We describe the design of a new polarization sensitive receiver, spt-3g, for the 10-meter South Pole Telescope (spt). The spt-3g receiver will deliver a factor of ∼20 improvement in mapping speed over the current receiver, spt-pol. The sensitivity of the spt-3g receiver will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of the individual modes, i.e., maps. This will lead to precise (∼0.06 eV) constraints on the sum of neutrino masses with the potential to directly address the neutrino mass hierarchy. It will allow a separation of the lensing and inflationary B-mode power spectra, improving constraints on the amplitude and shape of the primordial signal, either through spt-3g data alone or in combination with bicep2/keck, which is observing the same area of sky. The measurement of small-scale temperature anisotropy will provide new constraints on the epoch of reionization. Additional science from the spt-3g survey will be significantly enhanced by the synergy with the ongoing optical Dark Energy Survey (des), including: a 1% constraint on the bias of optical tracers of large-scale structure, a measurement of the differential Doppler signal from pairs of galaxy clusters that will test General Relativity on ∼200 Mpc scales, and improved cosmological constraints from the abundance of clusters of galaxies.

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 ℓ 50 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 deg 2 , 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 50 > mJy, we place a 95% confidence upper limit on residual polarized point-source power of D ℓ ℓ C 1 2 0.107 K ℓ ℓ 2 p m = + < ( ) at ℓ 3000 = , suggesting that the EE damping

A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beamforming that characterized previous designs. The Pathfinder consists of two cylinders 37 m long by 20 m wide oriented northsouth for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ∼100 degrees by 1-2 degrees. Each CHIME Send correspondence to K.Bandura: E-mail: kevin.bandura@mcgill.ca arXiv:1406.2288v1 [astro-ph.IM] 9 Jun 2014Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ∼30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation.The lessons learned from its implementation will be used to inform and improve the final CHIME design.

We describe the observations and resultant galaxy cluster catalog from the 2770 deg 2 SPTpolExtended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete 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~´-M Mh 4.4 10 c 500 14 70 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 <4% of clusters have a predicted contamination >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 an overview of the design and status of the POLARBEAR-2 and the Simons Array experiments. POLARBEAR-2 is a Cosmic Microwave Background polarimetry experiment which aims to characterize the arc-minute angular scale B-mode signal from weak gravitational lensing and search for the degree angular scale B-mode signal from inflationary gravitational waves. The receiver has a 365 mm diameter focal plane cooled to 270 milli-Kelvin. The focal plane is filled with 7,588 dichroic lenslet-antenna coupled polarization sensitive Transition Edge Sensor (TES) bolometric pixels that are sensitive to 95 GHz and 150 GHz bands simultaneously. The TES bolometers are read-out by SQUIDs with 40 channel frequency domain multiplexing. Refractive optical elements are made with high purity alumina to achieve high optical throughput. The receiver is designed to achieve noise equivalent temperature of 5.8 µK CMB √ s in each frequency band. POLARBEAR-2 will deploy in 2016 in the Atacama desert in Chile. The Simons Array is a project to further increase sensitivity by deploying three POLARBEAR-2 type receivers. The Simons Array will cover 95 GHz, 150 GHz and 220 GHz frequency bands for foreground control. The Simons Array will be able to constrain tensor-to-scalar ratio and sum of neutrino masses to σ (r) = 6 × 10 −3 at r = 0.1 and ∑ m ν (σ = 1) to 40 meV.