Bulletin of the American Physical Society
APS April Meeting 2015
Volume 60, Number 4
Saturday–Tuesday, April 11–14, 2015; Baltimore, Maryland
Session X2: Cosmic Microwave Background |
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Sponsoring Units: DAP Chair: Raphael Flauger, Carnegie Mellon University Room: Holiday 1 |
Tuesday, April 14, 2015 10:45AM - 10:57AM |
X2.00001: Instrumentation Assembly, Characterization and Deployment of the Multichroic Detector Array for ACTPol Shuay-Pwu Ho The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive receiver for the 6 m Atacama Cosmology Telescope. ACTPol will make measurements of the small angular scale polarization anisotropies in the Cosmic Microwave Background (CMB). The deployment of the detector arrays for the receiver was fully completed in January, 2015. The entire focal plane is composed of three detector arrays, containing over 3000 transition edge sensors (TES) in total. The first two detector arrays, observing at 146 GHz were deployed in 2013 and 2014 respectively. The third and final array is designed to be multichroic, sensitive to both 90 GHz and 150 GHz, enabling increased sensitivity for observations of the CMB. In this talk I will focus on the laboratory assembly and characterization of the final detector array as well as its current status of deployment. [Preview Abstract] |
Tuesday, April 14, 2015 10:57AM - 11:09AM |
X2.00002: Measurement of CMB Polarization with the Atacama Cosmology Telescope Emily Grace The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization-sensitive receiver for the Atacama Cosmology Telescope designed to make sensitive, high-resolution measurements of the polarization anisotropies of the Cosmic Microwave Background (CMB) with the goal of investigating the properties of inflation, dark energy, dark matter, and neutrinos in the early Universe. The ACTPol receiver employs three kilo-pixel arrays of transition edge sensor (TES) bolometer detectors. The first and second of these arrays, which were deployed in 2013 and 2014, respectively, and observed at 146 GHz, are among the most sensitive millimeter-wave polarimeters currently fielded and demonstrate the significant polarization measurement capabilities of the ACTPol instrument. I will present an overview of the first two seasons of observations, discussing the optimization of the detector arrays, the on-sky instrument performance, the observation and data-reduction strategies, and the science results. [Preview Abstract] |
Tuesday, April 14, 2015 11:09AM - 11:21AM |
X2.00003: Atacama Cosmology Telescope: Polarization calibration analysis for CMB measurements with ACTPol and Advanced ACTPol Brian Koopman The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade for the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. Achieving first light in 2013, ACTPol is entering its third observation season. Advanced ACTPol is a next generation upgrade for ACTPol, with additional frequencies, polarization modulation, and new detector arrays, that will begin in 2016. I will first present an overview of the two projects and then focus on describing the methods used for polarization angle calibration of the ACTPol detectors. These methods utilize polarization ray tracing in the optical design software CODEV together with detector positions determined from planet observations and represent a critical input for mapping the polarization of the CMB. [Preview Abstract] |
Tuesday, April 14, 2015 11:21AM - 11:33AM |
X2.00004: SPTpol Results from the First 100 Square Degree Survey Abigail Crites SPTpol is a polarization-sensitive camera designed to measure the polarization of the cosmic microwave background (CMB) deployed on the 10 meter South Pole Telescope (SPT) in January 2012. I will present our recent results from the 100 square degree survey (the first year of data) focusing on the recently published high signal-to-noise measurement of the E-mode and temperature-E-mode correlation CMB power spectra. Additionally I will show B-mode power spectra, measurements of the gravitational lensing potential, and briefly report on the status of SPTpol results from the full 500 square degree survey. [Preview Abstract] |
Tuesday, April 14, 2015 11:33AM - 11:45AM |
X2.00005: Cosmological Constraints from Galaxy Clusters Identified in the 2500-square-degree SPT-SZ Survey Lindsey Bleem The South Pole Telescope (SPT) recently completed a three band mm-wavelength survey of $\sim$2500 deg$^2$ of the southern sky. One of the primary objectives of this survey was the creation of a mass-limited sample of galaxy clusters selected via the Sunyaev- Zel'dovich effect. In this talk I will present recent and upcoming cosmological results derived using a sample of 516 galaxy clusters identified in the SPT-SZ Survey. The abundance of such galaxy clusters is a powerful cosmological probe as it depends upon both the expansion history of the universe and the growth of density fluctuations. With projected improvements in mass calibration, the SPT cluster sample will constrain models of Dark Energy with a precision comparable to the best current constraints from geometric measurements of the universe, and, by measuring the effect of Dark Energy on the growth of structure, serve as an independent test of the standard dark energy paradigm. [Preview Abstract] |
