motivates the community to plan for LIM experiments. Aims. We describe the development of a large field-of-view instrument, named CONCERTO (for CarbON CII line in post-rEionisation and ReionisaTiOn epoch), operating in the range 130–310 GHz from the APEX 12-m telescope (5100 m above sea level). CONCERTO is a low-resolution spectrometer based on the lumped element kinetic inductance detectors (LEKID) technology. Spectra are obtained using a fast Fourier transform spectrometer (FTS), coupled to a dilution cryostat with a base temperature of 0.1 K. Two two kilo-pixel arrays of LEKID are mounted inside the cryostat that also contains the cold optics and the front-end electronics. Methods. We present, in detail, the technological choices leading to the instrumental concept, together with the design and fabrication of the instrument and preliminary laboratory tests on the detectors. We also give our best estimates for CONCERTO sensitivity and give predictions for two of the main scientific goals of CONCERTO, that is, a [CII]-intensity mapping survey and observations of galaxy clusters. Results. We provide a detailed description of the instrument design. Based on realistic comparisons with existing instruments developed by our group (NIKA, NIKA2, and KISS), and on the laboratory characterisation of our detectors, we provide an estimate for CONCERTO sensitivity on the sky. Finally, we describe, in detail, two of the main scientific goals offered by CONCERTO at APEX. Key words: instrumentation: detectors / instrumentation: spectrographs / telescopes / cosmology: observations © The CONCERTO collaboration 2020
TL;DR: In this article, the authors present the calibration method and the performance assessment of NIKA2 after one year of observation, using a large data set acquired between January 2017 and February 2018 including observations of primary and secondary calibrators and faint sources.
Abstract: Context. NIKA2 is a dual-band millimetre continuum camera of 2 900 kinetic inductance detectors, operating at 150 and 260 GHz, installed at the IRAM 30-m telescope in Spain. Open to the scientific community since October 2017, NIKA2 will provide key observations for the next decade to address a wide range of open questions in astrophysics and cosmology. Aims. Our aim is to present the calibration method and the performance assessment of NIKA2 after one year of observation. Methods. We used a large data set acquired between January 2017 and February 2018 including observations of primary and secondary calibrators and faint sources that span the whole range of observing elevations and atmospheric conditions encountered by the IRAM 30-m telescope. This allowed us to test the stability of the performance parameters against time evolution and observing conditions. We describe a standard calibration method, referred to as the “Baseline” method, to translate raw data into flux density measurements. This includes the determination of the detector positions in the sky, the selection of the detectors, the measurement of the beam pattern, the estimation of the atmospheric opacity, the calibration of absolute flux density scale, the flat fielding, and the photometry. We assessed the robustness of the performance results using the Baseline method against systematic effects by comparing results using alternative methods. Results. We report an instantaneous field of view of 6.5′ in diameter, filled with an average fraction of 84%, and 90% of valid detectors at 150 and 260 GHz, respectively. The beam pattern is characterised by a FWHM of 17.6″ ± 0.1″ and 11.1″ ± 0.2″, and a main-beam efficiency of 47%±3%, and 64%±3% at 150 and 260 GHz, respectively. The point-source rms calibration uncertainties are about 3% at 150 GHz and 6% at 260 GHz. This demonstrates the accuracy of the methods that we deployed to correct for atmospheric attenuation. The absolute calibration uncertainties are of 5%, and the systematic calibration uncertainties evaluated at the IRAM 30-m reference Winter observing conditions are below 1% in both channels. The noise equivalent flux density at 150 and 260 GHz are of 9 ± 1 mJy s1/2 and 30 ± 3 mJy s1/2. This state-of-the-art performance confers NIKA2 with mapping speeds of 1388 ± 174 and 111 ± 11 arcmin2 mJy−2 h−1 at 150 and 260 GHz. Conclusions. With these unique capabilities of fast dual-band mapping at high (better that 18″) angular resolution, NIKA2 is providing an unprecedented view of the millimetre Universe.
