Anisotropies of the Cosmic Microwave Background 3
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
UNIVERSIT`A DEGLI STUDI DI TRIESTE Using Hydrodynamical
UNIVERSITA` DEGLI STUDI DI TRIESTE Facolt`adi Scienze Matematiche, Fisiche e Naturali Dottorato di Ricerca in Fisica - XX Ciclo Using hydrodynamical simulations to combine Sunyaev–Zeldovich and X–ray studies of galaxy clusters DOTTORANDA COORDINATORE DEL COLLEGIO DEI DOCENTI Silvia Ameglio Chiar.mo Prof. Gaetano Senatore, Universit`adi Trieste TUTORE Chiar.mo Prof. Stefano Borgani, Universit`adi Trieste RELATORE Chiar.mo Prof. Stefano Borgani, Universit`adi Trieste a.a. 2006/2007 Contents 1 Introduction 1 2 Clusters of galaxies: an overview 5 2.1 X–rayemission ................................. 6 2.2 The Sunyaev–Zeldovich effect (SZ) . ... 8 2.2.1 The thermal Sunyaev–Zeldovich effect (tSZ) . .... 8 2.2.2 The kinetic Sunyaev–Zeldovich effect . 11 2.3 Statusofobservations . .. .. .. .. .. .. .. .. 11 2.3.1 X–rays.................................. 11 2.3.2 The Sunyaev–Zeldovich effect . 17 2.4 Cosmology with galaxy clusters . 23 2.5 Conclusions ................................... 29 3 Hydrodynamical simulations of galaxy clusters 31 3.1 The gravitational dynamics: the N–body TREE code . ...... 31 3.2 The gas physics: Smoothed Particle Hydrodynamics (SPH) ........ 33 3.3 Thesetofsimulatedclusters . 35 3.3.1 Thermal processes in the IntraCluster Medium (ICM) . ..... 38 3.3.2 The sample of simulated clusters . 40 3.3.3 Generation of tSZ, X–ray and temperature maps . 41 3.4 Definitionsoftemperature. 45 4 The angular diameter distance measurement 51 4.1 The polytropic β–model ............................ 53 4.2 DA from combined X-ray and tSZ observations . 53 4.3 Results...................................... 55 4.3.1 Resultsfromtheisothermalmodel . 55 4.3.2 Resultsfromthepolytropicfit . 57 4.3.3 Implications for cosmological parameters . ...... 60 4.4 Conclusions .................................. -
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. -
Analysis and Measurement of Horn Antennas for CMB Experiments
Analysis and Measurement of Horn Antennas for CMB Experiments Ian Mc Auley (M.Sc. B.Sc.) A thesis submitted for the Degree of Doctor of Philosophy Maynooth University Department of Experimental Physics, Maynooth University, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland. October 2015 Head of Department Professor J.A. Murphy Research Supervisor Professor J.A. Murphy Abstract In this thesis the author's work on the computational modelling and the experimental measurement of millimetre and sub-millimetre wave horn antennas for Cosmic Microwave Background (CMB) experiments is presented. This computational work particularly concerns the analysis of the multimode channels of the High Frequency Instrument (HFI) of the European Space Agency (ESA) Planck satellite using mode matching techniques to model their farfield beam patterns. To undertake this analysis the existing in-house software was upgraded to address issues associated with the stability of the simulations and to introduce additional functionality through the application of Single Value Decomposition in order to recover the true hybrid eigenfields for complex corrugated waveguide and horn structures. The farfield beam patterns of the two highest frequency channels of HFI (857 GHz and 545 GHz) were computed at a large number of spot frequencies across their operational bands in order to extract the broadband beams. The attributes of the multimode nature of these channels are discussed including the number of propagating modes as a function of frequency. A detailed analysis of the possible effects of manufacturing tolerances of the long corrugated triple horn structures on the farfield beam patterns of the 857 GHz horn antennas is described in the context of the higher than expected sidelobe levels detected in some of the 857 GHz channels during flight. -
La Radiación Del Fondo Cósmico De Microondas Abstracts
