Small-Scale Anisotropies of the Cosmic Microwave Background: Experimental and Theoretical Perspectives
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High-Energy Astrophysics
High-Energy Astrophysics Andrii Neronov October 30, 2017 2 Contents 1 Introduction 5 1.1 Types of astronomical HE sources . .7 1.2 Types of physical processes involved . .8 1.3 Observational tools . .9 1.4 Natural System of Units . 11 1.5 Excercises . 14 2 Radiative Processes 15 2.1 Radiation from a moving charge . 15 2.2 Curvature radiation . 17 2.2.1 Astrophysical example (pulsar magnetosphere) . 19 2.3 Evolution of particle distribution with account of radiative energy loss . 20 2.4 Spectrum of emission from a broad-band distribution of particles . 21 2.5 Cyclotron emission / absorption . 23 2.5.1 Astrophysical example (accreting pulsars) . 23 2.6 Synchrotron emission . 24 2.6.1 Astrophysical example (Crab Nebula) . 26 2.7 Compton scattering . 28 2.7.1 Thomson cross-section . 28 2.7.2 Example: Compton scattering in stars. Optical depth of the medium. Eddington luminosity 30 2.7.3 Angular distribution of scattered waves . 31 2.7.4 Thomson scattering . 32 2.7.5 Example: Compton telescope(s) . 33 2.8 Inverse Compton scattering . 34 2.8.1 Energies of upscattered photons . 34 2.8.2 Energy loss rate of electron . 35 2.8.3 Evolution of particle distribution with account of radiative energy loss . 36 2.8.4 Spectrum of emission from a broad-band distribution of particles . 36 2.8.5 Example: Very-High-Energy gamma-rays from Crab Nebula . 37 2.8.6 Inverse Compton scattering in Klein-Nishina regime . 37 2.9 Bethe-Heitler pair production . 38 2.9.1 Example: pair conversion telescopes. -
Detection of Polarization in the Cosmic Microwave Background Using DASI
Detection of Polarization in the Cosmic Microwave Background using DASI Thesis by John M. Kovac A Dissertation Submitted to the Faculty of the Division of the Physical Sciences in Candidacy for the Degree of Doctor of Philosophy The University of Chicago Chicago, Illinois 2003 Copyright c 2003 by John M. Kovac ° (Defended August 4, 2003) All rights reserved Acknowledgements Abstract This is a sample acknowledgement section. I would like to take this opportunity to The past several years have seen the emergence of a new standard cosmological model thank everyone who contributed to this thesis. in which small temperature di®erences in the cosmic microwave background (CMB) I would like to take this opportunity to thank everyone. I would like to take on degree angular scales are understood to arise from acoustic oscillations in the hot this opportunity to thank everyone. I would like to take this opportunity to thank plasma of the early universe, sourced by primordial adiabatic density fluctuations. In everyone. the context of this model, recent measurements of the temperature fluctuations have led to profound conclusions about the origin, evolution and composition of the uni- verse. Given knowledge of the temperature angular power spectrum, this theoretical framework yields a prediction for the level of the CMB polarization with essentially no free parameters. A determination of the CMB polarization would therefore provide a critical test of the underlying theoretical framework of this standard model. In this thesis, we report the detection of polarized anisotropy in the Cosmic Mi- crowave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. -
Optical SETI: the All-Sky Survey
Professor van der Veen Project Scientist, UCSB Department of Physics, Experimental Cosmology Group class 4 [email protected] frequencies/wavelengths that get through the atmosphere The Planetary Society http://www.planetary.org/blogs/jason-davis/2017/20171025-seti-anybody-out-there.html THE ATMOSPHERE'S EFFECT ON ELECTROMAGNETIC RADIATION Earth's atmosphere prevents large chunks of the electromagnetic spectrum from reaching the ground, providing a natural limit on where ground-based observatories can search for SETI signals. Searching for technology that we have, or are close to having: Continuous radio searches Pulsed radio searches Targeted radio searches All-sky surveys Optical: Continuous laser and near IR searches Pulsed laser searches a hypothetical laser beacon watch now: https://www.youtube.com/watch?time_continue=41&v=zuvyhxORhkI Theoretical physicist Freeman Dyson’s “First Law of SETI Investigations:” Every search for alien civilizations should be planned to give interesting results even when no aliens are discovered. Interview with Carl Sagan from 1978: Start at 6:16 https://www.youtube.com/watch?v=g- Q8aZoWqF0&feature=youtu.be Anomalous signal recorded by Big Ear Telescope at Ohio State University. Big Ear was a flat, aluminum dish three football fields wide, with reflectors at both ends. Signal was at 1,420 MHz, the hydrogen 21 cm ‘spin flip’ line. http://www.bigear.org/Wow30th/wow30th.htm May 15, 2015 A Russian observatory reports a strong signal from a Sun-like star. Possibly from advanced alien civilization. The RATAN-600 radio telescope in Zelenchukskaya, at the northern foot of the Caucasus Mountains location: star HD 164595 G-type star (like our Sun) 94.35 ly away, visually located in constellation Hercules 1 planet that orbits it every 40 days unusual radio signal detected – 11 GHz (2.7 cm) claim: Signal from a Type II Kardashev civilization Only one observation Not confirmed by other telescopes Russian Academy of Sciences later retracted the claim that it was an ETI signal, stating the signal came from a military satellite. -