13 Dec 2020
TL;DR: TolTEC as discussed by the authors is a three-band imaging polarimeter for the Large Millimeter Telescope (LMT) with diffraction-limited beams with FWHM of 5, 7, and 11 arcsec.
Abstract: TolTEC is a three-band imaging polarimeter for the Large Millimeter Telescope. Simultaneously observing with passbands at 1.1mm, 1.4mm and 2.0mm, TolTEC has diffraction-limited beams with FWHM of 5, 7, and 11 arcsec, respectively. Over the coming decade, TolTEC will perform a combination of PI-led and Open-access Legacy Survey projects. Herein we provide an overview of the instrument and give the first quantitative measures of its performance in the lab prior to shipping to the telescope in 2021.
TL;DR: The Large Scale Polarization Explorer (LSPE) is a cosmology program for the measurement of large scale curl-like features (B-modes) in the polarization of the Cosmic Microwave Background.
Abstract: The Large Scale Polarization Explorer (LSPE) is a cosmology program for the measurement of large scale curl-like features (B-modes) in the polarization of the Cosmic Microwave Background. Its goal is to constrain the background of inflationary gravity waves traveling through the universe at the time of matter-radiation decoupling. The two instruments of LSPE are meant to synergically operate by covering a large portion of the northern microwave sky. LSPE/STRIP is a coherent array of receivers planned to be operated from the Teide Observatory in Tenerife, for the control and characterization of the low-frequency polarized signals of galactic origin; LSPE/SWIPE is a balloon-borne bolometric polarimeter based on 330 large throughput multi-moded detectors, designed to measure the CMB polarization at 150 GHz and to monitor the polarized emission by galactic dust above 200 GHz. The combined performance and the expected level of systematics mitigation will allow LSPE to constrain primordial B-modes down to a tensor/scalar ratio of $10^{-2}$. We here report the status of the STRIP pre-commissioning phase and the progress in the characterization of the key subsystems of the SWIPE payload (namely the cryogenic polarization modulation unit and the multi-moded TES pixels) prior to receiver integration.
TL;DR: In this paper, the in-flight performance of the horn-coupled lumped element kinetic inductance detector arrays of the balloon-borne OLIMPO experiment is described, and the results can be considered the first step of KID technology validation in a representative space environment.
Abstract: We describe the in-flight performance of the horn-coupled lumped element kinetic inductance detector arrays of the balloon-borne OLIMPO experiment. These arrays have been designed to match the spectral bands of OLIMPO: 150, 250, 350, and 460GHz, and they have been operated at 0.3K and at an altitude of 37.8km during the stratospheric flight of the OLIMPO payload, in Summer 2018. During the first hours of flight, we tuned the detectors and verified their large dynamics under the radiative background variations due to elevation increase of the telescope and to the insertion of the plug-in room-temperature differential Fourier transform spectrometer into the optical chain. We have found that the detector noise equivalent powers are close to be photon noise limited and lower than those measured on the ground. Moreover, the data contamination due to primary cosmic rays hitting the arrays is less than 3% for all the pixels of all the arrays and less than 1% for most of the pixels. These results can be considered the first step of KID technology validation in a representative space environment.
TL;DR: The large-scale polarization explorer (LSPE) is a cosmology program for the measurement of large scale curl-like features (B-modes) in the polarization of the cosmic microwave background.
Abstract: The large-scale polarization explorer (LSPE) is a cosmology program for the measurement of large-scale curl-like features (B-modes) in the polarization of the cosmic microwave background. Its goal is to constrain the background of inflationary gravity waves traveling through the universe at the time of matter-radiation decoupling. The two instruments of LSPE are meant to synergically operate by covering a large portion of the northern microwave sky. LSPE/STRIP is a coherent array of receivers planned to be operated from the Teide Observatory in Tenerife, for the control and characterization of the low-frequency polarized signals of galactic origin; LSPE/SWIPE is a balloon-borne bolometric polarimeter based on 330 large throughput multi-moded detectors, designed to measure the CMB polarization at 150 GHz and to monitor the polarized emission by galactic dust above 200 GHz. The combined performance and the expected level of systematics mitigation will allow LSPE to constrain primordial B-modes down to a tensor/scalar ratio of
10
−2
10−2
. We here report the status of the STRIP pre-commissioning phase and the progress in the characterization of the key subsystems of the SWIPE payload (namely the cryogenic polarization modulation unit and the multi-moded TES pixels) prior to receiver integration.