Simposio Internacional: La radiación del Fondo Cósmico de Microondas: mensajera de los orígenes del universo International Symposium: CMB Radiation: Messenger of the Origins of Our Universe Madrid, 6 de noviembre de 2014 Madrid, November 6, 2014 I The seeds of structure: A view of the Cosmic Microwave Background, Joseph Silk The shape of the universe as seen by Planck, Enrique Martínez-González Deciphering the beginnings of the universe with CMB polarization, Matías Zaldarriaga 30 years of Cosmic Microwave Background experiments in Tenerife: From temperature to polarization maps, Rafael Rebolo Cosmology from Planck: Do we need a new Physics?, Nazzareno Mandolesi FUNDACIÓN RAMÓN ARECES Simposio Internacional: La radiación del Fondo Cósmico de Microondas: mensajera de los orígenes del universo International Symposium: CMB Radiation: Messenger of the Origins of Our Universe Madrid, 6 de noviembre de 2014 Madrid, November 6, 2014 The seeds of structure: A view of the Cosmic Microwave Background, Joseph Silk One of our greatest challenges is understanding the origin of the structure of the universe.I will describe how the fossil radiation from the beginning of the universe, the cosmic microwave background, has provided a window for probing the initial conditions from which structure evolved. Infinitesimal variations in temperature on the sky, first discovered in 1992, provide the fossil fluctuations that seeded the formation of the galaxies. The cosmic microwave background radiation has now been mapped with ground-based, balloon-borne and satellite telescopes. These provide the basis for our current ``precision cosmology'' in which the universe not only contains Dark Matter but also ``DarkEnergy'', which has accelerated its expansion exponentially in the last 4 billion years. -
2006-2007 Science Planning Summaries
Project Indexes Find information about projects approved for the 2006-2007 USAP field season using the available indexes. Project Web Sites Find more information about 2006-2007 USAP projects by viewing project web sites. More Information Additional information pertaining to the 2006-2007 Field Season. Home Page Station Schedules Air Operations Staffed Field Camps Event Numbering System 2006-2007 USAP Field Season Project Indexes Project Indexes Find information about projects approved for the 2006-2007 USAP field season using the USAP Program Indexes available indexes. Aeronomy and Astrophysics Dr. Bernard Lettau, Program Director (acting) Project Web Sites Biology and Medicine Dr. Roberta Marinelli, Program Director Find more information about 2006-2007 USAP projects by Geology and Geophysics viewing project web sites. Dr. Thomas Wagner, Program Director Glaciology Dr. Julie Palais, Program Director More Information Ocean and Climate Systems Additional information pertaining Dr. Bernhard Lettau, Program Director to the 2006-2007 Field Season. Artists and Writers Home Page Ms. Kim Silverman, Program Director Station Schedules USAP Station and Vessel Indexes Air Operations Staffed Field Camps Amundsen-Scott South Pole Station Event Numbering System McMurdo Station Palmer Station RVIB Nathaniel B. Palmer ARSV Laurence M. Gould Special Projects Principal Investigator Index Deploying Team Members Index Institution Index Event Number Index Technical Event Index Project Web Sites 2006-2007 USAP Field Season Project Indexes Project Indexes Find information about projects approved for the 2006-2007 USAP field season using the Project Web Sites available indexes. Principal Investigator/Link Event No. Project Title Aghion, Anne W-218-M Works and days: An antarctic Project Web Sites chronicle Find more information about 2006-2007 USAP projects by Ainley, David B-031-M Adélie penguin response to viewing project web sites. -
A Bayesian Method for Point Source Polarisation Estimation D
A&A 651, A24 (2021) Astronomy https://doi.org/10.1051/0004-6361/202039741 & c ESO 2021 Astrophysics A Bayesian method for point source polarisation estimation D. Herranz1, F. Argüeso2,4, L. Toffolatti3,4, A. Manjón-García1,5, and M. López-Caniego6 1 Instituto de Física de Cantabria, CSIC-UC, Av. de Los Castros s/n, 39005 Santander, Spain e-mail: [email protected] 2 Departamento de Matemáticas, Universidad de Oviedo, C. Federico García Lorca 18, 33007 Oviedo, Spain 3 Departamento de Física, Universidad de Oviedo, C. Federico García Lorca 18, 33007 Oviedo, Spain 4 Instituto Universitario de Ciencias y Tecnologías Espaciales de Asturias (ICTEA), Escuela de Ingeniería de Minas, Materiales y Energía de Oviedo, C. Independencia 13, 33004 Oviedo, Spain 5 Departamento de Física Moderna, Universidad de Cantabria, 39005 Santander, Spain 6 ESAC, Camino Bajo del Castillo s/n, 28692 Villafranca del Castillo, Madrid, Spain Received 22 October 2020 / Accepted 2 March 2021 ABSTRACT The estimation of the polarisation P of extragalactic compact sources in cosmic microwave background (CMB) images is a very important task in order to clean these images for cosmological purposes –for example, to constrain the tensor-to-scalar ratio of primordial fluctuations during inflation– and also to obtain relevant astrophysical information about the compact sources themselves in a frequency range, ν ∼ 10–200 GHz, where observations have only very recently started to become available. In this paper, we propose a Bayesian maximum a posteriori approach estimation scheme which incorporates prior information about the distribution of the polarisation fraction of extragalactic compact sources between 1 and 100 GHz. -
