DOCSLIB.ORG

UC Berkeley UC Berkeley Electronic Theses and Dissertations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
UC Berkeley UC Berkeley Electronic Theses and Dissertations UC Berkeley UC Berkeley Electronic Theses and Dissertations Title The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales Permalink https://escholarship.org/uc/item/2z74c4rc Author Shirokoff, Erik D. Publication Date 2011 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales by Erik D. Shirokoff A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor William Holzapfel, Chair Professor Bernard Sadoulet Professor Chung-Pei Ma Fall 2011 The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales Copyright 2011 by Erik D. Shirokoff 1 Abstract The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales by Erik D. Shirokoff Doctor of Philosophy in Physics University of California, Berkeley Professor William Holzapfel, Chair The South Pole Telescope (SPT) is a dedicated 10-meter diameter telescope optimized for mm-wavelength surveys of the Cosmic Microwave Background (CMB) with arcminute reso- lution. The first instrument deployed at SPT features a 960 element array of horn-coupled bolometers. These devices consist of fully lithographed spider-web absorbers and aluminum- titanium bilayer transition edge sensors fabricated on adhesive-bonded silicon wafers with embedded metal backplanes. The focal plane is cooled using a closed cycle pulse-tube re- frigerator, and read-out using Frequency Domain Multiplexed Superconducting Quantum Interference Devices (SQUIDs.) Design features were chosen to optimize sensitivy in the atmospheric observing bands available from the ground, and for stability with the frequency domain multiplexed readout system employed at SPT, and performance was verified with a combination of laboratory tests and field observations. In 2008 the SPT surveyed 200 square-degrees at 150 and 220 GHz. These data have been analyzed using a cross-spectrum analysis and multi-band Markov Chain Monte Carlo parameter fitting using a model that includes lensed primary CMB anisotropy, secondary thermal (tSZ) and kinetic (kSZ) Sunyaev-Zel'dovich anisotropies, unclustered synchrotron point sources, and clustered dusty point sources. In addition to measuring the power spectrum of dusty galaxies at high signal-to-noise, the data primarily constrain a linear combination of the kSZ and tSZ anisotropy contributions (at 150 GHz and ` = 3000): tSZ kSZ 2 D3000 + 0:5 D3000 = 4:5 ± 1:0 µK , and place the lowest limits yet measured on secondary anisotropy power. i To Dennis who taught me how to solder and introduced me to the world of ideas. ii Contents List of Figures vi List of Tables viii I Introduction and scientific motivation 1 1 Concordance cosmology & large scale structure 2 1.1 Introduction . .2 1.2 Concordance cosmology . .3 1.2.1 The ΛCDM world model . .3 1.2.2 Cosmological parameters . .6 1.3 The Cosmic Microwave Background . .7 1.4 Large scale structure . 10 1.4.1 Growth of perturbations . 10 1.4.2 Normalization and σ8 ........................... 13 1.4.3 The mass function . 14 1.4.4 Baryons and large scale structure . 16 1.4.5 The Halo Model . 17 1.4.6 Galaxy cluster halo profiles . 