SLAC National Accelerator Laboratory1, Stanford University2, Harvard University3, National Institute of Standards and Technology4, University of British Columbia5, University of Illinois at Urbana–Champaign6, University of Minnesota7, Cardiff University8, California Institute of Technology9, University of Cincinnati10, University of Cambridge11, Brookhaven National Laboratory12
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.
Massachusetts Institute of Technology1, University of Missouri2, École Polytechnique3, Cardiff University4, Paris Diderot University5, University of Grenoble6, University of Paris-Sud7, Sapienza University of Rome8, California Institute of Technology9, Spanish National Research Council10, University of Florida11, Aix-Marseille University12, PSL Research University13, Arizona State University14, University of Toulouse15, Institut d'Astrophysique de Paris16, University of California, Davis17
TL;DR: In this article, the authors presented the results of a multi-wavelength analysis of the very massive cluster MOO J1142+1527 at a redshift z = 1.2 discovered as part of the Massive and Distant Clusters of WISE Survey.
Abstract: The characterization of the Intracluster Medium (ICM) properties of high-redshift galaxy clusters is fundamental to our understanding of large-scale structure formation processes. We present the results of a multiwavelength analysis of the very massive cluster MOO J1142+1527 at a redshift z = 1.2 discovered as part of the Massive and Distant Clusters of WISE Survey. This analysis is based on high angular resolution Chandra X-ray and NIKA2 Sunyaev–Zel'dovich (SZ) data. The cluster thermodynamic radial profiles have been obtained with unprecedented precision at this redshift and up to 0.7R 500, thanks to the combination of high-resolution X-ray and SZ data. The comparison between the galaxy distribution mapped in infrared by Spitzer and the morphological properties of the ICM derived from the combined analysis of the Chandra and NIKA2 data leads us to the conclusion that the cluster is an ongoing merger. We have estimated a systematic uncertainty on the cluster total mass that characterizes both the impact of the observed deviations from spherical symmetry and of the core dynamics on the mass profile. We further combine the X-ray and SZ data at the pixel level to obtain maps of the temperature and entropy distributions. We find a relatively low-entropy core at the position of the X-ray peak and high-temperature regions located on its south and west sides. This work demonstrates that the addition of spatially resolved SZ observations to low signal-to-noise X-ray data brings a high information gain on the characterization of the evolution of ICM thermodynamic properties at z > 1.
Goddard Space Flight Center1, Cardiff University2, Johns Hopkins University3, University of Maryland, College Park4, Canadian Institute for Advanced Research5, University of Chicago6, Arizona State University7, University of Michigan8, University of Wisconsin-Madison9, New York University10, University of Toledo11
TL;DR: The Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a balloon-borne far-infrared telescope that will survey galactic formation history over cosmological time scales with redshifts between 0 and 3.5 as mentioned in this paper.
Abstract: The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a balloon-borne far-infrared telescope that will survey galactic formation history over cosmological time scales with redshifts between 0 and 3.5. EXCLAIM will measure the statistics of brightness fluctuations of redshifted cumulative carbon monoxide and singly ionized carbon line emissions, following an intensity mapping approach. EXCLAIM will couple all-cryogenic optical elements to six μ-Spec spectrometer modules, operating at 420-540 GHz with a spectral resolution of 512 and featuring microwave kinetic inductance detectors. Here, we present an overview of the mission and its development status.
