Showing papers by "S. S. Meyer published in 2020"
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
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TL;DR: The Probe of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from space with sensitivity over the full celestial sky as discussed by the authors.
Abstract: The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from space with sensitivity over the full celestial sky. POEMMA will observe the extensive air showers (EASs) from UHECRs and UHE neutrinos above 20 EeV via air fluorescence. Additionally, POEMMA will observe the Cherenkov signal from upward-moving EASs induced by Earth-interacting tau neutrinos above 20 PeV. The POEMMA spacecraft are designed to quickly re-orientate to follow up transient neutrino sources and obtain unparalleled neutrino flux sensitivity. Developed as a NASA Astrophysics Probe-class mission, POEMMA consists of two identical satellites flying in loose formation in 525 km altitude orbits. Each POEMMA instrument incorporates a wide field-of-view (45$^\circ$) Schmidt telescope with over 6 m$^2$ of collecting area. The hybrid focal surface of each telescope includes a fast (1~$\mu$s) near-ultraviolet camera for EAS fluorescence observations and an ultrafast (10~ns) optical camera for Cherenkov EAS observations. In a 5-year mission, POEMMA will provide measurements that open new multi-messenger windows onto the most energetic events in the universe, enabling the study of new astrophysics and particle physics at these otherwise inaccessible energies.
64 citations
University of Melbourne1, Cardiff University2, Fermilab3, University of Colorado Boulder4, National Institute of Standards and Technology5, University of California, Berkeley6, University of Hawaii7, Argonne National Laboratory8, University of Chicago9, University of KwaZulu-Natal10, McGill University11, 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, University of KwaZulu-Natal9, McGill University10, 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, University of KwaZulu-Natal12, McGill University13, 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.
46 citations
University of Colorado Boulder1, University of California, Santa Barbara2, University of Illinois at Urbana–Champaign3, University of Chicago4, Diego Portales University5, National Institute of Standards and Technology6, Fermilab7, Argonne National Laboratory8, Dalhousie University9, University of Cambridge10, California Institute of Technology11, Lawrence Berkeley National Laboratory12, University of California, Berkeley13, McGill University14, Canadian Institute for Advanced Research15, European Southern Observatory16, University of California, Davis17, University of Michigan18, University of Oslo19, Ludwig Maximilian University of Munich20, Max Planck Society21, University of Minnesota22, University of Melbourne23, Case Western Reserve University24, School of the Art Institute of Chicago25, University of Texas at Austin26, Harvard University27, Stanford University28, Goddard Space Flight Center29, University of Toronto30
TL;DR: In this article, the authors presented a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530 square degree area surveyed with the South Pole Telescope (SPT) from 2008-2011 in three bands centered at 95, 150, and 220 GHz.
Abstract: We present a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530 square degree area surveyed with the South Pole Telescope (SPT) from 2008–2011 in three bands centered at 95, 150, and 220 GHz. The catalog contains 4845 sources measured at a significance of 4.5σ or greater in at least one band, corresponding to detections above approximately 9.8, 5.8, and 20.4 mJy in 95, 150, and 220 GHz, respectively. The spectral behavior in the SPT bands is used for source classification into two populations based on the underlying physical mechanisms of compact, emissive sources that are bright at millimeter wavelengths: synchrotron radiation from active galactic nuclei and thermal emission from dust. The latter population includes a component of high-redshift sources often referred to as submillimeter galaxies (SMGs). In the relatively bright flux ranges probed by the survey, these sources are expected to be magnified by strong gravitational lensing. The survey also contains sources consistent with protoclusters, groups of dusty galaxies at high redshift undergoing collapse. We cross-match the SPT-SZ catalog with external catalogs at radio, infrared, and X-ray wavelengths and identify available redshift information. The catalog splits into 3980 synchrotron-dominated and 865 dust-dominated sources, and we determine a list of 506 SMGs. Ten sources in the catalog are identified as stars. We calculate number counts for the full catalog, and synchrotron and dusty components, using a bootstrap method and compare our measured counts with models. This paper represents the third and final catalog of point sources in the SPT-SZ survey.
38 citations
TL;DR: In this paper, the authors presented a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530-square-degree area surveyed with the South Pole Telescope (SPT) from 2008 - 2011 in three bands centered at 95, 150, and 220 GHz.
