[en] Here, we present the results of an X-ray spectral analysis of 153 galaxy clusters observed with the Chandra, XMM-Newton, and Suzaku space telescopes. These clusters, which span 0 < z < 1.5, were drawn from a larger, mass-selected sample of galaxy clusters discovered in the 2500 square degree South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. With a total combined exposure time of 9.1 Ms, these data yield the strongest constraints to date on the evolution of the metal content of the intracluster medium (ICM). We find no evidence for strong evolution in the global (r < R _5_0_0) ICM metallicity (dZ/dz = –0.06 ± 0.04 Z ⊙), with a mean value at z = 0.6 of 〈Z〉=0.23±0.01 Z ⊙ and a scatter of σ Z = 0.08 ± 0.01 Z ⊙. These results imply that the emission-weighted metallicity has not changed by more than 40% since z = 1 (at 95% confidence), consistent with the picture of an early (z > 1) enrichment. We find, in agreement with previous works, a significantly higher mean value for the metallicity in the centers of cool core clusters versus non-cool core clusters. We find weak evidence for evolution in the central metallicity of cool core clusters (dZ/dz = –0.21 ± 0.11 Z ⊙), which is sufficient to account for this enhanced central metallicity over the past ~10 Gyr. We find no evidence for metallicity evolution outside of the core (dZ/dz = –0.03 ± 0.06 Z ⊙), and no significant difference in the core-excised metallicity between cool core and non-cool core clusters. This suggests that strong radio-mode active galactic nucleus feedback does not significantly alter the distribution of metals at r>0.15R_5_0_0. Given the limitations of current-generation X-ray telescopes in constraining the ICM metallicity at z > 1, significant improvements on this work will likely require next-generation X-ray missions

[en] We present maps of the Large and Small Magellanic Clouds from combined South Pole Telescope (SPT) and Planck data. The Planck satellite observes in nine bands, while the SPT data used in this work were taken with the three-band SPT-SZ camera, The SPT-SZ bands correspond closely to three of the nine Planck bands, namely those centered at 1.4, 2.1, and 3.0 mm. The angular resolution of the Planck data ranges from 5 to 10 arcmin, while the SPT resolution ranges from 1.0 to 1.7 arcmin. The combined maps take advantage of the high resolution of the SPT data and the long-timescale stability of the space-based Planck observations to deliver robust brightness measurements on scales from the size of the maps down to ∼1 arcmin. In each band, we first calibrate and color-correct the SPT data to match the Planck data, then we use noise estimates from each instrument and knowledge of each instrument’s beam to make the inverse-variance-weighted combination of the two instruments’ data as a function of angular scale. We create maps assuming a range of underlying emission spectra and at a range of final resolutions. We perform several consistency tests on the combined maps and estimate the expected noise in measurements of features in them. We compare maps from this work to those from the Herschel HERITAGE survey, finding general consistency between the data sets. All data products described in this paper are available for download from the NASA Legacy Archive for Microwave Background Data Analysis server.

[en] We present a measurement of the cosmic microwave background (CMB) gravitational lensing potential using data from the first two seasons of observations with SPTpol, the polarization-sensitive receiver currently installed on the South Pole Telescope. The observations used in this work cover 100 deg² of sky with arcminute resolution at 150 GHz. Using a quadratic estimator, we make maps of the CMB lensing potential from combinations of CMB temperature and polarization maps. We combine these lensing potential maps to form a minimum-variance (MV) map. The lensing potential is measured with a signal-to-noise ratio of greater than one for angular multipoles between $100<<!--\; <\; -->L<<!--\; <\; -->250$. This is the highest signal-to-noise mass map made from the CMB to date and will be powerful in cross-correlation with other tracers of large-scale structure. We calculate the power spectrum of the lensing potential for each estimator, and we report the value of the MV power spectrum between $100<<!--\; <\; -->L<<!--\; <\; -->2000$ as our primary result. We constrain the ratio of the spectrum to a fiducial ΛCDM model to be A_MV = 0.92 ± 0.14 (Stat.) ± 0.08 (Sys.). Restricting ourselves to polarized data only, we find A_POL = 0.92 ± 0.24 (Stat.) ± 0.11 (Sys.). This measurement rejects the hypothesis of no lensing at $5.9\mathrm{\sigma <!--\; ??\; -->}$ using polarization data alone, and at $14\mathrm{\sigma <!--\; ??\; -->}$ using both temperature and polarization data.

[en] The Simons Array (SA) is a cosmic microwave background (CMB) polarization experiment comprised of three telescopes that will observe the CMB at 90, 150, 220, and 270 GHz with more than 22,000 Transition Edge Sensor (TES) bolometers. The cryogenic receivers inside each telescope are named POLARBEAR-2a, POLARBEAR-2b, and POLARBEAR-2c (PB-2a, PB-2b, and PB-2c, respectively). To allow for the large number of detectors, SA uses frequency-division multiplexing with multiplexing factor of 40. We describe the process developed to assemble the readout circuit repeatably for SA. After assembly, we characterize the readout circuit and TESs at cryogenic temperatures in a condition of negligible incident optical power. Impedances in the readout circuit bias our estimates of TES parameters, and we describe a method to account for this.