Introduction to Temperature Anisotropies of Cosmic Microwave Background Radiation
Prog. Theor. Exp. Phys. 2014, 06B101 (13 pages) DOI: 10.1093/ptep/ptu073 CMB Cosmology Introduction to temperature anisotropies of Cosmic Microwave Background radiation Naoshi Sugiyama1,2,3,∗ 1Department of Physics, Nagoya University, Nagoya, 464-8602, Japan 2Kobayashi Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya, Japan 3Kavli IPMU, University of Tokyo, Japan ∗E-mail: [email protected] Received April 7, 2014; Revised April 28, 2014; Accepted April 30, 2014; Published June 11 , 2014 Downloaded from ............................................................................... Since its serendipitous discovery, Cosmic Microwave Background (CMB) radiation has been recognized as the most important probe of Big Bang cosmology. This review focuses on temper- ature anisotropies of CMB which make it possible to establish precision cosmology. Following a brief history of CMB research, the physical processes working on the evolution of CMB http://ptep.oxfordjournals.org/ anisotropies are discussed, including gravitational redshift, acoustic oscillations, and diffusion dumping. Accordingly, dependencies of the angular power spectrum on various cosmological parameters, such as the baryon density, the matter density, space curvature of the universe, and so on, are examined and intuitive explanations of these dependencies are given. ............................................................................... Subject Index E56, E60, E63, E65 by guest on June 19, 2014 1. Introduction: A brief history of research on CMB Since its serendipitous discovery in 1965 by Penzias and Wilson [1], Cosmic Microwave Background (CMB) radiation, which was first predicted by Alpher and Herman in 1948 [2] as radiation at 5 Kat the present time, has become one of the most important observational probes of Big Bang cosmology. CMB is recognized as a fossil of the early universe because it directly brings information from the epoch of recombination, which is 370, 000 years after the beginning of the universe. -
A CMB Polarization Primer
New Astronomy 2 (1997) 323±344 A CMB polarization primer Wayne Hua,1,2 , Martin White b,3 aInstitute for Advanced Study, Princeton, NJ 08540, USA bEnrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA Received 13 June 1997; accepted 30 June 1997 Communicated by David N. Schramm Abstract We present a pedagogical and phenomenological introduction to the study of cosmic microwave background (CMB) polarization to build intuition about the prospects and challenges facing its detection. Thomson scattering of temperature anisotropies on the last scattering surface generates a linear polarization pattern on the sky that can be simply read off from their quadrupole moments. These in turn correspond directly to the fundamental scalar (compressional), vector (vortical), and tensor (gravitational wave) modes of cosmological perturbations. We explain the origin and phenomenology of the geometric distinction between these patterns in terms of the so-called electric and magnetic parity modes, as well as their correlation with the temperature pattern. By its isolation of the last scattering surface and the various perturbation modes, the polarization provides unique information for the phenomenological reconstruction of the cosmological model. Finally we comment on the comparison of theory with experimental data and prospects for the future detection of CMB polarization. 1997 Elsevier Science B.V. PACS: 98.70.Vc; 98.80.Cq; 98.80.Es Keywords: Cosmic microwave background; Cosmology: theory 1. Introduction scale structure we see today. If the temperature anisotropies we observe are indeed the result of Why should we be concerned with the polarization primordial ¯uctuations, their presence at last scatter- of the cosmic microwave background (CMB) ing would polarize the CMB anisotropies them- anisotropies? That the CMB anisotropies are polar- selves. -
Looking at Earth: an Astronaut's Journey Induction Ceremony 2017
