DOCSLIB.ORG

The Dark Energy Survey J

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Dark Energy Survey J Cosmology, Galaxy Formation and Astroparticle Physics on the pathway to the SKA Kl¨ockner, H.-R., Jarvis, M. & Rawlings, S. (eds.) April 10th-12th 2006, Oxford, United Kingdom The Dark Energy Survey J. Weller1, J. Frieman2,3, O. Lahav1 and Z. Ma4 for the DES collaboration 1 Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, U.K. 2 Particle Astrophysics Center, Fermilab National Accelerator Laboratory, Batavia, IL-60510-0500, USA 3 Kavli Institute for Cosmological Physics and Department of Astronomy & Astrophysics, The University of Chicago, Chicago, IL 60637 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia PA 19104 Abstract. The Dark Energy Survey is proposing to constrain dark energy with four complementary probes: galaxy cluster counts, weak lensing, galaxy clustering and Type Ia Supernovae. In order to achieve this a new 3 deg2 CCD camera will be mounted on the Blanco 4-m telescope at the Cerro Tololo Inter-American Observatory (CTIO). The camera will be sensitive up to 24th magnitude in the g,r,i and z bands. The proposed observation will cover 5,000 deg2 of the sky and overlap with the field of the South Pole Telescope (SPT), which will perform a blind survey of galaxy clusters, selected by their Sunyaev-Zel’dovich decrement. The specifications of DES will allow to constrain the equation of state parameter of dark energy to better then a few percent. accuracy. 1. Introduction luminosity distance dL = (1+z)r(z), standard rulers with probes of the angular diameter distance d = (1+z)−1r(z) One of the biggest challenges in modern cosmology is A or probes of the volume dV/(dz dΩ) = r2(z)H(z). to reveal the cause for the accelerated expansion of the Secondly there are probes of the growth factor Universe. There are three possible explanations for the ob- served accelerated expansion: Firstly there is an additional 3 H0 3 H2 D00 + D0 + = 0 a−5Ω D , (2) component in the energy-momentum tensor, namely dark a H 2 H2 m energy, which has a pressure pDE ρDE/3, secondly gravity could be modified on large scales≤ − and thirdly an with D the fluctuation in the matter component and inhomogeneous Universe. The ’simplest’ model to fit the primes denoting derivatives with respect to the scale fac- data is a Universe with a Cosmological Constant, although tor a. Note that usually in modified gravity scenarios the this comes then with the problem of the need to explain term on the right is modified. the origin of the observed value with fundamental physics. The majority of the material presented in the follow- The first question surveys need to answer is if the ing sections is discussed in detail in the report (The Dark dark energy is observationally distinguishable from a Energy Survey Collaboration, 2005) submitted to the Cosmological Constant? In order to decide this one has to Dark Energy Task Force (DETF)(Albrecht et al., 2006). measure the equation of state w = pDE/ρDE possibly at The international DES collaboration includes universities different redshifts. A Cosmological Constant corresponds from the US, the UK, Spain, and Brazil. The DES:UK con- to w = 1. A further question is if it is possible to dis- sortium (UCL, Portsmouth, Cambridge, Edinburgh and tinguish− modifications of gravity from a dark energy com- Sussex) has now received support from PPARC towards ponent and finally in case w = 1 if it is evolving with the wide field optical corrector for DES. 6 − redshift? In the following we choose w = w0 + wa(1 a) as the parameterization for the equation of state (Linder,− 2. The Instrument and Survey 2003). There are many means to probe cosmology in the The main challenge for the DES collaboration is to build Universe, but the majority of them fall in two categories. a new camera and corrector for the 4m Blanco telescope. First there are geometrical probes, which mainly probe The major components are a 519 megapixel CCD camera the different weights of the comoving distance a wide field optical corrector with 2.2 deg field of view, a dz four band filter system with g,r,i and z filters, guide and r(z)= (1) focus sensors mounted on the focal plane, low-noise CCD H(z) Z readout, a cryogenic cooling system to maintain the focal where H(z) is the Hubble parameter given in plane at 180 K, as well as a data acquisition and instru- standard gravity at late times by H2(z) = ment control system to connect to the Blanco observatory 2 3 3(1+w) H0 Ωm(1 + z) +ΩDE(1 + z) , in a flat Universe infrastructure. The camera focal plane will consist of sixty- with a constant equation of state