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Abstract Including millimeter-wave data in multiwavelength studies of the variability of active galactic nuclei (AGN) can provide insights into AGN physics that are not easily accessible at other wavelengths. We demonstrate in this work the potential of cosmic microwave background (CMB) telescopes to provide long-term, high-cadence millimeter-wave AGN monitoring over large fractions of sky. We report on a pilot study using data from the SPTpol instrument on the South Pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales. Between 2013 and 2016, SPTpol was used primarily to observe a single 500 deg2 field, covering the entire field several times per day with detectors sensitive to radiation in bands centered at 95 and 150 GHz. We use SPT 150 GHz observations to create AGN light curves, and we compare these millimeter-wave light curves to those at other wavelengths, in particular γ-ray and optical. In this Letter, we focus on a single source, PKS 2326-502, which has extensive, day-timescale monitoring data in gamma-ray, optical, and now millimeter-wave between 2013 and 2016. We find PKS 2326-502 to be in a flaring state in the first 2 yr of this monitoring, and we present a search for evidence of correlated variability between millimeter-wave, optical R-band, and γ-ray observations. This pilot study is paving the way for AGN monitoring with current and upcoming CMB experiments such as SPT-3G, Simons Observatory, and CMB-S4, including multiwavelength studies with facilities such as Vera C. Rubin Observatories Large Synoptic Survey Telescope.

We perform the first simultaneous Bayesian parameter inference and optimal reconstruction of the gravitational lensing of the cosmic microwave background (CMB), using 100 deg2 of polarization observations from the SPTpol receiver on the South Pole Telescope. These data reach noise levels as low as 5.8 µK arcmin in polarization, which are low enough that the typically used quadratic estimator (QE) technique for analyzing CMB lensing is significantly suboptimal. 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 f =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"or linear bias correction, and reducing the systematic uncertainty on A f due to polarization calibration from almost half of the statistical error to effectively zero. Finally, we jointly constrain A f along with A 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 f and seven times lower effective lensing reconstruction noise.

We present measurements of the average thermal Sunyaev Zel’dovich (tSZ) effect from optically selected galaxy groups and clusters at high signal-to-noise (up to ) and estimate their baryon content within a radius aperture. Sources from the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey DR15 catalog overlap with 3,700 sq deg of sky observed by the Atacama Cosmology Telescope (ACT) from 2008 to 2018 at 150 and 98 GHz (ACT DR5), and 2,089 sq deg of internal linear combination component-separated maps combining ACT and Planck data (ACT DR4). The corresponding optical depths , which depend on the baryon content of the halos, are estimated using results from cosmological hydrodynamic simulations assuming an active galactic nuclei feedback radiative cooling model. We estimate the mean mass of the halos in multiple luminosity bins, and compare the tSZ-based estimates to theoretical predictions of the baryon content for a Navarro-Frenk-White profile. We do the same for estimates extracted from fits to pairwise baryon momentum measurements of the kinematic Sunyaev-Zel’dovich effect (kSZ) for the same dataset obtained in a companion paper. We find that the estimates from the tSZ measurements in this work and the kSZ measurements in the companion paper agree within for two out of the three disjoint luminosity bins studied, while they differ by in the highest luminosity bin. The optical depth estimates account for one-third to all of the theoretically predicted baryon content in the halos across luminosity bins. Potential systematic uncertainties are discussed. The tSZ and kSZ measurements provide a step toward empirical Compton- relationships to provide new tests of cluster formation and evolution models.