Abstract: We present a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530-square-degree area surveyed with the South Pole Telescope (SPT) from 2008 - 2011 in three bands centered at 95, 150, and 220 GHz. The catalog contains 4845 sources measured at a significance of 4.5 sigma or greater in at least one band, corresponding to detections above approximately 9.8, 5.8, and 20.4 mJy in 95, 150, and 220 GHz, respectively. Spectral behavior in the SPT bands is used for source classification into two populations based on the underlying physical mechanisms of compact, emissive sources that are bright at millimeter wavelengths: synchrotron radiation from active galactic nuclei and thermal emission from dust. The latter population includes a component of high-redshift sources often referred to as submillimeter galaxies (SMGs). In the relatively bright flux ranges probed by the survey, these sources are expected to be magnified by strong gravitational lensing. The survey also contains sources consistent with protoclusters, groups of dusty galaxies at high redshift undergoing collapse. We cross-match the SPT-SZ catalog with external catalogs at radio, infrared, and X-ray wavelengths and identify available redshift information. The catalog splits into 3980 synchrotron-dominated and 865 dust-dominated sources and we determine a list of 506 SMGs. Ten sources in the catalog are identified as stars. We calculate number counts for the full catalog, and synchrotron and dusty components, using a bootstrap method and compare our measured counts with models. This paper represents the third and final catalog of point sources in the SPT-SZ survey.
32 citations
University of Melbourne1, Cardiff University2, Fermilab3, National Institute of Standards and Technology4, University of Colorado Boulder5, University of California, Berkeley6, University of Pennsylvania7, 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, University of Michigan20, Max Planck Society21, University of Toronto22, Case Western Reserve University23, Yale University24, School of the Art Institute of Chicago25, Harvard University26, University of Maryland, College Park27, University of California, Los Angeles28
TL;DR: In this article, the authors reported new measurements of millimeter-wave power spectra in the angular multipole range (APM) of the angular scales of the SZ and SZ bispectrum.
Abstract: We report new measurements of millimeter-wave power spectra in the angular multipole range $2000 \le \ell \le 11,000$ (angular scales $5^\prime \gtrsim \theta \gtrsim 1^\prime$). By adding 95 and 150\,GHz data from the low-noise 500 deg$^2$ SPTpol survey to the SPT-SZ three-frequency 2540 deg$^2$ survey, we substantially reduce the uncertainties in these bands. These power spectra include contributions from the primary cosmic microwave background, cosmic infrared background, radio galaxies, and thermal and kinematic Sunyaev-Zel'dovich (SZ) effects. The data favor a thermal SZ (tSZ) power at 143\,GHz of $D^{\rm tSZ}_{3000} = 3.42 \pm 0.54~ \mu {\rm K}^2$ and a kinematic SZ (kSZ) power of $D^{\rm kSZ}_{3000} = 3.0 \pm 1.0~ \mu {\rm K}^2$. This is the first measurement of kSZ power at $\ge 3\,\sigma$. We study the implications of the measured kSZ power for the epoch of reionization, finding the duration of reionization to be $\Delta z_{re} = 1.0^{+1.6}_{-0.7}$ ($\Delta z_{re}< 4.1$ at 95% confidence), when combined with our previously published tSZ bispectrum measurement.
25 citations
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TL;DR: In this article, the first simultaneous Bayesian parameter inference and optimal reconstruction of the gravitational lensing of the cosmic microwave background (CMB), using 100 deg$^2$ of polarization observations from the SPT-pol receiver on the South Pole Telescope, was performed.
Abstract: We perform the first simultaneous Bayesian parameter inference and optimal reconstruction of the gravitational lensing of the cosmic microwave background (CMB), using 100 deg$^2$ of polarization observations from the SPTpol receiver on the South Pole Telescope. These data reach noise levels as low as 5.8 $\mu$K-arcmin in polarization, which are low enough that the typically used quadratic estimator (QE) technique for analyzing CMB lensing is significantly sub-optimal. Conversely, the Bayesian procedure extracts all lensing information from the data and is optimal at any noise level. We infer the amplitude of the gravitational lensing potential to be $A_\phi\,{=}\,0.949\,{\pm}\,0.122$ using the Bayesian pipeline, consistent with our QE pipeline result, but with 17\% smaller error bars. The Bayesian analysis also provides a simple way to account for systematic uncertainties, performing a similar job as frequentist "bias hardening," and reducing the systematic uncertainty on $A_\phi$ due to polarization calibration from almost half of the statistical error to effectively zero. Finally, we jointly constrain $A_\phi$ along with $A_{\rm L}$, the amplitude of lensing-like effects on the CMB power spectra, demonstrating that the Bayesian method can be used to easily infer parameters both from an optimal lensing reconstruction and from the delensed CMB, while exactly accounting for the correlation between the two. These results demonstrate the feasibility of the Bayesian approach on real data, and pave the way for future analysis of deep CMB polarization measurements with SPT-3G, Simons Observatory, and CMB-S4, where improvements relative to the QE can reach 1.5 times tighter constraints on $A_\phi$ and 7 times lower effective lensing reconstruction noise.