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. -
Observational Cosmology - 30H Course 218.163.109.230 Et Al
Observational cosmology - 30h course 218.163.109.230 et al. (2004–2014) PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Thu, 31 Oct 2013 03:42:03 UTC Contents Articles Observational cosmology 1 Observations: expansion, nucleosynthesis, CMB 5 Redshift 5 Hubble's law 19 Metric expansion of space 29 Big Bang nucleosynthesis 41 Cosmic microwave background 47 Hot big bang model 58 Friedmann equations 58 Friedmann–Lemaître–Robertson–Walker metric 62 Distance measures (cosmology) 68 Observations: up to 10 Gpc/h 71 Observable universe 71 Structure formation 82 Galaxy formation and evolution 88 Quasar 93 Active galactic nucleus 99 Galaxy filament 106 Phenomenological model: LambdaCDM + MOND 111 Lambda-CDM model 111 Inflation (cosmology) 116 Modified Newtonian dynamics 129 Towards a physical model 137 Shape of the universe 137 Inhomogeneous cosmology 143 Back-reaction 144 References Article Sources and Contributors 145 Image Sources, Licenses and Contributors 148 Article Licenses License 150 Observational cosmology 1 Observational cosmology Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors. Early observations The science of physical cosmology as it is practiced today had its subject material defined in the years following the Shapley-Curtis debate when it was determined that the universe had a larger scale than the Milky Way galaxy. This was precipitated by observations that established the size and the dynamics of the cosmos that could be explained by Einstein's General Theory of Relativity. -
The QUIJOTE Experiment: Project Overview and First Results
Highlights of Spanish Astrophysics VIII, Proceedings of the XI Scientific Meeting of the Spanish Astronomical Society held on September 8–12, 2014, in Teruel, Spain. A. J. Cenarro, F. Figueras, C. Hernández-Monteagudo, J. Trujillo Bueno, and L. Valdivielso (eds.) The QUIJOTE experiment: project overview and first results R. G´enova-Santos1;6, J. A. Rubi~no-Mart´ın1;6, R. Rebolo1;6;7, M. Aguiar1, F. G´omez-Re~nasco1, C. Guti´errez1;6, R. J. Hoyland1, C. L´opez-Caraballo1;6;8, A. E. Pel´aez-Santos1;6, M. R. P´erez-de-Taoro1, F. Poidevin1;6 , V. S´anchez de la Rosa1, D. Tramonte1;6, A. Vega-Moreno1, T. Viera-Curbelo1, R. Vignaga1;6, E. Mart´ınez-Gonz´alez2, R. B. Barreiro2, B. Casaponsa2, F. J. Casas2, J. M. Diego2, R. Fern´andez-Cobos2, D. Herranz2, M. L´opez-Caniego2, D. Ortiz2, P. Vielva2, E. Artal3, B. Aja3, J. Cagigas3, J. L. Cano3, L. de la Fuente3, A. Mediavilla3, J. V. Ter´an3, E. Villa3, L. Piccirillo4, R. Davies4, R. J. Davis4, C. Dickinson4, K. Grainge4, S. Harper4, B. Maffei4, M. McCulloch4, S. Melhuish4, G. Pisano4, R. A. Watson4, A. Lasenby5;9, M. Ashdown5;9, M. Hobson5, Y. Perrott5, N. Razavi-Ghods5, R. Saunders6, D. Titterington6 and P. Scott6 1 Instituto de Astrofis´ıcade Canarias, 38200 La Laguna, Tenerife, Canary Islands, Spain 2 Instituto de F´ısicade Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, 39005 Santander, Spain 3 Departamento de Ingenieria de COMunicaciones (DICOM), Laboratorios de I+D de Telecomunicaciones, Universidad de Cantabria, Plaza de la Ciencia s/n, E-39005 Santander, Spain 4 Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K 5 Astrophysics Group, Cavendish Laboratory, University of Cambridge, J.J. -
National Science Foundation
This document has been archived. National Science Foundation U.S. Antarctic Program 1999-2000 National Science Foundation U.S. Antarctic Program 1999-2000 i CONTENTS U.S. Antarctic Program, 1999-2000 . .ii Aeronomy and Astrophysics . 1 Biology and Medicine . 12 Antarctic Pack Ice Seals . 25 Long-term ecological research . 28 Environmental Monitoring Program . 31 Geology and Geophysics . 32 Cape Roberts International Drilling Project . 47 Glaciology . 51 Siple Dome Ice Coring . 55 International Trans-Antarctic Scientific Expedition . 57 Ocean and Climate Systems . 