We present a detection of the pairwise kinematic Sunyaev-Zeldovich (kSZ) effect using Atacama Cosmology Telescope (ACT) and Planck CMB observations in combination with Luminous Red Galaxy samples from the Sloan Digital Sky Survey (SDSS) DR15 catalog. Results are obtained using three ACT CMB maps: co-added 150 and 98 GHz maps, combining observations from 2008-2018 (ACT DR5), which overlap with SDSS DR15 over 3,700 sq. deg., and a component-separated map using night-time only observations from 2014-2015 (ACT DR4), overlapping with SDSS DR15 over 2,089 sq. deg. Comparisons of the results from these three maps provide consistency checks in relation to potential frequency-dependent foreground contamination. A total of 343,647 galaxies are used as tracers to identify and locate galaxy groups and clusters from which the kSZ signal is extracted using aperture photometry. We consider the impact of various aperture photometry assumptions and covariance estimation methods on the signal extraction. Theoretical predictions of the pairwise velocities are used to obtain best-fit, mass-averaged, optical depth estimates for each of five luminosity-selected tracer samples. A comparison of the kSZ-derived optical depth measurements obtained here to those derived from the thermal SZ effect for the same sample is presented in a companion paper.

Two recent large data releases for the Atacama Cosmology Telescope (ACT), called DR4 and DR5, are available for public access. These data include temperature and polarization maps that cover nearly half the sky at arcminute resolution in three frequency bands; lensing maps and component-separated maps covering ~2100 deg2 of sky; derived power spectra and cosmological likelihoods; a catalog of over 4000 galaxy clusters; and supporting ancillary products including beam functions and masks. The data and products are described in a suite of ACT papers; here we provide a summary. In order to facilitate ease of access to these data, we present a set of Jupyter IPython notebooks developed to introduce users to DR4, DR5, and the tools needed to analyze these data. The data products (excluding simulations) and the set of notebooks are publicly available on the NASA Legacy Archive for Microwave Background Data Analysis; simulation products are available on the National Energy Research Scientific Computing Center.

The thermal and kinematic Sunyaev-Zel'dovich effects (tSZ, kSZ) probe the thermodynamic properties of the circumgalactic and intracluster medium (CGM and ICM) of galaxies, groups, and clusters, since they are proportional, respectively, to the integrated electron pressure and momentum along the line of sight. We present constraints on the gas thermodynamics of CMASS (constant stellar mass) galaxies in the Baryon Oscillation Spectroscopic Survey using new measurements of the kSZ and tSZ signals obtained in a companion paper [Schaan et al.]. Combining kSZ and tSZ measurements, we measure within our model the amplitude of energy injection ϵM⋆c2, where M⋆ is the stellar mass, to be ϵ=(40±9)×10-6, and the amplitude of the nonthermal pressure profile to be αNth

The scattering of cosmic microwave background (CMB) photons off the free-electron gas in galaxies and clusters leaves detectable imprints on high resolution CMB maps: the thermal and kinematic Sunyaev-Zel'dovich effects (tSZ and kSZ respectively). We use combined microwave maps from the Atacama Cosmology Telescope DR5 and Planck in combination with the CMASS (mean redshift ⟨z

We present a catalog of 4195 optically confirmed Sunyaev–Zel’dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13,211 deg2 of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multifrequency matched filter to 98 and 150 GHz maps constructed from ACT observations obtained from 2008 to 2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04 < z < 1.91 (median z = 0.52). The catalog contains 222 z > 1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ signal versus mass-scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M500c > 3.8 × 1014 Me, evaluated at z = 0.5, for clusters detected at signal-to-noise ratio >5 in maps filtered at an angular scale of 2 4. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ signal mass-scaling relation, such as the Dark Energy Survey (4566 deg2), the Hyper Suprime-Cam Subaru Strategic Program (469 deg2), and the Kilo Degree Survey (825 deg2). We highlight some noteworthy objects in the sample, including potentially projected systems, clusters with strong lensing features, clusters with active central galaxies or star formation, and systems of multiple clusters that may be physically associated. The cluster catalog will be a useful resource for future cosmological analyses and studying the evolution of the intracluster medium and galaxies in massive clusters over the past 10 Gyr.