18 1.4.7 Other observables . 20 1.5 The SZ effects . 22 1.6 SZ contributions to the CMB power spectrum . 24 1.6.1 Early SZ results . 24 1.6.2 Recent SZ results . 27 iii 2 The South Pole Telescope 33 2.1 The Telescope . 33 2.2 The Receiver . 35 2.2.1 Optical and Mechanical Design . 35 2.2.2 Frequency Domain Multiplexing . 37 2.2.3 Focal plane modifications . 37 II The South Pole Telescope SZ Camera Detectors 39 3 Transition Edge Sensor bolometers 40 3.1 Introduction . 40 3.2 TES bolometer review . 43 3.2.1 A simple TES model . 43 3.2.2 TES Equations of motion . 44 3.2.3 TES responsivity . 48 3.2.4 TES stability . 50 3.3 TES with BLING . 52 3.4 A TES model with three thermal masses . 55 3.5 TES Sensitivity . 58 3.5.1 Noise Equivalent Power . 58 3.5.2 Photon noise . 59 3.5.3 Thermal carrier noise . 60 3.5.4 Bolometer Johnson Noise . 61 3.5.5 Readout noise . 62 3.5.6 Low frequency noise . 63 3.5.7 Excess noise . 64 3.6 Optimizing thermal properties of real devices . 65 3.6.1 Multi-component thermal links . 65 3.6.2 Tc Optimization . 67 3.7 A summary of TES results . 68 4 Device design and fabrication 72 4.1 Introduction . 72 4.2 The design of SPT devices . 72 4.2.1 Design overview . 72 4.2.2 Reflective back-plane position and wafer bonding . 76 4.3 Fabrication . 77 4.3.1 Low Stress Nitride deposition . 77 4.3.2 Back-plane deposition and wafer bonding . 79 4.3.3 Alternate bonding techniques . 80 iv 4.3.4 TES bilayer . 82 4.3.5 TES and lead fabrication . 85 4.3.6 Gold deposition . 87 4.3.7 LSN Spiderweb . 88 4.3.8 Release of suspended structures . 89 4.3.9 Final photoresist ash and inspection . 91 4.4 Mechanical housing and readout electronics . 92 5 Detector Performance 93 5.1 Introduction . 93 5.2 Device parameters . 93 5.3 Electrothermal response . 96 5.4 Optical Response . 98 5.5 Yield . 101 5.6 Sensitivity and Noise Equivalent Power . 102 5.7 Discussion . 105 III Secondary CMB anisotropies measured with SPT 107 6 CMB Secondary anisotropies 108 6.1 Introduction . 108 6.2 Instrument and Observations . 109 6.2.1 Beam Functions . 110 6.2.2 Calibration . 111 6.3 Analysis . 112 6.3.1 TODs to Maps . 112 6.3.2 Maps to Bandpowers . 113 6.4 Jackknife tests . 116 6.5 Power spectra . 118 6.6 Cosmological model . 118 6.6.1 Primary CMB Anisotropy . 122 6.6.2 Secondary CMB Anisotropy . 122 6.6.3 Foregrounds . 125 6.6.4 Effective frequencies of the SPT bands . 129 6.7 Parameter results . 130 6.7.1 Baseline model results . 130 6.7.2 kSZ variants . 133 6.7.3 Clustered DSFG extensions to the baseline model . 134 6.7.4 tSZ-DSFG correlation . 138 6.7.5 Comparing differenced spectra results to multi-frequency fits . 140 v 6.8 Consequences of the measured tSZ Signal . 144 6.8.1 Thermal SZ amplitude . 144 6.8.2 σ8 Constraints . 148 6.9 Discussion . 151 7 Conclusion 154 vi List of Figures 1.1 CMB primary spectrum . .8 1.2 HOD fits to SDSS data . 18 1.3 SZ map and profile for a massive cluster, A 2744. 24 1.4 Previous measurements of the high-` power spectrum at 30 GHz ....... 26 1.5 tSZ power contribution vs. redshift and mass . 28 1.6 Analytic model for the tSZ power spectrum from Shaw et al. (2010) compared to simulations. 31 2.1 SPT Optical design . 34 2.2 SPT secondary cryostat . ..