Institute for the Physics and Mathematics of the Universe1, Kyoto University2, Cardiff University3, University of Chile4, KEK5, Graduate University for Advanced Studies6, University of California, San Diego7, International School for Advanced Studies8, University of New Mexico9, Paris Diderot University10, University of California, Berkeley11, University of Melbourne12, Lawrence Berkeley National Laboratory13, University of Sussex14, Dalhousie University15, University of Tokyo16, Stanford University17, McGill University18, Pontifical Catholic University of Chile19, York University20, University of Illinois at Urbana–Champaign21, Yokohama National University22, University of Minnesota23, University of Colorado Boulder24, Tohoku University25, National Central University26, Intel27
TL;DR: Polarbear-2A is the first receiver in the Simons array, a cosmic microwave background experiment located on the Atacama Plateau in Chile as discussed by the authors, which achieved the first light in January 2019 by mapping the microwave emission from planet observations.
Abstract: Polarbear-2A is the first of three receivers in the Simons array, a cosmic microwave background experiment located on the Atacama Plateau in Chile. Polarbear-2A was deployed and achieved the first light in January 2019 by mapping the microwave emission from planet observations. Commissioning work is underway to prepare the receiver for science observations.
California Institute of Technology1, Cardiff University2, Stanford University3, University of British Columbia4, Harvard University5, University of Cincinnati6, University of Minnesota7, University of Illinois at Urbana–Champaign8, National Institute of Standards and Technology9, Brookhaven National Laboratory10
TL;DR: The BICEP/Keck (BK) experiment targets this primordial signature, the amplitude of which is parameterized by the tensor-to-scalar ratio r, by observing the polarized microwave sky through the exceptionally clean and stable atmosphere at the South Pole as discussed by the authors.
Abstract: Branches of cosmic inflationary models, such as slow-roll inflation, predict a background of primordial gravitational waves that imprints a unique odd-parity “B-mode” pattern in the Cosmic Microwave Background (CMB) at amplitudes that are within experimental reach. The BICEP/Keck (BK) experiment targets this primordial signature, the amplitude of which is parameterized by the tensor-to-scalar ratio r, by observing the polarized microwave sky through the exceptionally clean and stable atmosphere at the South Pole. B-mode measurements require an instrument with exquisite sensitivity, tight control of systematics, and wide frequency coverage to disentangle the primordial signal from the Galactic foregrounds. BICEP Array represents the most recent stage of the BK program and comprises four BICEP3-class receivers observing at 30/40, 95, 150 and 220/270 GHz. The 30/40 GHz receiver will be deployed at the South Pole during the 2019/2020 austral summer. After 3 full years of observations with 30,000+ detectors, BICEP Array will measure primordial gravitational waves to a precision σ(r) between 0.002 and 0.004, depending on foreground complexity and the degree of lensing removal. In this paper, we give an overview of the instrument, highlighting the design features in terms of cryogenics, magnetic shielding, detectors and readout architecture as well as reporting on the integration and tests that are ongoing with the first receiver at 30/40 GHz.
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TL;DR: In this article, a fast rotating half-wave plate (HWP) was used to obtain a large diameter of 250 mm for the NIKA and NIKa2 cameras.
