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Stafford Withington

Bio: Stafford Withington is an academic researcher from University of Cambridge. The author has contributed to research in topics: Detector & Microstrip. The author has an hindex of 26, co-authored 237 publications receiving 3186 citations.


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TL;DR: Cosmic Origins Explorer (Cosmic Explorer) as mentioned in this paper is a full-sky, microwave-band satellite with an angular resolution ranging from 23 arcmin (45 GHz) and 1.3 arcmin(795 GHz).
Abstract: COrE (Cosmic Origins Explorer) is a fourth-generation full-sky, microwave-band satellite recently proposed to ESA within Cosmic Vision 2015-2025. COrE will provide maps of the microwave sky in polarization and temperature in 15 frequency bands, ranging from 45 GHz to 795 GHz, with an angular resolution ranging from 23 arcmin (45 GHz) and 1.3 arcmin (795 GHz) and sensitivities roughly 10 to 30 times better than PLANCK (depending on the frequency channel). The COrE mission will lead to breakthrough science in a wide range of areas, ranging from primordial cosmology to galactic and extragalactic science. COrE is designed to detect the primordial gravitational waves generated during the epoch of cosmic inflation at more than $3\sigma $ for $r=(T/S)>=10^{-3}$. It will also measure the CMB gravitational lensing deflection power spectrum to the cosmic variance limit on all linear scales, allowing us to probe absolute neutrino masses better than laboratory experiments and down to plausible values suggested by the neutrino oscillation data. COrE will also search for primordial non-Gaussianity with significant improvements over Planck in its ability to constrain the shape (and amplitude) of non-Gaussianity. In the areas of galactic and extragalactic science, in its highest frequency channels COrE will provide maps of the galactic polarized dust emission allowing us to map the galactic magnetic field in areas of diffuse emission not otherwise accessible to probe the initial conditions for star formation. COrE will also map the galactic synchrotron emission thirty times better than PLANCK. This White Paper reviews the COrE science program, our simulations on foreground subtraction, and the proposed instrumental configuration.

200 citations

Journal ArticleDOI
Philippe André, Carlo Baccigalupi1, A. J. Banday2, A. J. Banday3  +165 moreInstitutions (53)
TL;DR: Polarized Radiation Imaging and Spectroscopy Mission (PRISM) as mentioned in this paper was proposed to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume.
Abstract: PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The data obtained will allow us to precisely measure the absolute sky brightness and polarization of all the components of the sky emission in the observed frequency range, separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM, which include: (1) the ultimate galaxy cluster survey using the Sunyaev-Zeldovich (SZ) effect, detecting approximately 106 clusters extending to large redshift, including a characterization of the gas temperature of the brightest ones (through the relativistic corrections to the classic SZ template) as well as a peculiar velocity survey using the kinetic SZ effect that comprises our entire Hubble volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where the most of the star formation in the universe took place, the faintest population of which constitute the diffuse CIB (Cosmic Infrared Background); (3) a characterization of the B modes from primordial gravity waves generated during inflation and from gravitational lensing, as well as the ultimate search for primordial non-Gaussianity using CMB polarization, which is less contaminated by foregrounds on small scales than the temperature anisotropies; (4) a search for distortions from a perfect blackbody spectrum, which include some nearly certain signals and others that are more speculative but more informative; and (5) a study of the role of the magnetic field in star formation and its interaction with other components of the interstellar medium of our Galaxy. These are but a few of the highlights presented here along with a description of the proposed instrument.