american academy of arts & sciences winter 2018 www.amacad.org Bulletin vol. lxxi, no. 2 Induction Ceremony 2017 Class Speakers: Jane Mayer, Ursula Burns, James P. Allison, Heather K. Gerken, and Gerald Chan Annual David M. Rubenstein Lecture Looking at Earth: An Astronaut’s Journey David M. Rubenstein and Kathryn D. Sullivan ALSO: How Are Humans Different from Other Great Apes?–Ajit Varki, Pascal Gagneux, and Fred H. Gage Advancing Higher Education in America–Monica Lozano, Robert J. Birgeneau, Bob Jacobsen, and Michael S. McPherson Redistricting and Representation–Patti B. Saris, Gary King, Jamal Greene, and Moon Duchin noteworthy Select Prizes and Andrea Bertozzi (University of James R. Downing (St. Jude Chil- Barbara Grosz (Harvard Univer- California, Los Angeles) was se- dren’s Research Hospital) was sity) is the recipient of the Life- Awards to Members lected as a 2017 Simons Investi- awarded the 2017 E. Donnall time Achievement Award of the gator by the Simons Foundation. Thomas Lecture and Prize by the Association for Computational American Society of Hematology. Linguistics. Nobel Prize in Chemistry, Clara D. Bloomfield (Ohio State 2017 University) is the recipient of the Carol Dweck (Stanford Univer- Christopher Hacon (University 2017 Robert A. Kyle Award for sity) was awarded the inaugural of Utah) was awarded the Break- Joachim Frank (Columbia Univer- Outstanding Clinician-Scientist, Yidan Prize. through Prize in Mathematics. sity) presented by the Mayo Clinic Di- vision of Hematology. Felton Earls (Harvard Univer- Naomi Halas (Rice University) sity) is the recipient of the 2018 was awarded the 2018 Julius Ed- Nobel Prize in Economic Emmanuel J. -
Radio and Millimeter Continuum Surveys and Their Astrophysical Implications
The Astronomy and Astrophysics Review (2011) DOI 10.1007/s00159-009-0026-0 REVIEWARTICLE Gianfranco De Zotti · Marcella Massardi · Mattia Negrello · Jasper Wall Radio and millimeter continuum surveys and their astrophysical implications Received: 13 May 2009 c Springer-Verlag 2009 Abstract We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determina- tions of local luminosity functions are presented and compared with earlier esti- mates still in widespread use. A number of unresolved issues are discussed. These include: the (possibly luminosity-dependent) decline of source space densities at high redshifts; the possible dichotomies between evolutionary properties of low- versus high-luminosity and of flat- versus steep-spectrum AGN-powered radio sources; and the nature of sources accounting for the upturn of source counts at sub-milli-Jansky (mJy) levels. It is shown that straightforward extrapolations of evolutionary models, accounting for both the far-IR counts and redshift distribu- tions of star-forming galaxies, match the radio source counts at flux-density levels of tens of µJy remarkably well. We consider the statistical properties of rare but physically very interesting classes of sources, such as GHz Peak Spectrum and ADAF/ADIOS sources, and radio afterglows of γ-ray bursts. We also discuss the exploitation of large-area radio surveys to investigate large-scale structure through studies of clustering and the Integrated Sachs–Wolfe effect. Finally, we briefly describe the potential of the new and forthcoming generations of radio telescopes. A compendium of source counts at different frequencies is given in Supplemen- tary Material. -
Arxiv:2008.11688V1 [Astro-Ph.CO] 26 Aug 2020
APS/123-QED Cosmology with Rayleigh Scattering of the Cosmic Microwave Background Benjamin Beringue,1 P. Daniel Meerburg,2 Joel Meyers,3 and Nicholas Battaglia4 1DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, UK, CB3 0WA 2Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands 3Department of Physics, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas 75275, USA 4Department of Astronomy, Cornell University, Ithaca, New York, USA (Dated: August 27, 2020) The cosmic microwave background (CMB) has been a treasure trove for cosmology. Over the next decade, current and planned CMB experiments are expected to exhaust nearly all primary CMB information. To further constrain cosmological models, there is a great benefit to measuring signals beyond the primary modes. Rayleigh scattering of the CMB is one source of additional cosmological information. It is caused by the additional scattering of CMB photons by neutral species formed during recombination and exhibits a strong and unique frequency scaling ( ν4). We will show that with sufficient sensitivity across frequency channels, the Rayleigh scattering/ signal should not only be detectable but can significantly improve constraining power for cosmological parameters, with limited or no additional modifications to planned experiments. We will provide heuristic explanations for why certain cosmological parameters benefit from measurement of the Rayleigh scattering signal, and confirm these intuitions using the Fisher formalism. In particular, observation of Rayleigh scattering P allows significant improvements on measurements of Neff and mν . PACS numbers: Valid PACS appear here I. INTRODUCTION direction of propagation of the (primary) CMB photons. There are various distinguishable ways that cosmic In the current era of precision cosmology, the Cosmic structures can alter the properties of CMB photons [10]. -