Load more

Recommended publications
  • Measurement of the Cosmic Microwave Background Polarization with the BICEP Telescope at the South Pole
    UC Berkeley UC Berkeley Electronic Theses and Dissertations Title Measurement of the Cosmic Microwave Background Polarization with the BICEP Telescope at the South Pole Permalink https://escholarship.org/uc/item/6b98h32b Author Takahashi, Yuki David Publication Date 2010 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California Measurement of the Cosmic Microwave Background Polarization with the Bicep Telescope at the South Pole by Yuki David Takahashi A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor William L. Holzapfel, Chair Professor Adrian T. Lee Professor Chung-Pei Ma Fall 2010 Measurement of the Cosmic Microwave Background Polarization with the Bicep Telescope at the South Pole Copyright 2010 by Yuki David Takahashi 1 Abstract Measurement of the Cosmic Microwave Background Polarization with the Bicep Telescope at the South Pole by Yuki David Takahashi Doctor of Philosophy in Physics University of California, Berkeley Professor William L. Holzapfel, Chair The question of how exactly the universe began is the motivation for this work. Based on the discoveries of the cosmic expansion and of the cosmic microwave background (CMB) ra- diation, humans have learned of the Big Bang origin of the universe. However, what exactly happened in the first moments of the Big Bang? A scenario of initial exponential expansion called “inflation” was proposed in the 1980s, explaining several important mysteries about the universe. Inflation would have generated gravitational waves that would have left a unique imprint in the polarization of the CMB.
    [Show full text]
  • Integrated Sachs Wolfe Effect and Rees Sciama Effect
    Prog. Theor. Exp. Phys. 2012, 00000 (24 pages) DOI: 10.1093/ptep/0000000000 Integrated Sachs Wolfe Effect and Rees Sciama Effect Atsushi J. Nishizawa1 1 Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), The University of Tokyo, Chiba 277-8582, Japan ∗E-mail: [email protected] ............................................................................... It has been around fifty years since R. K. Sachs and A. M. Wolfe predicted the existence of anisotropy in the Cosmic Microwave Background (CMB) and ten years since the integrated Sachs Wolfe effect (ISW) was first detected observationally. The ISW effect provides us with a unique probe of the accelerating expansion of the Universe. The cross-correlation between the large-scale structure and CMB has been the most promising way to extract the ISW effect from the data. In this article, we review the physics of the ISW effect and summarize recent observational results and interpretations. ................................................................................................. Subject Index Cosmological perturbation theory, Cosmic background radiations, Dark energy and dark matter 1. Overview After the discovery of the isotropic radiation of the Cosmic Microwave Background (CMB) of the Universe by A. A. Penzias and R. W. Wilson in 1965 [100], R. K. Sachs and A. M Wolfe predict the existence of anisotropy in the CMB associated with the gravitational redshift in 1967 [116]. They fully integrate the geodesic equation in a perturbed Friedman-Robertson-Walker (FRW) metric in the fully general relativistic framework. The Sachs-Wolfe (SW) is the first paper that predicts the presence of the anisotropy in the CMB which now plays an important role for constraining cosmo- logical models, the nature of dark energy, modified gravity, and non-Gaussianity of the primordial fluctuation.
    [Show full text]
  • CMB Telescopes and Optical Systems to Appear In: Planets, Stars and Stellar Systems (PSSS) Volume 1: Telescopes and Instrumentation
    CMB Telescopes and Optical Systems To appear in: Planets, Stars and Stellar Systems (PSSS) Volume 1: Telescopes and Instrumentation Shaul Hanany ([email protected]) University of Minnesota, School of Physics and Astronomy, Minneapolis, MN, USA, Michael Niemack ([email protected]) National Institute of Standards and Technology and University of Colorado, Boulder, CO, USA, and Lyman Page ([email protected]) Princeton University, Department of Physics, Princeton NJ, USA. March 26, 2012 Abstract The cosmic microwave background radiation (CMB) is now firmly established as a funda- mental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB ob- servations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by arXiv:1206.2402v1 [astro-ph.IM] 11 Jun 2012 the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We con- clude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.