factor w. Geometrical two 2k x 4k CCDs (0.27”/pixel) arranged in a hexagon probes are then standard candles, i.e. probes of the covering an imaging area of 3 square degrees. Smaller for- J. Weller, J. Frieman,, O. Lahav and Z. Ma for the DES collaboration: The Dark Energy Survey bolometer array in its focal plane (Ruhl et al., 2004). It consists of a 1 arcminute beam and operates in 3-4 fre- quency bands at (90), 150, 250 and 270 GHz. This will allow blind observations of galaxy clusters selected by the Sunyaev-Zel’dovich decrement. Given the complemen- tary redshift information from DES it is then possible to count clusters of galaxies in bins of redshift. This can be compared to theoretical predictions of structure formation with dV ∞ dn ∆N = ∆Ω dz dM , (3) dzdΩ dM Zzbin ZMlim(z) where ∆Ω is the survey area, dn/dM the mass func- Fig. 1. Model of the Dark Energy Camera (DECam). tion and Mlim(z) the selection function depending on the survey parameters, cosmological parameters and the gas mat CCDs for guiding and focusing will be located at the physics in the cluster. The sensitivity of the SPT is about edges of the focal plane. 1.5 mJy for a 4-σ detection threshold of a cluster. This cor- 14 responds to a limiting mass of 1.7 10 M , also this num- To carry out the Dark Energy Survey, we have re- × quested 525 nights of observing on the Blanco tele- ber is varying slightly with redshift. Typically the mass scope over 5 years, concentrated between September and function is established with N-body simulations (Jenkins February, beginning in Sept. 2009. With that time, we et al., 2001) and fit to analytical expression like for ex- expect to reach photometric limits of g=24.6, r=24.1, ample the Sheth-Tormen mass function (Sheth & Tormen, i=24.3, and z=23.9 over 5000 square degrees of sky. These 2002). The most commonly used mass function by Jenkins are 10σ limits in 1.5” apertures assuming 0.9” seeing and et al. (2001) is given by are appropriate for faint galaxies; the corresponding 5σ m dn (z,M) = 0.316 ρ (t0) dσM 1 limit for point sources is 1.5 mags fainter. These limits dM − M dM σM (4) exp 0.67 log [D(z)σ ] 3.82 , and the adopted median delivered seeing are derived from × −| − M | detailed survey simulations that incorporate weather and with σM the rms fluctuation on mass scale M, D (z) the seeing data at CTIO over a 30-year baseline. growth factor of linear perturbations and ρm(t0) the mat- The survey strategy is designed to optimize the pho- ter density today. In order to predict the number of clus- tometric calibration by tiling each region of the survey ter in redshift bins we require to convert the Sunyaev- with at least four overlapping pointings in each band. This Zel’dovich flux limit of the survey to a mass limit. For provides uniformity of coverage and control of systematic this we assume a relation between mass and tempera- photometric errors via relative photometry on scales up ture, which allows deviations from hydrostatic equilibrium to the survey size. This strategy will enable us to de- (Verde et al., 2002; Battye & Weller, 2003) with a tem- termine photometric redshifts (photo-z’s) of galaxies to perature relation of an accuracy of σ(z) 0.07 , with some dependence on ∼ 1/3 2/3 1− 1/ξ redshift and galaxy type, cluster photometric redshifts to Te = T∗∆c H(z) (1 + z) Mvir , (5) σ(z) 0.02 or better out to z 1.3, and shapes for approximately∼ 200 million galaxies;∼ these measurements where T∗ is the normalization, ∆c the spherical over- will be sufficient to meet the survey science requirements. density of the cluster at virialization, the redshift de- 4000 deg2 of the survey region will overlap the South Pole pendence and ξ the power-law for the variation with Telescope (Ruhl et al., 2004) Sunyaev-Zel’dovich survey mass. Assuming virialization would result in = 1 and region; the remainder will provide coverage of spectro- ξ = 1.5. We use T∗ = 1.6 as motivated by hydro sim- scopic redshift training sets, including the SDSS southern ulations (Battye & Weller, 2003). Also a deviation from virialization might be expected it turns out that clusters equatorial stripe, and more complete coverage near the 14 South Galactic pole. In order to extract cosmology from with masses larger than 10 M follow relatively closely the dark energy survey a certain accuracy in the photo- the scaling relation from virialization (Motl et al., 2005; metric redshifts is required. This is achieved by measuring Nagai, 2006). We include the parameters T∗, ξ and as free the relative flux in the g,r,i and z filters and observe the parameters in the cluster count analysis, which leads to a 4000A˚ break.