Abstract: CONTEXT.Large field-of-view imaging/polarimetry instruments operating at millimeter and submm wavelengths are fundamental tools to understand the role of magnetic fields (MF) in channeling filament material into prestellar cores providing a unique insight in the physics of galactic star-forming regions. Among other topics, at extra-galactic scales, polarization observations of AGNs will allow us to constrain the possible physical conditions of the emitting plasma from the jets and/or exploring the physics of dust inside supernova remnants. The kilo-pixel NIKA2 camera, installed at the IRAM 30-m telescope, represents today one of the best tools available to the astronomers to produce simultaneous intensity/polarimetry maps over large fields at 260 GHz (1.15 mm). AIMS.The polarization measurement, in NIKA and NIKA2, is achieved by rapidly modulating the total incoming polarization. This allows in the end to safely isolate the small science signal from the large, un-polarized and strongly variable, atmospheric background. METHODS.The polarization modulation is achieved by inserting a fast rotating Half-Wave Plate (HWP) in the optical beam. In order to allow wide field-of-view observations, the plate has to be large, with a diameter exceeding 250 mm. The modulation of the polarized signal, at 12 Hz, requires also the waveplate to be sufficiently light. In addition, this key optical element has to exhibit optimal electromagnetic characteristics in terms of transmission and differential phase-shift. For this purpose, three metamaterial HWPs have been developed using the mesh-filter technology. The knowledge acquired in developing the first two single-band HWPs was used to achieve the more challenging performance requirements of the last dual-band HWP. The first and the third waveplates met the requirements for both the NIKA and NIKA2 instruments. RESULTS.(abridged)
University of Chicago1, Argonne National Laboratory2, 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 South Pole Telescope 3G readout as measured on-sky, showing that low-frequency noise in the readout will not limit 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 ∼
∼
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.
TL;DR: A novel design for an FPI in which the wavelength is tuned by scanning the angle of incidence on a high refractive index etalon is presented, which simplifies the cryomechanical design, actuation, and metrology.
Abstract: The sensitivity of state-of-the-art superconducting far-infrared detectors used in conjunction with cryogenically cooled space telescopes and instrumentation is such that spectroscopic observations are generally limited by photon noise from the astronomical source or by galactic foreground or zodiacal emission within the field-of-view. Therefore, an instrument design that restricts the spectral bandpass viewed by the detector must be employed. One method of achieving background limited, high resolution spectroscopy is to combine a high resolution component such as a Fabry-Perot interferometer (FPI) with a lower resolution, post-dispersing system, such as a grating spectrometer, the latter serving to restrict the spectral bandpass. The resonant wavelength of an FPI is most often tuned by changing the spacing or medium between the parallel reflecting plates of the etalon. In this paper, we present a novel design for an FPI in which the wavelength is tuned by scanning the angle of incidence on a high refractive index etalon. This concept simplifies the cryomechanical design, actuation, and metrology. The first results from the realized instrument are presented and compared with theory. The effects on the spectral response as a function of the incident angle have been simulated and shown to agree well with the observation.
TL;DR: LiteBIRD as discussed by the authors is a JAXA-led mission designed to search for the existence of the primordial gravitational waves produced during the inflationary phase of the Universe, through the measurements of their imprint onto the polarization of the cosmic microwave background (CMB).
Abstract: LiteBIRD is a JAXA-led Strategic Large-Class mission designed to search for the existence of the primordial gravitational waves produced during the inflationary phase of the Universe, through the measurements of their imprint onto the polarization of the cosmic microwave background (CMB). These measurements, requiring unprecedented sensitivity, will be performed over the full sky, at large angular scales, and over 15 frequency bands from 34 GHz to 448 GHz. The LiteBIRD instruments consist of three telescopes, namely the Low-, Medium-and High-Frequency Telescope (respectively LFT, MFT and HFT). We present in this paper an overview of the design of the Medium-Frequency Telescope (89{224 GHz) and the High-Frequency Telescope (166{448 GHz), the so-called MHFT, under European responsibility, which are two cryogenic refractive telescopes cooled down to 5 K. They include a continuous rotating half-wave plate as the first optical element, two high-density polyethylene (HDPE) lenses and more than three thousand transition-edge sensor (TES) detectors cooled to 100 mK. We provide an overview of the concept design and the remaining specific challenges that we have to face in order to achieve the scientific goals of LiteBIRD.
28 May 2020
TL;DR: OLIMPO as mentioned in this paper is a balloon-borne experiment aiming at spectroscopic measurements of the Sunyaev-Zel'dovich effect in clusters of galaxies, using a 2.6m aperture telescope, a differential Fourier transform spectrometer and four arrays of lumped element kinetic inductance detectors operating at the temperature of 0.3 K. The payload was launched from Longyearbyen airport (Svalbard Islands) on July 14th, 2018, and operated for 5 days, at an altitude of 38 km around the North Pole.