    [Show full text]
  • The Design of the Ali CMB Polarization Telescope Receiver
    The design of the Ali CMB Polarization Telescope receiver M. Salatinoa,b, J.E. Austermannc, K.L. Thompsona,b, P.A.R. Aded, X. Baia,b, J.A. Beallc, D.T. Beckerc, Y. Caie, Z. Changf, D. Cheng, P. Chenh, J. Connorsc,i, J. Delabrouillej,k,e, B. Doberc, S.M. Duffc, G. Gaof, S. Ghoshe, R.C. Givhana,b, G.C. Hiltonc, B. Hul, J. Hubmayrc, E.D. Karpela,b, C.-L. Kuoa,b, H. Lif, M. Lie, S.-Y. Lif, X. Lif, Y. Lif, M. Linkc, H. Liuf,m, L. Liug, Y. Liuf, F. Luf, X. Luf, T. Lukasc, J.A.B. Matesc, J. Mathewsonn, P. Mauskopfn, J. Meinken, J.A. Montana-Lopeza,b, J. Mooren, J. Shif, A.K. Sinclairn, R. Stephensonn, W. Sunh, Y.-H. Tsengh, C. Tuckerd, J.N. Ullomc, L.R. Valec, J. van Lanenc, M.R. Vissersc, S. Walkerc,i, B. Wange, G. Wangf, J. Wango, E. Weeksn, D. Wuf, Y.-H. Wua,b, J. Xial, H. Xuf, J. Yaoo, Y. Yaog, K.W. Yoona,b, B. Yueg, H. Zhaif, A. Zhangf, Laiyu Zhangf, Le Zhango,p, P. Zhango, T. Zhangf, Xinmin Zhangf, Yifei Zhangf, Yongjie Zhangf, G.-B. Zhaog, and W. Zhaoe aStanford University, Stanford, CA 94305, USA bKavli Institute for Particle Astrophysics and Cosmology, Stanford, CA 94305, USA cNational Institute of Standards and Technology, Boulder, CO 80305, USA dCardiff University, Cardiff CF24 3AA, United Kingdom eUniversity of Science and Technology of China, Hefei 230026 fInstitute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 gNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 hNational Taiwan University, Taipei 10617 iUniversity of Colorado Boulder, Boulder, CO 80309, USA jIN2P3, CNRS, Laboratoire APC, Universit´ede Paris, 75013 Paris, France kIRFU, CEA, Universit´eParis-Saclay, 91191 Gif-sur-Yvette, France lBeijing Normal University, Beijing 100875 mAnhui University, Hefei 230039 nArizona State University, Tempe, AZ 85004, USA oShanghai Jiao Tong University, Shanghai 200240 pSun Yat-Sen University, Zhuhai 519082 ABSTRACT Ali CMB Polarization Telescope (AliCPT-1) is the first CMB degree-scale polarimeter to be deployed on the Tibetan plateau at 5,250 m above sea level.
    [Show full text]
  • Cosmic Microwave Background
    1 29. Cosmic Microwave Background 29. Cosmic Microwave Background Revised August 2019 by D. Scott (U. of British Columbia) and G.F. Smoot (HKUST; Paris U.; UC Berkeley; LBNL). 29.1 Introduction The energy content in electromagnetic radiation from beyond our Galaxy is dominated by the cosmic microwave background (CMB), discovered in 1965 [1]. The spectrum of the CMB is well described by a blackbody function with T = 2.7255 K. This spectral form is a main supporting pillar of the hot Big Bang model for the Universe. The lack of any observed deviations from a 7 blackbody spectrum constrains physical processes over cosmic history at redshifts z ∼< 10 (see earlier versions of this review). Currently the key CMB observable is the angular variation in temperature (or intensity) corre- lations, and to a growing extent polarization [2–4]. Since the first detection of these anisotropies by the Cosmic Background Explorer (COBE) satellite [5], there has been intense activity to map the sky at increasing levels of sensitivity and angular resolution by ground-based and balloon-borne measurements. These were joined in 2003 by the first results from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP)[6], which were improved upon by analyses of data added every 2 years, culminating in the 9-year results [7]. In 2013 we had the first results [8] from the third generation CMB satellite, ESA’s Planck mission [9,10], which were enhanced by results from the 2015 Planck data release [11, 12], and then the final 2018 Planck data release [13, 14]. Additionally, CMB an- isotropies have been extended to smaller angular scales by ground-based experiments, particularly the Atacama Cosmology Telescope (ACT) [15] and the South Pole Telescope (SPT) [16].