12 citations
University of Chicago1, Argonne National Laboratory2, Fermilab3, University of California, Berkeley4, Cardiff University5, Stanford University6, SLAC National Accelerator 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 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: In this paper, the angular correlation function of the cosmic microwave background temperature at large angular separation was analyzed based on published maps derived from Wilkinson Microwave Anisotropy Probe and Planck satellite data, using different models of astrophysical foregrounds.
Abstract: A new analysis is presented of the angular correlation function C(Θ) of cosmic microwave background temperature at large angular separation, based on published maps derived from Wilkinson Microwave Anisotropy Probe and Planck satellite data, using different models of astrophysical foregrounds. It is found that using a common analysis, the results from the two satellites are very similar. In particular, it is found that previously published differences between measured values of C(Θ) near Θ = 90° arise mainly from different choices of masks in regions of largest Galactic emissions, and that demonstrated measurement biases are reduced by eliminating masks altogether. Maps from both satellites are shown to agree with C(90°) = 0 to within estimated statistical and systematic errors, consistent with an exact symmetry predicted in a new holographic quantum model of inflation.
Fermilab1, University of Chicago2, 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 article, a transition-edge sensor (TES) wafer was replaced with a new wafer fabricated with Al-Mn TESs instead of the Ti/Au design originally deployed for SPT-3G.
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
∼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-laboratory 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.
University of Illinois at Urbana–Champaign1, University of Chicago2, Cardiff University3, Stanford University4, University of California, Berkeley5, Argonne National Laboratory6, University of Michigan7, McGill University8, Smithsonian Institution9, University of Colorado Boulder10, University of California, Los Angeles11, Case Western Reserve University12, Fermilab13, Lawrence Berkeley National Laboratory14, University of Toronto15
TL;DR: In this paper, the authors present two prescriptions for broadband (77 - 252 ε;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large format planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements.
Abstract: We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm 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 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.
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TL;DR: The Probe of Extreme Multi-Messenger Astrophysics (POEMMA) as discussed by the authors is designed to identify the sources of UHECRs and to observe cosmic neutrinos, both with full-sky coverage.
Abstract: The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to identify the sources of Ultra-High-Energy Cosmic Rays (UHECRs) and to observe cosmic neutrinos, both with full-sky coverage. Developed as a NASA Astrophysics Probe-class mission, POEMMA consists of two spacecraft flying in a loose formation at 525 km altitude, 28.5 deg inclination orbits. Each spacecraft hosts a Schmidt telescope with a large collecting area and wide field of view. A novel focal plane is optimized to observe both the UV fluorescence signal from extensive air showers (EASs) and the beamed optical Cherenkov signals from EASs. In POEMMA-stereo fluorescence mode, POEMMA will measure the spectrum, composition, and full-sky distribution of the UHECRs above 20 EeV with high statistics along with remarkable sensitivity to UHE neutrinos. The spacecraft are designed to quickly re-orient to a POEMMA-limb mode to observe neutrino emission from Target-of-Opportunity (ToO) transient astrophysical sources viewed just below the Earth's limb. In this mode, POEMMA will have unique sensitivity to cosmic neutrino tau events above 20 PeV by measuring the upward-moving EASs induced by the decay of the emerging tau leptons following the interactions of neutrino tau inside the Earth.
01 Feb 2020
TL;DR: In this article, the authors present the status of an on-going 1500 sq. deg. survey with the SPT-3G receiver, a new mm-wavelength camera on the 10m diameter South Pole Telescope (SPT).