We present ΛCDM cosmological parameter constraints obtained from delensed microwave background power spectra. Lensing maps from a subset of DR4 data from the Atacama Cosmology Telescope (ACT) are used to undo the lensing effect in ACT spectra observed at 150 and 98 GHz. At 150 GHz, we remove the lensing distortion with an effective efficiency of 30% (TT), 30% (EE), 26% (TE) and 20% (BB); this results in detections of the delensing effect at 8.7σ (TT), 5.1σ (EE), 2.6σ (TE), and 2.4σ (BB) significance. The combination of 150 and 98 GHz TT, EE, and TE delensed spectra is well fit by a standard ΛCDM model. We also measure the shift in best-fit parameters when fitting delensed versus lensed spectra; while this shift does not inform our ability to measure cosmological parameters, it does provide a three-way consistency check among the lensing inferred from the best-fit parameters, the lensing in the CMB power spectrum, and the reconstructed lensing map. This shift is predicted to be zero when fitting with the correct model since both lensed and delensed spectra originate from the same region of sky. Fitting with a ΛCDM model and marginalizing over foregrounds, we find that the shift in cosmological parameters is consistent with zero. Our results show that gravitational lensing of the microwave background is internally consistent within the framework of the standard cosmological model.

We construct cosmic microwave background lensing mass maps using data from the 2014 and 2015 seasons of observations with the Atacama Cosmology Telescope (ACT). These maps cover 2100 square degrees of sky and overlap with a wide variety of optical surveys. The maps are signal dominated on large scales and have fidelity such that their correlation with the cosmic infrared background is clearly visible by eye. We also create lensing maps with thermal Sunyaev-Zel'dovich contamination removed using a novel cleaning procedure that only slightly degrades the lensing signal-to-noise ratio. The cross-spectrum between the cleaned lensing map and the BOSS CMASS galaxy sample is detected at 10σ significance, with an amplitude of A = 1.02 ± 0.10 relative to the Planck best-fitting Lambda cold dark matter cosmological model with fiducial linear galaxy bias. Our measurement lays the foundation for lensing cross-correlation science with current ACT data and beyond.

This paper presents a maximum-likelihood algorithm for combining sky maps with disparate sky coverage, angular resolution and spatially varying anisotropic noise into a single map of the sky. We use this to merge hundreds of individual maps covering the 2008–2018 ACT observing seasons, resulting in by far the deepest ACT maps released so far. We also combine the maps with the full Planck maps, resulting in maps that have the best features of both Planck and ACT: Planck’s nearly white noise on intermediate and large angular scales and ACT’s high-resolution and sensitivity on small angular scales. The maps cover over 18 000 square degrees, nearly half the full sky, at 100, 150 and 220 GHz. They reveal 4 000 optically-confirmed clusters through the Sunyaev Zel’dovich effect (SZ) and 18 500 point source candidates at > 5σ, the largest single collection of SZ clusters and millimeter wave sources to date. The multi-frequency maps provide millimeter images of nearby galaxies and individual Milky Way nebulae, and even clear detections of several nearby stars. Other anticipated uses of these maps include, for example, thermal SZ and kinematic SZ cluster stacking, CMB cluster lensing and galactic dust science. The method itself has negligible bias. However, due to the preliminary nature of some of the component data sets, we caution that these maps should not be used for precision cosmological analysis. The maps are part of ACT DR5, and will be made available on LAMBDA no later than three months after the journal publication of this article, along with an interactive sky atlas.

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.

We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg2 of the 2013–2016 survey, which covers >15000 deg2 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 ` = 4000. At large angular scales, foreground emission at 150 GHz is ∼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 ΛCDM for the ACT data alone with a prior on the optical depth of τ = 0.065 ± 0.015. ΛCDM is a good fit. The best-fit model has a reduced χ2 of 1.07 (PTE = 0.07) with H0 = 67.9 ± 1.5 km/s/Mpc. We show that the lensing BB signal is consistent with ΛCDM and limit the celestial EB polarization angle to ψP = −0.07◦ ±0.09◦. 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.