    [Show full text]
  • Physics of the Cosmic Microwave Background Anisotropy∗
    Physics of the cosmic microwave background anisotropy∗ Martin Bucher Laboratoire APC, Universit´eParis 7/CNRS B^atiment Condorcet, Case 7020 75205 Paris Cedex 13, France [email protected] and Astrophysics and Cosmology Research Unit School of Mathematics, Statistics and Computer Science University of KwaZulu-Natal Durban 4041, South Africa January 20, 2015 Abstract Observations of the cosmic microwave background (CMB), especially of its frequency spectrum and its anisotropies, both in temperature and in polarization, have played a key role in the development of modern cosmology and our understanding of the very early universe. We review the underlying physics of the CMB and how the primordial temperature and polarization anisotropies were imprinted. Possibilities for distinguish- ing competing cosmological models are emphasized. The current status of CMB ex- periments and experimental techniques with an emphasis toward future observations, particularly in polarization, is reviewed. The physics of foreground emissions, especially of polarized dust, is discussed in detail, since this area is likely to become crucial for measurements of the B modes of the CMB polarization at ever greater sensitivity. arXiv:1501.04288v1 [astro-ph.CO] 18 Jan 2015 1This article is to be published also in the book \One Hundred Years of General Relativity: From Genesis and Empirical Foundations to Gravitational Waves, Cosmology and Quantum Gravity," edited by Wei-Tou Ni (World Scientific, Singapore, 2015) as well as in Int. J. Mod. Phys. D (in press).
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE Ming-Tang Chen, Ph.D., Physics Research Fellow Deputy Director of ASIAA Hawaii Operations Academia Sinica, Institute of Astronomy and Astrophysics (Taiwan) PO Box 23-141, Taipei, Taiwan, ROC (USA) 645 N. A’ohoku Place, Hilo, HI 96720, USA Telephone (TW): +886-2-2366-5348 Telephone (US): +1-808-938-4708 Email: [email protected] CURRICULUM VITAE ................................................................................................... 1 Brief Biography: .............................................................................................................. 2 Person Data: ..................................................................................................................... 2 Education: ........................................................................................................................ 2 Knowledge & Skills: ....................................................................................................... 2 Professional TitleS: .......................................................................................................... 2 Committee Service: ......................................................................................................... 3 Grant Executed: ............................................................................................................... 4 International Invited Talks: ............................................................................................. 5 Current and Past Research Topics: .................................................................................
    [Show full text]
  • The Big Bang, the South Pole, and Everything
    The Big Bang, the South Pole, and Everything Spectrum's Glenn Zorpette reports from Antarctica This is part of the series: Antarctica: Life on the Ice Transcript: The Big Bang, the South Pole, and Everything Glenn Zorpette: The South Pole is a great place to study origins of the universe. Here’s why. One of the main things that cosmologists do is analyze the microwave radiation that permeates the universe. That radiation is called the cosmic microwave background, and you can think of it as an echo of the big bang that launched the universe into the glorious spectacle that we see today. With its dry, stable atmosphere, the South Pole offers outstanding viewing conditions for two microwave telescopes that could unravel the deepest mysteries of the universe. [clanking/talking sounds] Glenn Zorpette: Physicist John Carlstrom of the University of Chicago leads the way up to the roof of the South Pole Telescope. It towers five stories above the powdery white snow. [clanking sound up for 1 to 2 seconds then fade] John Carlstrom: This is a 10-meter diameter—it’s actually a little larger, but 10 meters as it’s projected toward the sky—telescope for looking at radiation from the big bang, what we call the cosmic microwave background radiation. Glenn Zorpette: Carlstrom is the mastermind behind this [US] $19 million telescope. He explains that the cosmic microwave background radiation is like an echo reaching us from 13.7 billion years ago. John Carlstrom: And it allows us to take a snapshot, see what the universe was like.