Load more

Recommended publications
  • Report from the Dark Energy Task Force (DETF)
    Fermi National Accelerator Laboratory Fermilab Particle Astrophysics Center P.O.Box 500 - MS209 Batavia, Il l i noi s • 60510 June 6, 2006 Dr. Garth Illingworth Chair, Astronomy and Astrophysics Advisory Committee Dr. Mel Shochet Chair, High Energy Physics Advisory Panel Dear Garth, Dear Mel, I am pleased to transmit to you the report of the Dark Energy Task Force. The report is a comprehensive study of the dark energy issue, perhaps the most compelling of all outstanding problems in physical science. In the Report, we outline the crucial need for a vigorous program to explore dark energy as fully as possible since it challenges our understanding of fundamental physical laws and the nature of the cosmos. We recommend that program elements include 1. Prompt critical evaluation of the benefits, costs, and risks of proposed long-term projects. 2. Commitment to a program combining observational techniques from one or more of these projects that will lead to a dramatic improvement in our understanding of dark energy. (A quantitative measure for that improvement is presented in the report.) 3. Immediately expanded support for long-term projects judged to be the most promising components of the long-term program. 4. Expanded support for ancillary measurements required for the long-term program and for projects that will improve our understanding and reduction of the dominant systematic measurement errors. 5. An immediate start for nearer term projects designed to advance our knowledge of dark energy and to develop the observational and analytical techniques that will be needed for the long-term program. Sincerely yours, on behalf of the Dark Energy Task Force, Edward Kolb Director, Particle Astrophysics Center Fermi National Accelerator Laboratory Professor of Astronomy and Astrophysics The University of Chicago REPORT OF THE DARK ENERGY TASK FORCE Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude.
    [Show full text]
  • Fine-Tuning, Complexity, and Life in the Multiverse*
    Fine-Tuning, Complexity, and Life in the Multiverse* Mario Livio Dept. of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA E-mail: [email protected] and Martin J. Rees Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK E-mail: [email protected] Abstract The physical processes that determine the properties of our everyday world, and of the wider cosmos, are determined by some key numbers: the ‘constants’ of micro-physics and the parameters that describe the expanding universe in which we have emerged. We identify various steps in the emergence of stars, planets and life that are dependent on these fundamental numbers, and explore how these steps might have been changed — or completely prevented — if the numbers were different. We then outline some cosmological models where physical reality is vastly more extensive than the ‘universe’ that astronomers observe (perhaps even involving many ‘big bangs’) — which could perhaps encompass domains governed by different physics. Although the concept of a multiverse is still speculative, we argue that attempts to determine whether it exists constitute a genuinely scientific endeavor. If we indeed inhabit a multiverse, then we may have to accept that there can be no explanation other than anthropic reasoning for some features our world. _______________________ *Chapter for the book Consolidation of Fine Tuning 1 Introduction At their fundamental level, phenomena in our universe can be described by certain laws—the so-called “laws of nature” — and by the values of some three dozen parameters (e.g., [1]). Those parameters specify such physical quantities as the coupling constants of the weak and strong interactions in the Standard Model of particle physics, and the dark energy density, the baryon mass per photon, and the spatial curvature in cosmology.