Tuesday, April 14, 2015 11:45AM - 11:57AM |
X2.00006: A measurement of gravitational lensing of the Cosmic Microwave Background by galaxy clusters using data from the South Pole Telescope Eric Baxter Clusters of galaxies gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters using CMB data alone. We present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope's Sunyaev-Zel'dovich (SPT-SZ) survey. Several sources of potential systematic error are identified, but their combined effect on our measurement is found to be less than our statistical precision. We find that the cluster masses derived from our measurement of CMB lensing are consistent with those derived from the clusters' SZ signatures. [Preview Abstract] |
Tuesday, April 14, 2015 11:57AM - 12:09PM |
X2.00007: Richness-Mass relation and Optical-SZE Positional Offset Distribution for SPT Selected Clusters Alexandro Saro We cross-match clusters detected via their Sunyaev Zel'dovich effect in the 2500 deg$^2$ SPT-SZ survey carried out with the South Pole Telescope (SPT) with optically selected cluster catalogs extracted from the 250 deg$^2$ science verification data of the Dark Energy Survey: the RedMaPPer and the Voronoi Tessellation (VT) cluster catalogs.We use SPT derived masses and positions of these systems to characterize the RedMaPPer and VT cluster samples. We calibrate the RedMaPPer richness $\lambda$-mass relations for an SPT selected sample and show that it is characterized by low intrinsic scatter $\sim 18\%$, consistent with the $\lambda$-mass relation previously estimated by Rykoff et al.(2012), while the resulting VT richness $N_\textrm{vt}$-mass scaling relation is characterized by a larger intrinsic scatter $\sim 64\%$.We extend our matching algorithm to SPT selected cluster candidates with lower signal to noise ($4<\xi<4.5$) and show that increasing the matched sample by $\sim 44 \%$ with systems that have less well constrained SPT masses only marginally affects a low scatter mass proxy as $\lambda$.We study the offset distribution between the SPT-SZ centre and the optical centers and show that it contains both a dominant,centrally peaked population and a sub-dominant population. [Preview Abstract] |
Tuesday, April 14, 2015 12:09PM - 12:21PM |
X2.00008: Mapping matter jointly with CMB lensing and Large Scale Structure Kevin Huffenberger, Felipe Maldonado, Aditya Rotti In the near future, Stage III and Stage IV Cosmic Microwave Background experiments will measure to high precision the lensing distortions that trace matter fluctuations in the universe. On a similar timescale, WFIRST, EUCLID, DESI, LSST, and other surveys will provide galaxy redshift information, imaging, and cosmic shear data over large regions of the sky. Taking a holistic, Bayesian approach to combine datasets, we seek to understand keenly the statistical properties of joint estimates of the matter distribution and its correlations, including their non-Gaussian likelihoods. [Preview Abstract] |
Tuesday, April 14, 2015 12:21PM - 12:33PM |
X2.00009: Disproof of Big Bang's Foundational Expansion Redshift Assumption Overthrows the Big Bang and Its No-Center Universe and Is Replaced by a Spherically Symmetric Model with Nearby Center with the 2.73K CMR Explained by Vacuum Gravity and Doppler Effects Robert Gentry Big bang theory holds its central expansion redshift assumption quickly reduced the theorized radiation flash to $\sim$10$^{10}$ K, and then over 13.8 billion years reduced it further to the present 2.73K CMR. Weinberg claims this 2.73K value agrees with big bang theory so well that ``...we can be sure that this radiation was indeed left over from a time about a million years after the `big bang.' '' (TF3M, p180, 1993 ed.) Actually his conclusion is all based on big bang's in-flight wavelength expansion being a valid physical process. In fact all his surmising is nothing but science fiction because our disproof of GR-induced in-flight wavelength expansion [1] definitely proves the 2.73K CMR could never have been the wavelength-expanded relic of any radiation, much less the presumed big bang's. This disproof of big bang's premier prediction is a death blow to the big bang as it is also to the idea that the redshifts in Hubble's redshift relation are expansion shifts; this negates Friedmann's everywhere-the-same, no-center universe concept and proves it does have a nearby Center, a place which can be identified in Psalm 103:19 and in Revelation 20:11 as the location of God's eternal throne. Widely published (Science, Nature, ARNS) evidence of Earth's fiat creation will also be presented. [Preview Abstract] |
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