Abstract: OLIMPO is a balloon-borne experiment aiming at spectroscopic measurements of the Sunyaev-Zel'dovich effect in clusters of galaxies. The instrument operates from the stratosphere, so that it can cover a wide frequency range (from ~ 130 to ~ 520 GHz in 4 bands), including frequencies which are not observable with ground-based instruments. OLIMPO is composed of a 2.6-m aperture telescope, a differential Fourier transform spectrometer and four arrays of lumped element kinetic inductance detectors operating at the temperature of 0.3 K. The payload was launched from the Longyearbyen airport (Svalbard Islands) on July 14th, 2018, and operated for 5 days, at an altitude of 38 km around the North Pole. We report the in-flight performance of the first lumped element kinetic inductance detector arrays ever flown onboard a stratospheric balloon.
TL;DR: In this paper, the authors describe the design and in-flight performance of the cryostat and the self-contained refrigerator for the OLIMPO balloon-borne experiment, a spectrophotometer to measure the Sunyaev-Zel-dovich effect in clusters of galaxies.
Paris Diderot University1, École Polytechnique2, Cardiff University3, University of Grenoble4, University of Paris-Sud5, 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, Kagoshima University13
TL;DR: In this article, the authors present a preliminary analysis of the leakage pattern and its dependence with elevation, and also present the current leakage correction made possible by the NIKA2 pipeline in polarization mode.
Abstract: Clarifying the role of magnetic fields in the star formation process is crucial. Observations have already shown that magnetic fields play an important role in the early stages of star formation. The high spatial resolution (∼0.01 to 0.05 pc) provided by NIKA2-Pol 1.2 mm imaging polarimetry of nearby clouds will help us clarify the geometry of the B-field within dense cores and molecular filaments as part of the IRAM 30m large program B-FUN. There are numerous challenging issues in the validation of NIKA2-Pol such as the calibration of instrumental polarization. The commissioning phase of NIKA2-Pol is underway and is helping us characterize the intensity-to-polarization “leakage” pattern of the instrument. We present a preliminary analysis of the leakage pattern and its dependence with elevation. We also present the current leakage correction made possible by the NIKA2 pipeline in polarization mode based on the NIKA2-Pol commissioning data taken in December 2018. Based on reduced Stokes I, Q, U data we find that the leakage pattern of NIKA2-Pol depends on elevation and is sensitive to the focus of the telescope.
Goddard Space Flight Center1, University of Wisconsin-Madison2, Cardiff University3, Lawrence Berkeley National Laboratory4, University of Maryland, College Park5, National Institute of Standards and Technology6, University of Chicago7, Arizona State University8, New York University9, Rutgers University10, University of Toledo11
TL;DR: The EXPERiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a balloon-borne telescope that will measure integrated line emission from carbon monoxide (CO) at redshifts z < 1 and ionized carbon ([CII]) at redshift z = 2.5-3.5 to probe star formation over cosmic time in cross-correlation with galaxy redshift surveys as mentioned in this paper.
Abstract: This work describes the optical design of the EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM). EXCLAIM is a balloon-borne telescope that will measure integrated line emission from carbon monoxide (CO) at redshifts z<1 and ionized carbon ([CII]) at redshifts z = 2.5-3.5 to probe star formation over cosmic time in cross-correlation with galaxy redshift surveys. The EXCLAIM instrument will observe at frequencies of 420--540 GHz using six microfabricated silicon integrated spectrometers with spectral resolving power R = 512 coupled to kinetic inductance detectors (KIDs). A completely cryogenic telescope cooled to a temperature below 5 K provides low-background observations between narrow atmospheric lines in the stratosphere. Off-axis reflective optics use a 90-cm primary mirror to provide 4.2' full-width at half-maximum (FWHM) resolution at the center of the EXCLAIM band over a field of view of 22.5'.