We use gravitational lensing of the cosmic microwave background (CMB) to measure the mass of the most distant blindly selected sample of galaxy clusters on which a lensing measurement has been performed to date. In CMB data from the the Atacama Cosmology Telescope and the Planck satellite, we detect the stacked lensing effect from 677 near-infrared-selected galaxy clusters from the Massive and Distant Clusters of WISE Survey (MaDCoWS), which have a mean redshift of zñ = 1.08. There are currently no representative optical weak lensing measurements of clusters that match the distance and average mass of this sample. We detect the lensing signal with a significance of 4.2s. We model the signal with a halo model framework to find the mean mass of the population from which these clusters are drawn. Assuming that the clusters follow Navarro–Frenk–White (NFW) density profiles, we infer a mean mass of M500cñ = (1.7 + 0.4) ´ 1014 M*. We consider systematic uncertainties from cluster redshift errors, centering errors, and the shape of the NFW profile. These are all smaller than 30% of our reported uncertainty. This work highlights the potential of CMB lensing to enable cosmological constraints from the abundance of distant clusters populating ever larger volumes of the observable universe, beyond the capabilities of optical weak lensing measurements.

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.

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 < ξ < 5. The confirmed sample has a median mass of M500c ~ 4.4 ´ 1014 M☉ h70 -1 and a median redshift of z = 0.49, and we have identified 44 strong gravitational lenses in the sample thus far. Radio data are used to characterize contamination to the SZ signal; the median contamination for confirmed clusters is predicted to be ∼1% of the SZ signal at the ξ > 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.

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 zmax = 1.38 ± 0.10. We expect this catalog to contain every galaxy cluster with M500c = 2.6 ×1014M⊙ h70-1 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 M500c = 2.7 ×1014M⊙ h70-1. 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.

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. Jointly fitting with BAO data, we find 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 and the sum of the neutrino masses to be 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.

We study the polarization properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg2 survey. We estimate the polarized power by stacking maps at known source positions, and correct for noise bias by subtracting the mean polarized power at random positions in the maps. We show that the method is unbiased using a set of simulated maps with similar noise properties to the real SPTpol maps. We find a flux-weighted mean-squared polarization fraction 〈p2〉= [8.9 ± 1.1] × 10−4 at 95 GHz and [6.9 ± 1.1] × 10−4 at 150 GHz for the full sample. This is consistent with the values obtained for a subsample of active galactic nuclei. For dusty sources, we find 95 per cent upper limits of 〈p2〉95 < 16.9 × 10−3 and 〈p2〉150 < 2.6 × 10−3. We find no evidence that the polarization fraction depends on the source flux or observing frequency. The 1σ upper limit on measured mean-squared polarization fraction at 150 GHz implies that extragalactic foregrounds will be subdominant to the CMB E and B mode polarization power spectra out to at least ℓ ≲ 5700 (ℓ ≲ 4700) and ℓ ≲ 5300 (ℓ ≲ 3600), respectively, at 95 (150) GHz.

We study the polarization properties of extragalactic sources at 95 and 150 GHz in the SPTpol 500 deg2 survey. We estimate the polarized power by stacking maps at known source positions, and correct for noise bias by subtracting the mean polarized power at random positions in the maps. We show that the method is unbiased using a set of simulated maps with similar noise properties to the real SPTpol maps. We find a flux-weighted mean-squared polarization fraction 〈p2〉= [8.9 ± 1.1] × 10−4 at 95 GHz and [6.9 ± 1.1] × 10−4 at 150 GHz for the full sample. This is consistent with the values obtained for a subsample of active galactic nuclei. For dusty sources, we find 95 per cent upper limits of 〈p2〉95 < 16.9 × 10−3 and 〈p2〉150 < 2.6 × 10−3. We find no evidence that the polarization fraction depends on the source flux or observing frequency. The 1σ upper limit on measured mean-squared polarization fraction at 150 GHz implies that extragalactic foregrounds will be subdominant to the CMB E and B mode polarization power spectra out to at least ℓ ≲ 5700 (ℓ ≲ 4700) and ℓ ≲ 5300 (ℓ ≲ 3600), respectively, at 95 (150) GHz.