    [Show full text]
  • The Atacama Cosmology Telescope: Likelihood for Small-Scale CMB Data
    Home Search Collections Journals About Contact us My IOPscience The Atacama Cosmology Telescope: likelihood for small-scale CMB data This content has been downloaded from IOPscience. Please scroll down to see the full text. JCAP07(2013)025 (http://iopscience.iop.org/1475-7516/2013/07/025) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 146.155.214.33 This content was downloaded on 11/01/2017 at 16:28 Please note that terms and conditions apply. You may also be interested in: The Atacama Cosmology Telescope: cosmological parameters from three seasons of data Jonathan L. Sievers, Renée A. Hlozek, Michael R. Nolta et al. THE ATACAMA COSMOLOGY TELESCOPE: COSMOLOGICAL PARAMETERS FROM THE 2008 POWER SPECTRUMJ. Dunkley, R. Hlozek, J. Sievers et al. IMPROVED CONSTRAINTS ON COSMIC MICROWAVE BACKGROUND SECONDARY ANISOTROPIES FROMSOUTH THE POLE COMPLETE TELESCOPE 2008 DATA E. Shirokoff, C. L. Reichardt, L. Shaw et al. A MEASUREMENT OF SECONDARY COSMIC MICROWAVE BACKGROUND ANISOTROPIES WITH TWO YEARSTELESCOPE OF SOUTH OBSERVATIONS POLE C. L. Reichardt, L. Shaw, O. Zahn et al. A MEASUREMENT OF SECONDARY COSMIC MICROWAVE BACKGROUND ANISOTROPIES FROM THE 2500SPT-SZ SQUARE-DEGREE SURVEY E. M. George, C. L. Reichardt, K. A. Aird et al. MODELING EXTRAGALACTIC FOREGROUNDS AND SECONDARIES FOR UNBIASED ESTIMATION OF COSMOLOGICALPARAMETERS FROM PRIMARY COSMIC MICROWAVE BACKGROUND ANISOTROPY M. Millea, O. Doré, J. Dudley et al. MEASUREMENTS OF SECONDARY CMB ANISOTROPIES WITH SPT M. Lueker, C. L. Reichardt, K. K. Schaffer et al. ANGULAR POWER SPECTRA OF THE mm-WAVELENGTH BACKGROUND LIGHT N. R.
    [Show full text]
  • Management Plan for Antarctic Specially Managed Area No.5 AMUNDSEN-SCOTT SOUTH POLE STATION, SOUTH POLE
    Measure 8 (2017) Management Plan for Antarctic Specially Managed Area No.5 AMUNDSEN-SCOTT SOUTH POLE STATION, SOUTH POLE Introduction The Amundsen-Scott South Pole Station (hereafter referred to as South Pole Station), operated by the United States, is located on the polar plateau at an elevation of 2835 m near the geographic South Pole at 90°S. An area of ~26,344 km2 around the South Pole Station is designated as an Antarctic Specially Managed Area (hereafter referred to as ‘the Area’). The Area has been designated in order to maximize the valuable scientific opportunities at the Pole, protect the near-pristine environment and ensure that all activities, including those to experience the extraordinary qualities of the South Pole, can be conducted safely, environmentally responsibly and without disruption to scientific programs. In order to help achieve the objectives of the Management Plan, the Area has been divided into Scientific, Operations, and Restricted zones. The Scientific Zone is further divided into four sectors: Clean Air, Quiet, Downwind and Dark. The management measures agreed for those areas help coordinate activities and protect the important values of the South Pole. The Area was originally designated following a proposal by the United States of America and adopted through Measure 2 (2007). The current Management Plan has been comprehensively revised and updated as part of the review process required by the Protocol on Environmental Protection to the Antarctic Treaty (hereafter the Protocol). The Area is situated within ‘Environment Q – East Antarctic high interior ice sheet’, as defined in the Environmental Domains Analysis for Antarctica (Resolution 3 (2008)).