Abstract: The cosmic microwave background (CMB) encodes information about the content and evolution of the universe. The presence of light, weakly interacting particles impacts the expansion history of the early universe, which alters the temperature and polarization anisotropies of the CMB. In this way, current measurements of the CMB place interesting constraints on the neutrino energy density and mass, as well as on the abundance of other possible light relativistic particle species. We present the status of an on-going 1500 sq. deg. survey with the SPT-3G receiver, a new mm-wavelength camera on the 10-m diameter South Pole Telescope (SPT). The SPT-3G camera consists of 16,000 superconducting transition edge sensors, a 10x increase over the previous generation camera, which allows it to map the CMB with an unprecedented combination of sensitivity and angular resolution. We highlight projected constraints on the abundance of sterile neutrinos and the sum of the neutrino masses for the SPT-3G survey, which could help determine the neutrino mass hierarchy.
TL;DR: The simulation and calibration of a Fourier transform spectrometer developed to measure the spectrum of radiation sources between 50 GHz and 330 GHz is presented and the comparison between simulations of a spectrally unresolved source and measurements by the FTS is presented.
Abstract: This paper presents the simulation and calibration of a Fourier transform spectrometer (FTS) developed to measure the spectrum of radiation sources between 50 GHz and 330 GHz, such as the cosmic microwave background. The recorded signal is modified from the ideal by properties of the interferometer and the detection system. We have developed a ray-trace-based simulation with which we can model these effects. The model can be verified with measurements and used to understand the instrument’s systematic effects and to design new optimized configurations. The optimization comprises parameters of the design, such as large etendu, maximal spectral resolution, compact size, operational simplicity, and light weight, that conflict and need to be balanced. The numerical simulation consists of two parts: time-stream signal analysis and a ray-trace-based simulation that includes polarization and path length calculations and can account for the effects of beam loss and change of focus as the delay-generating mirror travels on its path. The simulation can study the coherence level and frequency resolution of the FTS instrument. While not exercised in this study, the simulation also can be used to study the effect of mirror figure and polarizer non-idealities, walk-off rays in the beam due to the large etendu, as well as misalignment of optical elements. We then present the comparison between simulations of a spectrally unresolved source and measurements by the FTS.
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University of Alabama in Huntsville1, Colorado School of Mines2, Centre national de la recherche scientifique3, University of Tübingen4, Istituto Nazionale di Fisica Nucleare5, University of Turin6, Paris Diderot University7, École Polytechnique8, Marshall Space Flight Center9, University of Toulouse10, Karlsruhe Institute of Technology11, National Autonomous University of Mexico12, Università telematica internazionale UniNettuno13, City University of New York14, University of Rome Tor Vergata15
TL;DR: The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) instrument was launched out of Wanaka, New Zealand, by NASA in April, 2017 as a mission of opportunity as mentioned in this paper.
Abstract: The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) instrument was launched out of Wanaka, New Zealand, by NASA in April, 2017 as a mission of opportunity. The detector was developed as part of the Joint Experimental Missions for the Extreme Universe Space Observatory (JEM-EUSO) program toward a space-based ultra-high energy cosmic ray (UHECR) telescope with the main objective to make the first observation of UHECRs via the fluorescence technique from suborbital space. The EUSO-SPB1 instrument is a refractive telescope consisting of two 1m$^2$ Fresnel lenses with a high-speed UV camera at the focal plane. The camera has 2304 individual pixels capable of single photoelectron counting with a time resolution of 2.5$\mu$s. A detailed performance study including calibration was done on ground. We separately evaluated the properties of the Photo Detector Module (PDM) and the optical system in the laboratory. An end-to-end test of the instrument was performed during a field campaign in the West Desert in Utah, USA at the Telescope Array (TA) site in September 2016. The campaign lasted for 8 nights. In this article we present the results of the preflight laboratory and field tests. Based on the tests performed in the field, it was determined that EUSO-SPB1 has a field of view of 11.1$^\circ$ and an absolute photo-detection efficiency of 10%. We also measured the light flux necessary to obtain a 50% trigger efficiency using laser beams. These measurements were crucial for us to perform an accurate post flight event rate calculation to validate our cosmic ray search. Laser beams were also used to estimated the reconstruction angular resolution. Finally, we performed a flat field measurement in flight configuration at the launch site prior to the launch providing a uniformity of the focal surface better than 6%.