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

We present a measurement of the cosmic microwave background lensing potential using 500 deg2 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L ≲ 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 < L < 2000 from sets of temperature-only (T), polarization-only (POL), and minimum-variance (MV) estimators. We measure the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit Λ cold dark matter model to the Planck 2015 TT + low P + lensing data set. For the minimum-variance estimator, we find =0.944 0.025 (Sys.) SRC=restricting to only polarization data, we find POL=0.906\pm 0.090 0.040. Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1σ) and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination.

The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of σ(r)=0.003. The large aperture telescope will map 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.

We use cosmic microwave background (CMB) temperature maps from the 500 deg 2 SPTpol survey to measure the stacked lensing convergence of galaxy clusters from the Dark Energy Survey (DES) Year-3 redMaPPer (RM) cluster catalog. The lensing signal is extracted through a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel'dovich (tSZ) effect. The modified estimator uses a tSZ-free map, constructed from the SPTpol 95 and 150 GHz data sets, to estimate the background CMB gradient. For lensing reconstruction, we employ two versions of the RM catalog: a flux-limited sample containing 4003 clusters and a volume-limited sample with 1741 clusters. We detect lensing at a significance of 8.7σ(6.7σ) with the flux (volume)-limited sample. By modeling the reconstructed convergence using the Navarro-Frenk-White profile, we find the average lensing masses to be M 200m = (1.62 -0.25+0.32 [stat] ± 0.04 [sys.]) and (1.28 -0.18+0.14 [stat] ± 0.03[sys.])× 10 14 M ⊙ for the volume- and flux-limited samples, respectively. The systematic error budget is much smaller than the statistical uncertainty and is dominated by the uncertainties in the RM cluster centroids. We use the volume-limited sample to calibrate the normalization of the mass-richness scaling relation, and find a result consistent with the galaxy weak-lensing measurements from DES.

We present measurements of the E-mode polarization angular auto-power spectrum (EE) and temperature-E-mode cross-power spectrum (TE) of the cosmic microwave background (CMB) using 150 GHz data from three seasons of SPTpol observations. We report the power spectra over the spherical harmonic multipole range 50 < ℓ ≤ 8000 and detect nine acoustic peaks in the EE spectrum with high signal-to-noise ratio. These measurements are the most sensitive to date of the EE and TE power spectra at ℓ > 1050 and ℓ > 1475, respectively. The observations cover 500 , a fivefold increase in area compared to previous SPTpol analyses, which increases our sensitivity to the photon diffusion damping tail of the CMB power spectra enabling tighter constraints on ΛCDM model extensions. After masking all sources with unpolarized flux mJy, we place a 95% confidence upper limit on residual polarized point-source power of at Dℓ = ℓ(ℓ+1)ℓℓ/2π < 0.107 μK2 at ℓ = 3000, suggesting that the EE damping tail dominates foregrounds to at least ℓ= 4050 with modest source masking. We find that the SPTpol data set is in mild tension with the ΛCDM model (2.1 δ), and different data splits prefer parameter values that differ at the ∼ 1 δ level. When fitting SPTpol data at ℓ < 1000, we find cosmological parameter constraints consistent with those for Planck temperature. Including SPTpol data at ℓ> 1000 results in a preference for a higher value of the expansion rate (H071.3 ± 2.1 Km s-1 Mpc-1) and a lower value for present-day density fluctuations (δ8 =0.77 ±0.02).

We present the temperature and polarization angular power spectra measured by the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg2 of sky on the celestial equator. We use these spectra, and the spectra measured with the MBAC camera on ACT from 2008-10, in combination with planck and wmap data to estimate cosmological parameters from the temperature, polarization, and temperature-polarization cross-correlations. We find the new ACTPol data to be consistent with the ΛCDM model. The ACTPol temperature-polarization cross-spectrum now provides stronger constraints on multiple parameters than the ACTPol temperature spectrum, including the baryon density, the acoustic peak angular scale, and the derived Hubble constant. The new ACTPol data provide information on damping tail parameters. The joint uncertainty on the number of neutrino species and the primordial helium fraction is reduced by 20% when adding ACTPol to Planck temperature data alone.