197 citations

Journal ArticleDOI
Philippe André, Carlo Baccigalupi, A. J. Banday, Domingos Barbosa, Belen Barreiro, James G. Bartlett, Nicola Bartolo, Elia S. Battistelli, Richard A. Battye, George J. Bendo, Alain Benoit, Jean-Philippe Bernard, Marco Bersanelli, Matthieu Béthermin, P. Bielewicz, Anna Bonaldi, F. Bouchet, F. Boulanger, Jan Brand, Martin Bucher, Carlo Burigana, Zhen-Yi Cai, Philippe Camus, F. J. Casas, Viviana Casasola, G. Castex, Anthony Challinor, Jens Chluba, Gayoung Chon, S. Colafrancesco, Barbara Comis, F. Cuttaia, Giuseppe D'Alessandro, Antonio da Silva, Richard J. Davis, Miguel A. de Avillez, Paolo de Bernardis, Marco De Petris, Adriano De Rosa, Gianfranco De Zotti, Jacques Delabrouille, Fran ccois-Xavier Désert, Clive Dickinson, Jose M. Diego, Joanna Dunkley, Torsten A. Enßlin, Josquin Errard, Edith Falgarone, Pedro G. Ferreira, Katia Ferrière, Fabio Finelli, Andrew Fletcher, Pablo Fosalba, Gary A. Fuller, Silvia Galli, Ken Ganga, Juan Garcia-Bellido, A. Ghribi, Martin Giard, Y. Giraud-Héraud, J. González-Nuevo, Keith Grainge, Alessandro Gruppuso, Alex Hall, Jean-Christophe Hamilton, Marijke Haverkorn, Carlos Hernandez-Monte -agudo, D. Herranz, Mark G. Jackson, Andrew H. Jaffe, Rishi Khatri, Martin Kunz, Luca Lamagna, Massimiliano Lattanzi, P. Leahy, Julien Lesgourgues, Michele Liguori, Elisabetta Liuzzo, M. López-Caniego, J. F. Macías-Pérez, Bruno Maffei, Davide Maino, Anna Mangilli, Enrique Martinez-Gonzalez, Carlos Martins, Silvia Masi, Marcella Massardi, Sabino Matarrese, Alessandro Melchiorri, Jean-Baptiste Melin, A. Mennella, A. Mignano, Marc-Antoine Miville-Deschenes, Alessandro Monfardini, Anthony Murphy, Pavel Naselsky, Federico Nati, Paolo Natoli, Mattia Negrello, F. Noviello, Créidhe O'Sullivan, Francesco Paci, Luca Pagano, Rosita Paladino, Nathalie Palanque-Delabrouille, Daniela Paoletti, Hiranya V. Peiris, Francesca Perrotta, F. Piacentini, Michel Piat, Lucio Piccirillo, Giampaolo Pisano, Gianluca Polenta, Agnieszka Pollo, Nicolas Ponthieu, Mathieu Remazeilles, S. Ricciardi, Matthieu Roman, C. Rosset, Jose Alberto Rubino-Martin, Maria Salatino, Alessandro Schillaci, P. Shellard, Joseph Silk, Alexei A. Starobinsky, Radek Stompor, R. A. Sunyaev, Andrea Tartari, Luca Terenzi, L. Toffolatti, M. Tomasi, Neil Trappe, Matthieu Tristram, Tiziana Trombetti, Marco Tucci, Rien Van de Weijgaert, Bartjan van Tent, Licia Verde, P. Vielva, B. D. Wandelt, Robert A. Watson, Stafford Withington 
TL;DR: Polarized Radiation Imaging and Spectroscopy Mission (PRISM) as discussed by the authors was proposed to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume.
Abstract: PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM

133 citations

Journal ArticleDOI
TL;DR: This work has measured the electrodynamic response, quality factor, and resonant frequency of a superconducting aluminium microwave resonator as a function of microwave power and temperature and demonstrates that the effect can only be understood by a nonthermal quasiparticle distribution.
Abstract: In a superconductor, absorption of photons with an energy below the superconducting gap leads to redistribution of quasiparticles over energy and thus induces a strong nonequilibrium quasiparticle energy distribution. We have measured the electrodynamic response, quality factor, and resonant frequency of a superconducting aluminium microwave resonator as a function of microwave power and temperature. Below 200 mK, both the quality factor and resonant frequency decrease with increasing microwave power, consistent with the creation of excess quasiparticles due to microwave absorption. Counterintuitively, above 200 mK, the quality factor and resonant frequency increase with increasing power. We demonstrate that the effect can only be understood by a nonthermal quasiparticle distribution.