[en] We present measurements of E-mode polarization and temperature-E-mode correlation in the cosmic microwave background using data from the first season of observations with SPTpol, the polarization-sensitive receiver currently installed on the South Pole Telescope (SPT). The observations used in this work cover 100 ${\mathrm{d}\mathrm{e}\mathrm{g}}^2$ of sky with arcminute resolution at 150 GHz. We report the E-mode angular auto-power spectrum (EE) and the temperature-E-mode angular cross-power spectrum (TE) over the multipole range 500 < ℓ ≤ 5000. These power spectra improve on previous measurements in the high-ℓ (small-scale) regime. We fit the combination of the SPTpol power spectra, data from Planck, and previous SPT measurements with a six-parameter ΛCDM cosmological model. We find that the best-fit parameters are consistent with previous results. The improvement in high-ℓ sensitivity over previous measurements leads to a significant improvement in the limit on polarized point-source power: after masking sources brighter than 50 mJy in unpolarized flux at 150 GHz, we find a 95% confidence upper limit on unclustered point-source power in the EE spectrum of $D_{\mathrm{\ell <!--\; ???\; -->}}=\mathrm{\ell <!--\; ???\; -->}(\mathrm{\ell <!--\; ???\; -->}+1)C_{\mathrm{\ell <!--\; ???\; -->}}/2\mathrm{\pi <!--\; ??\; -->}<<!--\; <\; -->0.40\mathrm{\mu <!--\; ??\; -->}{\mathrm{K}}^2$ at $\mathrm{\ell <!--\; ???\; -->}=3000$, indicating that future EE measurements will not be limited by power from unclustered point sources in the multipole range $\mathrm{\ell <!--\; ???\; -->}<<!--\; <\; -->3600$, and possibly much higher in $\mathrm{\ell <!--\; ???\; -->}.$

[en] The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg² patch of sky centered at R.A. 23^h30^m and decl. −55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. One candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low ( p = 0.01) to confirm detection.

[en] In this work, we have measured the properties of membrane-suspended bolometer thermal links and microstrip transmission lines in the transition-edge sensor arrays for the third-generation camera for South Pole Telescope (SPT-3G). A promising technique for controlling the end point of the release etch that defines the thermal link has been developed. We have also evaluated the microstrip loss in our detectors by measuring the optical efficiency of detectors with different lengths of microstrip line. The loss tangent is sufficiently low for the use in multi-chronic pixels for cosmic microwave background instruments like SPT-3G.

[en] We present cosmological parameter constraints obtained from galaxy clusters identified by their Sunyaev–Zel’dovich effect signature in the 2500 square-degree South Pole Telescope Sunyaev Zel’dovich (SPT-SZ) survey. We consider the 377 cluster candidates identified at $z><!--\; >\; -->0.25$ with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming a spatially flat ΛCDM cosmology, we combine the cluster data with a prior on H ₀ and find ${\mathrm{\sigma <!--\; ??\; -->}}_8=0.784\pm <!--\; ??\; -->0.039$ and ${\mathrm{\Omega <!--\; ??\; -->}}_m=0.289\pm <!--\; ??\; -->0.042$, with the parameter combination ${\mathrm{\sigma <!--\; ??\; -->}}_8{({\mathrm{\Omega <!--\; ??\; -->}}_m/0.27)}^{0.3}=0.797\pm <!--\; ??\; -->0.031$. These results are in good agreement with constraints from the cosmic microwave background (CMB) from SPT, WMAP, and Planck, as well as with constraints from other cluster data sets. We also consider several extensions to ΛCDM, including models in which the equation of state of dark energy w, the species-summed neutrino mass, and/or the effective number of relativistic species ($N_{\mathrm{e}\mathrm{f}\mathrm{f}}$) are free parameters. When combined with constraints from the Planck CMB, H ₀, baryon acoustic oscillation, and SNe, adding the SPT cluster data improves the w constraint by 14%, to $w=-<!--\; ???\; -->1.023\pm <!--\; ??\; -->0.042$.

[en] The South Pole Telescope third-generation (SPT-3G) receiver was installed during the austral summer of 2016–2017. It is designed to measure the cosmic microwave background across three frequency bands centered at 95, 150, and 220 GHz. The SPT-3G receiver has ten focal plane modules, each with 269 pixels. Each pixel features a broadband sinuous antenna coupled to a niobium microstrip transmission line. In-line filters define the desired band-passes before the signal is coupled to six bolometers with Ti/Au/Ti/Au transition edge sensors (three bands $\times <!--\; ??\; -->$ two polarizations). In total, the SPT-3G receiver is composed of 16,000 detectors, which are read out using a 68$\times <!--\; ??\; -->$ frequency-domain multiplexing scheme. In this paper, we present the process employed in fabricating the detector arrays.

[en] LiteBIRD is a candidate satellite for a strategic large mission of JAXA. With its expected launch in the middle of the 2020s with a H3 rocket, LiteBIRD plans to map the polarization of the cosmic microwave background radiation over the full sky with unprecedented precision. The full success of LiteBIRD is to achieve $\mathrm{\delta <!--\; ??\; -->}r<0.001$, where $\mathrm{\delta <!--\; ??\; -->}r$ is the total error on the tensor-to-scalar ratio r. The required angular coverage corresponds to $2\le <!--\; ???\; -->\mathrm{\ell <!--\; ???\; -->}\le <!--\; ???\; -->200$, where $\mathrm{\ell <!--\; ???\; -->}$ is the multipole moment. This allows us to test well-motivated cosmic inflation models. Full-sky surveys for 3 years at a Lagrangian point L2 will be carried out for 15 frequency bands between 34 and 448 GHz with two telescopes to achieve the total sensitivity of 2.5 μK arcmin with a typical angular resolution of 0.5${}^{\circ <!--\; ???\; -->}$ at 150 GHz. Each telescope is equipped with a half-wave plate system for polarization signal modulation and a focal plane filled with polarization-sensitive TES bolometers. A cryogenic system provides a 100 mK base temperature for the focal planes and 2 K and 5 K stages for optical components.