    [Show full text]
  • Cosmology Slides
    Inhomogeneous cosmologies George Ellis, University of Cape Town 27th Texas Symposium on Relativistic Astrophyiscs Dallas, Texas Thursday 12th December 9h00-9h45 • The universe is inhomogeneous on all scales except the largest • This conclusion has often been resisted by theorists who have said it could not be so (e.g. walls and large scale motions) • Most of the universe is almost empty space, punctuated by very small very high density objects (e.g. solar system) • Very non-linear: / = 1030 in this room. Models in cosmology • Static: Einstein (1917), de Sitter (1917) • Spatially homogeneous and isotropic, evolving: - Friedmann (1922), Lemaitre (1927), Robertson-Walker, Tolman, Guth • Spatially homogeneous anisotropic (Bianchi/ Kantowski-Sachs) models: - Gödel, Schücking, Thorne, Misner, Collins and Hawking,Wainwright, … • Perturbed FLRW: Lifschitz, Hawking, Sachs and Wolfe, Peebles, Bardeen, Ellis and Bruni: structure formation (linear), CMB anisotropies, lensing Spherically symmetric inhomogeneous: • LTB: Lemaître, Tolman, Bondi, Silk, Krasinski, Celerier , Bolejko,…, • Szekeres (no symmetries): Sussman, Hellaby, Ishak, … • Swiss cheese: Einstein and Strauss, Schücking, Kantowski, Dyer,… • Lindquist and Wheeler: Perreira, Clifton, … • Black holes: Schwarzschild, Kerr The key observational point is that we can only observe on the past light cone (Hoyle, Schücking, Sachs) See the diagrams of our past light cone by Mark Whittle (Virginia) 5 Expand the spatial distances to see the causal structure: light cones at ±45o. Observable Geo Data Start of universe Particle Horizon (Rindler) Spacelike singularity (Penrose). 6 The cosmological principle The CP is the foundational assumption that the Universe obeys a cosmological law: It is necessarily spatially homogeneous and isotropic (Milne 1935, Bondi 1960) Thus a priori: geometry is Robertson-Walker Weaker form: the Copernican Principle: We do not live in a special place (Weinberg 1973).
    [Show full text]
  • Arxiv:1707.01004V1 [Astro-Ph.CO] 4 Jul 2017
    July 5, 2017 0:15 WSPC/INSTRUCTION FILE coc2ijmpe International Journal of Modern Physics E c World Scientific Publishing Company Primordial Nucleosynthesis Alain Coc Centre de Sciences Nucl´eaires et de Sciences de la Mati`ere (CSNSM), CNRS/IN2P3, Univ. Paris-Sud, Universit´eParis–Saclay, Bˆatiment 104, F–91405 Orsay Campus, France [email protected] Elisabeth Vangioni Institut d’Astrophysique de Paris, UMR-7095 du CNRS, Universit´ePierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France), Sorbonne Universit´es, Institut Lagrange de Paris, 98 bis bd Arago, 75014 Paris (France) [email protected] Received July 5, 2017 Revised Day Month Year Primordial nucleosynthesis, or big bang nucleosynthesis (BBN), is one of the three evi- dences for the big bang model, together with the expansion of the universe and the Cos- mic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4He, D, 3He and 7Li deduced from observations, and calculated in primordial nucleosynthesis. However, there remains a yet–unexplained discrepancy of a factor ≈3, between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics experiments, nor by new observations. The precision in deuterium observations in cosmological clouds has recently improved dramatically, so that nuclear cross sections involved in deuterium BBN need to be known with similar precision. We will shortly discuss nuclear aspects re- lated to BBN of Li and D, BBN with non-standard neutron sources, and finally, improved sensitivity studies using Monte Carlo that can be used in other sites of nucleosynthesis.