Cosmology After WMAP (5)
Cosmology After WMAP (5) DavidDavid SpergelSpergel Geneve June 2008 StandardStandard cosmologicalcosmological modelmodel StillStill FitsFits thethe DataData ! General Relativity + Uniform Universe Big Bang " Density of universe determines its fate + shape ! Universe is flat (total density = critical density) " Atoms 4% " Dark Matter 23% " Dark Energy (cosmological constant?) 72% ! Universe has tiny ripples " Adiabatic, scale invariant, Gaussian Fluctuations " Harrison-Zeldovich-Peebles " Inflationary models QuickQuick HistoryHistory ofof thethe UniverseUniverse " Universe starts out hot, dense and filled with radiation " As the universe expands, it cools. • During the first minutes, light elements form • After 500,000 years, atoms form • After 100,000,000 years, stars start to form • After 1 Billion years, galaxies and quasars ThermalThermal HistoryHistory ofof UniverseUniverse radiation matter NEUTRAL r IONIZED 104 103 z GrowthGrowth ofof FluctuationsFluctuations •Linear theory •Basic elements have been understood for 30 years (Peebles, Sunyaev & Zeldovich) •Numerical codes agree at better than 0.1% (Seljak et al. 2003) Sunyaev & Zeldovich CMBCMB OverviewOverview ! We can detect both CMB temperature and polarization fluctuations ! Polarization Fluctuations can be decomposed into E and B modes q ~180/l ADIABATIC DENSITY FLUCTUATIONS ISOCURVATURE ENTROPY FLUCTUATIONS DeterminingDetermining BasicBasic ParametersParameters Baryon Density 2 Wbh = 0.015,0.017..0.031 also measured through D/H DeterminingDetermining BasicBasic ParametersParameters -
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. -
The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation
Brigham Young University BYU ScholarsArchive Theses and Dissertations 2005-09-05 The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation Jacob L. Campbell Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd Part of the Electrical and Computer Engineering Commons BYU ScholarsArchive Citation Campbell, Jacob L., "The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation" (2005). Theses and Dissertations. 673. https://scholarsarchive.byu.edu/etd/673 This Thesis is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. THE DEVELOPMENT OF A SMALL SCALE RADIO ASTRONOMY IMAGE SYNTHESIS ARRAY FOR RESEARCH IN RADIO FREQUENCY INTERFERENCE MITIGATION by Jacob Lee Campbell A thesis submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Master of Science Department of Electrical and Computer Engineering Brigham Young University December 2005 Copyright c 2005 Jacob Lee Campbell All Rights Reserved BRIGHAM YOUNG UNIVERSITY GRADUATE COMMITTEE APPROVAL of a thesis submitted by Jacob Lee Campbell This thesis has been read by each member of the following graduate committee and by majority vote has -
Controlling and Leveraging Small-Scale Information in Tomographic Galaxy-Galaxy Lensing
MNRAS 000,1{13 (2015) Preprint 19 March 2019 Compiled using MNRAS LATEX style file v3.0 Controlling and leveraging small-scale information in tomographic galaxy-galaxy lensing Niall MacCrann1;2?, Jonathan Blazek3, Bhuvnesh Jain4 and Elisabeth Krause5 1 Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210, USA 2 Department of Physics, The Ohio State University, Columbus, OH 43210, USA 3 Institute of Physics, Laboratory of Astrophysics, Ecole´ Polytechnique F´ed´erale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA 5 Department of Astronomy/Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT The tangential shear signal receives contributions from physical scales in the galaxy- matter correlation function well below the transverse scale at which it is measured. Since small scales are difficult to model, this non-locality has generally required strin- gent scale cuts or new statistics for cosmological analyses. Using the fact that uncer- tainty in these contributions corresponds to an uncertainty in the enclosed projected mass around the lens, we provide an analytic marginalization scheme to account for this. Our approach enables the inclusion of measurements on smaller scales with- out requiring numerical sampling over extra free parameters. We extend the analytic marginalization formalism to retain cosmographic (\shear-ratio") information from small-scale measurements that would otherwise be removed due to modeling uncer- tainties, again without requiring the addition of extra sampling parameters. We test the methodology using simulated likelihood analysis of a DES Year 5-like galaxy- galaxy lensing and galaxy clustering datavector.