127 citations

Posted Content
Philippe André, Carlo Baccigalupi, Domingos Barbosa, J. G. Bartlett, Nicola Bartolo, Elia S. Battistelli, Richard A. Battye, George J. Bendo, Jean-Philippe Bernard, Marco Bersanelli, Matthieu Béthermin, P. Bielewicz, Anna Bonaldi, François R. Bouchet, Francois Boulanger, Jan Brand, M. Bucher, Carlo Burigana, Zhen-Yi Cai, Viviana Casasola, G. Castex, Anthony Challinor, Jens Chluba, Sergio Colafrancesco1, F. Cuttaia, Giuseppe D'Alessandro, Richard J. Davis, Miguel A. de Avillez, Paolo de Bernardis, Marco De Petris, Adriano De Rosa, Gianfranco De Zotti, Jacques Delabrouille, Clive Dickinson, Jose M. Diego, Edith Falgarone, Pedro G. Ferreira, Katia Ferrière2, Fabio Finelli, Andrew Fletcher, Gary A. Fuller, Silvia Galli, K. Ganga, Juan Garcia-Bellido, A. Ghribi, J. González-Nuevo, Keith Grainge, Alessandro Gruppuso, Alex Hall, Carlos Hernández-Monteagudo, Mark G. Jackson, Andrew H. Jaffe, Rishi Khatri, Luca Lamagna, Massimiliano Lattanzi, P. Leahy, Michele Liguori, Elisabetta Liuzzo, M. López-Caniego, J. F. Macías-Pérez, Bruno Maffei, Davide Maino, Silvia Masi, Anna Mangilli, Marcella Massardi, Sabino Matarrese, Alessandro Melchiorri3, Jean-Baptiste Melin, A. Mennella, A. Mignano, Marc-Antoine Miville-Deschenes, Federico Nati, Paolo Natoli, Mattia Negrello, F. Noviello, Francesco Paci, Rosita Paladino, Daniela Paoletti, Francesca Perrotta, F. Piacentini, M. Piat, Lucio Piccirillo, Giampaolo Pisano, Gianluca Polenta, S. Ricciardi, Matthieu Roman, Jose Alberto Rubino-Martin, Maria Salatino, Alessandro Schillaci, P. Shellard, Joseph Silk, Radek Stompor, R. A. Sunyaev, A. Tartari, Luca Terenzi, L. Toffolatti, M. Tomasi, Tiziana Trombetti, Marco Tucci, Bartjan van Tent, Licia Verde, B. D. Wandelt, Stafford Withington 
TL;DR: The polarized radiation imaging and spectroscopy mission (PRISM) as mentioned in this paper was proposed by the European Space Agency (ESA) in response to the Call for White Papers for the definition of the L2 and L3 missions in the ESA Science Programme.
Abstract: PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in response to the Call for White Papers for the definition of the L2 and L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1) an imager with a 3.5m mirror (cooled to 4K for high performance in the far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and (2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS instrument but over three orders of magnitude more sensitive. Highlights of the new science (beyond the obvious target of B-modes from gravity waves generated during inflation) made possible by these two instruments working in tandem include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters extending to large redshift and measuring their peculiar velocities and temperatures (through the kSZ effect and relativistic corrections to the classic y-distortion spectrum, respectively) (2) a detailed investigation into the nature of the cosmic infrared background (CIB) consisting of at present unresolved dusty high-z galaxies, where most of the star formation in the universe took place, (3) searching for distortions from the perfect CMB blackbody spectrum, which will probe a large number of otherwise inaccessible effects (e.g., energy release through decaying dark matter, the primordial power spectrum on very small scales where measurements today are impossible due to erasure from Silk damping and contamination from non-linear cascading of power from larger length scales). These are but a few of the highlights of the new science that will be made possible with PRISM.

121 citations


Cited by
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Journal ArticleDOI
TL;DR: At the highest luminosities (Lir > 1012 ), nearly all objects appear to be advanced mergers powered by a mixture of circumnuclear starburst and active galactic nucleus energy sources, both of which are fueled by an enormous concentration of molecular gas that has been funneled into the merger nucleus as discussed by the authors.
Abstract: ▪ Abstract At luminosities above 1011 , infrared galaxies become the dominant population of extragalactic objects in the local Universe (z ≲ 0.3), being more numerous than optically selected starburst and Seyfert galaxies and quasi-stellar objects at comparable bolometric luminosity. The trigger for the intense infrared emission appears to be the strong interaction/merger of molecular gas-rich spirals, and the bulk of the infrared luminosity for all but the most luminous objects is due to dust heating from an intense starburst within giant molecular clouds. At the highest luminosities (Lir > 1012 ), nearly all objects appear to be advanced mergers powered by a mixture of circumnuclear starburst and active galactic nucleus energy sources, both of which are fueled by an enormous concentration of molecular gas that has been funneled into the merger nucleus. These ultraluminous infrared galaxies may represent an important stage in the formation of quasi-stellar objects and powerful radio galaxies. They may al...

2,911 citations

Journal Article
J. Walkup1
TL;DR: Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.
Abstract: Course Description This is an advanced course in which we explore the field of Statistical Optics. Topics covered include such subjects as the statistical properties of natural (thermal) and laser light, spatial and temporal coherence, effects of partial coherence on optical imaging instruments, effects on imaging due to randomly inhomogeneous media, and a statistical treatment of the detection of light. Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.