    [Show full text]
  • Dark Energy and CMB
    Dark Energy and CMB Conveners: S. Dodelson and K. Honscheid Topical Conveners: K. Abazajian, J. Carlstrom, D. Huterer, B. Jain, A. Kim, D. Kirkby, A. Lee, N. Padmanabhan, J. Rhodes, D. Weinberg Abstract The American Physical Society's Division of Particles and Fields initiated a long-term planning exercise over 2012-13, with the goal of developing the community's long term aspirations. The sub-group \Dark Energy and CMB" prepared a series of papers explaining and highlighting the physics that will be studied with large galaxy surveys and cosmic microwave background experiments. This paper summarizes the findings of the other papers, all of which have been submitted jointly to the arXiv. arXiv:1309.5386v2 [astro-ph.CO] 24 Sep 2013 2 1 Cosmology and New Physics Maps of the Universe when it was 400,000 years old from observations of the cosmic microwave background and over the last ten billion years from galaxy surveys point to a compelling cosmological model. This model requires a very early epoch of accelerated expansion, inflation, during which the seeds of structure were planted via quantum mechanical fluctuations. These seeds began to grow via gravitational instability during the epoch in which dark matter dominated the energy density of the universe, transforming small perturbations laid down during inflation into nonlinear structures such as million light-year sized clusters, galaxies, stars, planets, and people. Over the past few billion years, we have entered a new phase, during which the expansion of the Universe is accelerating presumably driven by yet another substance, dark energy. Cosmologists have historically turned to fundamental physics to understand the early Universe, successfully explaining phenomena as diverse as the formation of the light elements, the process of electron-positron annihilation, and the production of cosmic neutrinos.
    [Show full text]
  • Structure Formation in a CDM Universe
    Structure formation in a CDM Universe Thomas Quinn, University of Washington Greg Stinson, Charlotte Christensen, Alyson Brooks Ferah Munshi Fabio Governato, Andrew Pontzen, Chris Brook, James Wadsley Microwave Background Fluctuations Image courtesy NASA/WMAP Large Scale Clustering A well constrained cosmology ` Contents of the Universe Can it make one of these? Structure formation issues ● The substructure problem ● The angular momentum problem ● The cusp problem Light vs CDM structure Stars Gas Dark Matter The CDM Substructure Problem Moore et al 1998 Substructure down to 100 pc Stadel et al, 2009 Consequences for direct detection Afshordi etal 2010 Warm Dark Matter cold warm hot Constant Core Mass Strigari et al 2008 Light vs Mass Number density log(halo or galaxy mass) Simulations of Galaxy formation Guo e tal, 2010 Origin of Galaxy Spins ● Torques on the collapsing galaxy (Peebles, 1969; Ryden, 1988) λ ≡ L E1/2/GM5/2 ≈ 0.09 for galaxies Distribution of Halo Spins f(λ) Λ = LE1/2/GM5/2 Gardner, 2001 Angular momentum Problem Too few low-J baryons Van den Bosch 01 Bullock 01 Core/Cusps in Dwarfs Moore 1994 Warm DM doesn't help Moore et al 1999 Dwarf simulated to z=0 Stellar mass = 5e8 M sun` M = -16.8 i g - r = 0.53 V = 55 km/s rot R = 1 kpc d M /M = 2.5 HI * f = .3 f cosmic b b i band image Dwarf Light Profile Rotation Curve Resolution effects Low resolution: bad Low resolution star formation: worse Inner Profile Slopes vs Mass Governato, Zolotov etal 2012 Constant Core Masses Angular Momentum Outflows preferential remove low J baryons Simulation Results: Resolution and H2 Munshi, in prep.