We report results from an analysis aimed at detecting the trispectrum of the kinematic Sunyaev-Zel'dovich (kSZ) effect by combining data from the South Pole Telescope (SPT) and Herschel-SPIRE experiments over a 100  deg^{2} field. The SPT observations combine data from the previous and current surveys, namely SPTpol and SPT-3G, to achieve depths of 4.5, 3, and 16  μK-arcmin in bands centered at 95, 150, and 220 GHz. For SPIRE, we include data from the 600 and 857 GHz bands. We reconstruct the velocity-induced large-scale correlation of the small-scale kSZ signal with a quadratic estimator that uses two cosmic microwave background (CMB) temperature maps, constructed by optimally combining data from all the frequency bands. We reject the null hypothesis of a zero trispectrum at 10.3σ level. However, the measured trispectrum contains contributions from both the kSZ and other undesired components, such as CMB lensing and astrophysical foregrounds, with kSZ being sub-dominant. We use the agora simulations to estimate the expected signal from CMB lensing and astrophysical foregrounds. After accounting for the contributions from CMB lensing and foreground signals, we do not detect an excess kSZ-only trispectrum and use this nondetection to set constraints on reionization. By applying a prior based on observations of the Gunn-Peterson trough, we obtain an upper limit on the duration of reionization of Δz&#95;{re,50}<4.5 (95% confidence level). We find these constraints are fairly robust to foregrounds assumptions. This trispectrum measurement is independent of, but consistent with, Planck's optical depth measurement. This result is the first constraint on the epoch of reionization using the non-Gaussian nature of the kSZ signal.

The Simons Observatory (SO) is a cosmic microwave background instrumentation suite in the Atacama Desert of Chile. More than 65,000 polarization-sensitive transition-edge sensor (TES) bolometers will be fielded in the frequency range spanning 27 to 280 GHz, with three separate dichroic designs. The mid-frequency 90/150 GHz and ultra-high-frequency 220/280 GHz detector arrays, fabricated at NIST, account for 39 of 49 total detector modules and implement the feedhorn-fed orthomode transducer-coupled TES bolometer architecture. A robust production-level fabrication framework for these detector arrays and the monolithic DC/RF routing wafers has been developed, which includes single device prototyping, process monitoring techniques, in-process metrology, and cryogenic measurements of critical film properties. Application of this framework has resulted in timely delivery of nearly 100 total superconducting focal plane components to SO with 88 % of detector wafers meeting nominal criteria for integration into a detector module: a channel yield > 95 % and T c in the targeted range., Competing Interests: Conflict of interestThe authors declare no conflict of interest., (© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2024.)

Purpose: The goal of this study is to determine if certain aspects of endophthalmitis prophylaxis strategies are superior to others., Design: This investigation is a systematic review and meta-analysis., Methods: All studies specifying a type of prophylaxis strategy and resulting rates of endophthalmitis were included. Time course, method of administration, and antibiotic regimen, and confounding factors were collected and included for meta-regression., Results: Time courses greater than 24 h did not significantly improve outcomes. Likewise, intraocular and/or intravenous antibiotic administration methods did not significantly outperform oral administration. No antibiotic regimens performed differently from vancomycin/ ≥ 3 rd generation cephalosporin except for ciprofloxacin monotherapy which yielded significantly worse outcomes., Conclusions: Future antibiotic strategies should strongly consider the risks of antibiotic treatment > 24 h and administration methods other than the oral antibiotic forms. In addition, providers should be wary of using ciprofloxacin monotherapy for endophthalmitis prophylaxis when treating open globe injuries., (© 2022. The Author(s).)