1,364 citations

Journal ArticleDOI
16 Jul 1998-Nature
TL;DR: In this article, a deep sub-millimetre-wavelength survey of the Hubble Deep Field was conducted, and the combined radiation of the five most significant detections accounts for 30-50 per cent of the previously unresolved background emission in this area.
Abstract: In the local Universe, most galaxies are dominated by stars, with less than ten per cent of their visible mass in the form of gas. Determining when most of these stars formed is one of the central issues of observational cosmology. Optical and ultraviolet observations of high-redshift galaxies (particularly those in the Hubble Deep Field) have been interpreted as indicating that the peak of star formation occurred between redshifts of 1 and 1.5. But it is known that star formation takes place in dense clouds, and is often hidden at optical wavelengths because of extinction by dust in the clouds. Here we report a deep submillimetre-wavelength survey of the Hubble Deep Field; these wavelengths trace directly the emission from dust that has been warmed by massive star-formation activity. The combined radiation of the five most significant detections accounts for 30–50 per cent of the previously unresolved background emission in this area. Four of these sources appear to be galaxies in the redshift range 2< z < 4, which, assuming these objects have properties comparable to local dust-enshrouded starburst galaxies, implies a star-formation rate during that period about a factor of five higher than that inferred from the optical and ultraviolet observations.

1,322 citations

Journal ArticleDOI
TL;DR: In this article, a Theta vacua of gauge theories is proposed for cosmologists. But the authors do not consider the cosmological perturbation theory of axions in string theory.
Abstract: 1 Introduction 2 Models: the QCD axion; the strong CP problem; PQWW, KSVZ, DFSZ; anomalies, instantons and the potential; couplings; axions in string theory 3 Production and IC's: SSB and non-perturbative physics; the axion field during inflation and PQ SSB; cosmological populations - decay of parent, topological defects, thermal production, vacuum realignment 4 The Cosmological Field: action; background evolution; misalignment for QCD axion and ALPs; cosmological perturbation theory - ic's, early time treatment, axion sound speed and Jeans scale, transfer functions and WDM; the Schrodinger picture; simualting axions; BEC 5 CMB and LSS: Primary anisotropies; matter power; combined constraints; Isocurvature and inflation 6 Galaxy Formation; halo mass function; high-z and the EOR; density profiles; the CDM small-scale crises 7 Accelerated expansion: the cc problem; axion inflation (natural and monodromy) 8 Gravitational interactions with black holes and pulsars 9 Non-gravitational interactions: stellar astrophysics; LSW; vacuum birefringence; axion forces; direct detection with ADMX and CASPEr; Axion decays; dark radiation; astrophysical magnetic fields; cosmological birefringence 10 Conclusions A Theta vacua of gauge theories B EFT for cosmologists C Friedmann equations D Cosmological fluids E Bayes Theorem and priors F Degeneracies and sampling G Sheth-Tormen HMF

1,282 citations

Journal ArticleDOI
Luca Amendola1, Stephen Appleby2, Anastasios Avgoustidis3, David Bacon4, Tessa Baker5, Marco Baldi6, Marco Baldi7, Marco Baldi8, Nicola Bartolo7, Nicola Bartolo9, Alain Blanchard10, Camille Bonvin11, Stefano Borgani7, Stefano Borgani12, Enzo Branchini7, Enzo Branchini13, Clare Burrage3, Stefano Camera, Carmelita Carbone14, Carmelita Carbone7, Luciano Casarini15, Luciano Casarini16, Mark Cropper17, Claudia de Rham18, J. P. Dietrich19, Cinzia Di Porto, Ruth Durrer11, Anne Ealet, Pedro G. Ferreira5, Fabio Finelli7, Juan Garcia-Bellido20, Tommaso Giannantonio19, Luigi Guzzo14, Luigi Guzzo7, Alan Heavens18, Lavinia Heisenberg21, Catherine Heymans22, Henk Hoekstra23, Lukas Hollenstein, Rory Holmes, Zhiqi Hwang24, Knud Jahnke25, Thomas D. Kitching17, Tomi S. Koivisto26, Martin Kunz11, Giuseppe Vacca27, Eric V. Linder28, M. March29, Valerio Marra30, Carlos Martins31, Elisabetta Majerotto11, Dida Markovic32, David J. E. Marsh33, Federico Marulli7, Federico Marulli6, Richard Massey34, Yannick Mellier35, Francesco Montanari36, David F. Mota16, Nelson J. Nunes37, Will J. Percival32, Valeria Pettorino38, Valeria Pettorino39, Cristiano Porciani, Claudia Quercellini, Justin I. Read40, Massimiliano Rinaldi41, Domenico Sapone42, Ignacy Sawicki43, Roberto Scaramella, Constantinos Skordis43, Constantinos Skordis44, Fergus Simpson45, Andy Taylor22, Shaun A. Thomas, Roberto Trotta18, Licia Verde45, Filippo Vernizzi39, Adrian Vollmer, Yun Wang46, Jochen Weller19, T. G. Zlosnik47 
TL;DR: Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015-2025 program as discussed by the authors, which will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shift of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky.
Abstract: Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015–2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky. Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis. This review has been planned and carried out within Euclid’s Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.

1,211 citations