60 ii During the 1999-2000 austral summer and the Station by a team of scientists from the PROGRAM,U.S. ANTARCTIC 1999-2000 2000 austral winter, the U.S. Antarctic Program United States, New Zealand, Italy, Australia, will support more than 800 researchers and the United Kingdom, and Germany other participants in the U.S. Antarctic Program • long-term ecological research in the at three year-round stations (McMurdo, McMurdo Dry Valleys and in the Palmer Amundsen-Scott South Pole, and Palmer), Station region of the Antarctic Peninsula aboard two research ships (Laurence M. Gould and Nathaniel B. Palmer) in the Ross Sea and in Science teams also will use networks of the Antarctic Peninsula region, at remote field automatic weather stations, automated geo- camps, and in cooperation with the national physical observatories, ultraviolet-radiation antarctic programs of the other Antarctic Treaty monitors, and a high-altitude, long-duration nations. These projects, funded and managed balloon that will circumnavigate the continent by the National Science Foundation (NSF), are and carry instruments for an optical investiga- part of the international effort to understand tion of solar activity. -
Quasi-Optical Design and Analysis of a Bolometric Interferometer for Cosmic Microwave Background Radiation Experiments
Quasi-Optical Design and Analysis of a Bolometric Interferometer for Cosmic Microwave Background Radiation Experiments Maynooth University Department of Experimental Physics Stephen Scully BSc (Eng) HDip (App Phy) A thesis submitted for the degree of Doctor of Philosophy February 2016 Department Head Prof. J. Anthony Murphy Supervisor Dr. Créidhe O’Sullivan TABLE OF CONTENTS 1 INTRODUCTION ....................................................................................................................... 1 1.1 COSMOLOGY AND THE CMB ........................................................................................................ 1 1.1.1 Historical........................................................................................................................... 1 1.1.2 The Big Bang Theory ......................................................................................................... 3 1.1.3 Inflation ............................................................................................................................ 7 1.1.4 Angular power spectrum of the CMB ............................................................................... 7 1.2 MEASURING THE CMB ............................................................................................................... 8 1.2.1 Temperature ..................................................................................................................... 9 1.2.2 Polarisation.................................................................................................................... -
Optimal Reconstruction of Cosmological Density Fields by Benjamin A. Horowitz a Dissertation Submitted in Partial Satisfaction O
Optimal Reconstruction of Cosmological Density Fields By Benjamin A. Horowitz Adissertationsubmittedinpartialsatisfactionofthe requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Uros Seljak, Chair Professor Aaron Parson Professor Martin White Fall 2019 Optimal Reconstruction of Cosmological Density Fields Copyright 2019 by Benjamin A. Horowitz 1 Abstract Optimal Reconstruction of Cosmological Density Fields by Benjamin A. Horowitz Doctor of Philosophy in Physics University of California, Berkeley Professor Uros Seljak, Chair Akeyobjectiveofmoderncosmologyistodeterminethecompositionanddistributionof matter in the universe. While current observations seem to match the standard cosmological model with remarkable precision, there remains tensions between observations as well as mysteries relating to the true nature of dark matter and dark energy. Despite the recent in- creased availability of cosmological data across a wide redshift, these tensions have remained or been further worsened. With the explosion of astronomical data in the coming decade, it has become increasingly critical to extract the maximum possible amount of information available across all available scales. As the available volume for analysis increases, we are no longer sample variance limited and existing summary statistics (as well as related estima- tors) need to be re-examined. Fortunately, parallel with the construction of these surveys there is significant development in the computational techniques used to analyze that data. Algorithmic developments over the past decade and expansion of computational resources allow large cosmological simulations to be run with relative simplicity and parallel theoretical developments motivate increased interest in recovering the underlying large scale structure of the universe beyond the power spectra.