    [Show full text]
  • Inner Workings: Probing Cosmic Mysteries in a Remote Desert Amber Dance Science Writer Ever, Deciphering That Signal Is Not Always Straightforward
    INNER WORKINGS INNER WORKINGS Inner Workings: Probing cosmic mysteries in a remote desert Amber Dance Science Writer ever, deciphering that signal is not always straightforward. In 2014, the researchers on the Background Imaging of Cosmic Extra- Amidthevolcanicrangeofthewindy,oth- proof remains elusive. “All of a sudden, galactic Polarization (BICEP) experiment erworldly Atacama Desert, a telescope collects whoosh, inflation occurred, an exponen- thought they had evidence for inflation; ancient light from the cloudless sky. The tial expansion of space,” says Adrian Lee later physicists determined the signal likely international team of cosmologists manning of the University of California, Berkeley, prin- came from dust in the Milky Way (1, 2). ’ the instrument hopes it will illuminate the cipal investigator on the US portion of the Lee s project got the moniker POLAR- conditions of the universe just after its dawn project. “What we’re looking for is really a BEARaswordplayforwhatithopesto 13.8 billion years ago. signal from the beginning of time.” detect: “POLARization of the Background Most physicists believe that the universe The signal, if it exists, should show up in Radiation.” Swirling patterns in the direction inflated rapidly, just a fraction of a nanosecond the primordial light waves called cosmic mi- of polarization should not only offer up a after it came into being, although definitive crowave background radiation (CMB). How- clincher for inflation, if it occurred, but also The POLARBEAR telescope in Chile’s Atacama Desert aims to reveal the nature of neutrinos and the origins of the universe. Image courtesy of Adrian Lee. www.pnas.org/cgi/doi/10.1073/pnas.1509007112 PNAS | July 14, 2015 | vol.
    [Show full text]
  • Galaxy Clusters Selected Via the Sunyaev–Zel'dovich Effect in The
    Draft version January 15, 2020 Typeset using LATEX twocolumn style in AASTeX63 Galaxy Clusters Selected via the Sunyaev-Zel'dovich Effect in the SPTpol 100-Square-Degree Survey N. Huang,1 L. E. Bleem,2, 3 B. Stalder,4, 5 P. A. R. Ade,6 S. W. Allen,7, 8, 9 A. J. Anderson,10 J. E. Austermann,11 J. S. Avva,1 J. A. Beall,11 A. N. Bender,2, 3 B. A. Benson,10, 3, 12 F. Bianchini,13 S. Bocquet,14, 2, 3 M. Brodwin,15 J. E. Carlstrom,3, 16, 2, 12, 17 C. L. Chang,3, 2, 12 H. C. Chiang,18, 19 R. Citron,20 C. Corbett Moran,20, 21 T. M. Crawford,3, 12 A. T. Crites,3, 12, 22 T. de Haan,1, 23 M. A. Dobbs,18, 24 W. Everett,25 B. Floyd,15 J. Gallicchio,3, 26 E. M. George,27, 1 A. Gilbert,18 M. D. Gladders,12, 3 S. Guns,1 N. Gupta,13 N. W. Halverson,25, 28 N. Harrington,1 J. W. Henning,2, 3 G. C. Hilton,11 G. P. Holder,29, 30, 24 W. L. Holzapfel,1 J. D. Hrubes,20 J. Hubmayr,11 K. D. Irwin,9, 31 G. Khullar,3, 12 L. Knox,32 A. T. Lee,1, 23 D. Li,11, 9 A. Lowitz,12 M. McDonald,33 J. J. McMahon,34 S. S. Meyer,3, 16, 12, 17 L. M. Mocanu,12, 3, 35 J. Montgomery,18 A. Nadolski,30, 29 T. Natoli,12, 3, 36 J. P. Nibarger,11 G.
    [Show full text]