    [Show full text]
  • High Redshift Quasar Hunting with the Dark Energy Survey
    High Redshift Quasar Hunting with the Dark Energy Survey Quasars in the Epoch of Reionisation Sophie Reed Supervisors: Richard McMahon, Manda Banerji 1 Why? ★ Theories of black hole formation and evolution z = 6 - 15 z = 2 WORDS Epoch of peak of galaxy Reionization and quasar ★ Metal abundances in the early universe activity ★ Gas distribution and reionisationv z = 20 - 30 z = 6 - 8 Start of z = 1100 first stars Reionization matter-radiation “Population III” decoupling (CMB) 2 Quasar Spectrum at z ~ 6 Spectrum of a z = 5.86 quasar from Venemans et al 2007 Continuum break across rest frame Lyman-alpha (λrest = 121.6nm) gives distinctive colours 3 Quasar Spectrum at z ~ 6 480 nm 640 nm 780 nm 920 nm 990 nm 1252 nm 2147 nm 4 The Dark Energy Survey (DES) First Light September 2012 Very large area when completed: ~5000 deg2, currently have ~2000 deg2 Deep imaging: 10 σ limits for i and z are AB = 23.4 and AB = 23.2 Sophisticated camera, DECam Credit: DES Collaboration 5 DECam Mosaic of 62 2k by 4k CCDs (0.27” pixels) Multi waveband imaging: Visible (400 nm) to Near IR (1050 nm), g, r, i, z and Y bands covered Much more sensitive to red light than SDSS Credit: DES Collaboration 6 DES - SDSS Comparison SDSS was most sensitive to bluer light in the r band DES is most sensitive to redder light in the z band u g r i z Y 7 The VISTA Hemisphere Survey (VHS) Will cover 10,000 deg2 in the infrared when completed VHS-DES (J, H and K) overlaps DES and is deeper VHS-ATLAS (Y, J, H and K) is a shallower survey 8 Currently Known Objects Lots of quasars known
    [Show full text]
  • The High Redshift Universe: Galaxies and the Intergalactic Medium
    The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi M¨unchen2016 The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi Dissertation an der Fakult¨atf¨urPhysik der Ludwig{Maximilians{Universit¨at M¨unchen vorgelegt von Koki Kakiichi aus Komono, Mie, Japan M¨unchen, den 15 Juni 2016 Erstgutachter: Prof. Dr. Simon White Zweitgutachter: Prof. Dr. Jochen Weller Tag der m¨undlichen Pr¨ufung:Juli 2016 Contents Summary xiii 1 Extragalactic Astrophysics and Cosmology 1 1.1 Prologue . 1 1.2 Briefly Story about Reionization . 3 1.3 Foundation of Observational Cosmology . 3 1.4 Hierarchical Structure Formation . 5 1.5 Cosmological probes . 8 1.5.1 H0 measurement and the extragalactic distance scale . 8 1.5.2 Cosmic Microwave Background (CMB) . 10 1.5.3 Large-Scale Structure: galaxy surveys and Lyα forests . 11 1.6 Astrophysics of Galaxies and the IGM . 13 1.6.1 Physical processes in galaxies . 14 1.6.2 Physical processes in the IGM . 17 1.6.3 Radiation Hydrodynamics of Galaxies and the IGM . 20 1.7 Bridging theory and observations . 23 1.8 Observations of the High-Redshift Universe . 23 1.8.1 General demographics of galaxies . 23 1.8.2 Lyman-break galaxies, Lyα emitters, Lyα emitting galaxies . 26 1.8.3 Luminosity functions of LBGs and LAEs . 26 1.8.4 Lyα emission and absorption in LBGs: the physical state of high-z star forming galaxies . 27 1.8.5 Clustering properties of LBGs and LAEs: host dark matter haloes and galaxy environment . 30 1.8.6 Circum-/intergalactic gas environment of LBGs and LAEs .