We describe the design and measurement of feedhorn-coupled, transition-edge sensor (TES) polarimeters with two passbands centered at 220 GHz and 280 GHz, intended for observations of the cosmic microwave background. Each pixel couples polarized light in two linear polarizations by use of a planar orthomode transducer and senses power via four TES bolometers, one for each band in each linear polarization. Previous designs of this detector architecture incorporated passbands from 27 to 220 GHz; we now demonstrate this technology at frequencies up to 315 GHz. Observational passbands are defined with an on-chip diplexer, and Fourier-transform-spectrometer measurements are in excellent agreement with simulations. We find coupling from feedhorn to TES bolometer using a cryogenic, temperature-controlled thermal source. We determine the optical efficiency of our device is η = 77% ± 6% (75% ± 5%) for 220 (280) GHz, relative to the designed passband shapes. Lastly, we compare two power-termination schemes commonly used in wide-bandwidth millimeter-wave polarimeters and find equal performance in terms of optical efficiency and passband shape.

We present a superconducting micro-resonator array fabrication method that is scalable and reconfigurable and has been optimized for high multiplexing factors. The method uses uniformly sized tiles patterned on stepper photolithography reticles as the building blocks of an array. We demonstrate this technique on a 101-element microwave kinetic inductance detector (MKID) array made from a titanium-nitride superconducting film. Characterization reveals 1.5% maximum fractional frequency spacing deviations caused primarily by material parameters that vary smoothly across the wafer. However, local deviations exhibit a Gaussian distribution in fractional frequency spacing with a standard deviation of 2.7 × 10 -3 . We exploit this finding to increase the yield of the BLAST-TNG 250 μm production wafer by placing resonators in the array close in both physical and frequency space. This array consists of 1836 polarization-sensitive MKIDs wired in three multiplexing groups. We present the array design and show that the achieved yield is consistent with our model of frequency collisions and is comparable to what has been achieved in other low temperature detector technologies.

Microwave Kinetic Inductance Detectors (MKIDs) provide a compelling path forward to the large-format polarimeter, imaging, and spectrometer arrays needed for next-generation experiments in millimeter-wave cosmology and astronomy. We describe the development of feedhorn-coupled MKID detectors for the TolTEC millimeter-wave imaging polarimeter being constructed for the 50-meter Large Millimeter Telescope (LMT). Observations with TolTEC are planned to begin in early 2019. TolTEC will comprise ∼7,000 polarization sensitive MKIDs and will represent the first MKID arrays fabricated and deployed on monolithic 150 mm diameter silicon wafers - a critical step towards future large-scale experiments with over 10 5 detectors. TolTEC will operate in observational bands at 1.1, 1.4, and 2.0 mm and will use dichroic filters to define a physically independent focal plane for each passband, thus allowing the polarimeters to use simple, direct-absorption inductive structures that are impedance matched to incident radiation. This work is part of a larger program at NIST-Boulder to develop MKID-based detector technologies for use over a wide range of photon energies spanning millimeter-waves to X-rays. We present the detailed pixel layout and describe the methods, tools, and flexible design parameters that allow this solution to be optimized for use anywhere in the millimeter and sub-millimeter bands. We also present measurements of prototype devices operating in the 1.1 mm band and compare the observed optical performance to that predicted from models and simulations.

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

Silicon nitride thin films play an important role in the realization of sensors, filters, and high-performance circuits. Estimates of the dielectric function in the far- and mid-IR regime are derived from the observed transmittance spectra for a commonly employed low-stress silicon nitride formulation. The experimental, modeling, and numerical methods used to extract the dielectric parameters with an accuracy of approximately 4% are presented.

Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gamma-ray microcalorimeters, based on transition-edge sensors (TESs), possible. At these collecting areas, gamma microcalorimeters can utilize their unprecedented energy resolution to perform spectroscopy in a number of applications that are limited by closely-spaced spectral peaks, for example, the nondestructive analysis of nuclear materials. We have built a 256 pixel spectrometer with an average full-width-at-half-maximum energy resolution of 53 eV at 97 keV, a useable dynamic range above 400 keV, and a collecting area of 5 cm(2). We have demonstrated multiplexed readout of the full 256 pixel array with 236 of the pixels (91%) giving spectroscopic data. This is the largest multiplexed array of TES microcalorimeters to date. This paper will review the spectrometer, highlighting the instrument design, detector fabrication, readout, operation of the instrument, and data processing. Further, we describe the characterization and performance of the newest 256 pixel array.