    [Show full text]
  • Week 5: More on Structure Formation
    Week 5: More on Structure Formation Cosmology, Ay127, Spring 2008 April 23, 2008 1 Mass function (Press-Schechter theory) In CDM models, the power spectrum determines everything about structure in the Universe. In particular, it leads to what people refer to as “bottom-up” and/or “hierarchical clustering.” To begin, note that the power spectrum P (k), which decreases at large k (small wavelength) is psy- chologically inferior to the scaled power spectrum ∆2(k) = (1/2π2)k3P (k). This latter quantity is monotonically increasing with k, or with smaller wavelength, and thus represents what is going on physically a bit more intuitively. Equivalently, the variance σ2(M) of the mass distribution on scales of mean mass M is a monotonically decreasing function of M; the variance in the mass distribution is largest at the smallest scales and smallest at the largest scales. Either way, the density-perturbation amplitude is larger at smaller scales. It is therefore smaller structures that go nonlinear and undergo gravitational collapse earliest in the Universe. With time, larger and larger structures undergo gravitational collapse. Thus, the first objects to undergo gravitational collapse after recombination are probably globular-cluster–sized halos (although the halos won’t produce stars. As we will see in Week 8, the first dark-matter halos to undergo gravitational collapse and produce stars are probably 106 M halos at redshifts z 20. A typical L galaxy probably forms ∼ ⊙ ∼ ∗ at redshifts z 1, and at the current epoch, it is galaxy groups or poor clusters that are the largest ∼ mass scales currently undergoing gravitational collapse.
    [Show full text]
  • Cosmology from Cosmic Shear and Robustness to Data Calibration
    DES-2019-0479 FERMILAB-PUB-21-250-AE Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Data Calibration A. Amon,1, ∗ D. Gruen,2, 1, 3 M. A. Troxel,4 N. MacCrann,5 S. Dodelson,6 A. Choi,7 C. Doux,8 L. F. Secco,8, 9 S. Samuroff,6 E. Krause,10 J. Cordero,11 J. Myles,2, 1, 3 J. DeRose,12 R. H. Wechsler,1, 2, 3 M. Gatti,8 A. Navarro-Alsina,13, 14 G. M. Bernstein,8 B. Jain,8 J. Blazek,7, 15 A. Alarcon,16 A. Ferté,17 P. Lemos,18, 19 M. Raveri,8 A. Campos,6 J. Prat,20 C. Sánchez,8 M. Jarvis,8 O. Alves,21, 22, 14 F. Andrade-Oliveira,22, 14 E. Baxter,23 K. Bechtol,24 M. R. Becker,16 S. L. Bridle,11 H. Camacho,22, 14 A. Carnero Rosell,25, 14, 26 M. Carrasco Kind,27, 28 R. Cawthon,24 C. Chang,20, 9 R. Chen,4 P. Chintalapati,29 M. Crocce,30, 31 C. Davis,1 H. T. Diehl,29 A. Drlica-Wagner,20, 29, 9 K. Eckert,8 T. F. Eifler,10, 17 J. Elvin-Poole,7, 32 S. Everett,33 X. Fang,10 P. Fosalba,30, 31 O. Friedrich,34 E. Gaztanaga,30, 31 G. Giannini,35 R. A. Gruendl,27, 28 I. Harrison,36, 11 W. G. Hartley,37 K. Herner,29 H. Huang,38 E. M. Huff,17 D. Huterer,21 N. Kuropatkin,29 P. Leget,1 A. R. Liddle,39, 40, 41 J.
    [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]
  • Cosmic Visions Dark Energy: Science
    Cosmic Visions Dark Energy: Science Scott Dodelson, Katrin Heitmann, Chris Hirata, Klaus Honscheid, Aaron Roodman, UroˇsSeljak, Anˇze Slosar, Mark Trodden Executive Summary Cosmic surveys provide crucial information about high energy physics including strong evidence for dark energy, dark matter, and inflation. Ongoing and upcoming surveys will start to identify the underlying physics of these new phenomena, including tight constraints on the equation of state of dark energy, the viability of modified gravity, the existence of extra light species, the masses of the neutrinos, and the potential of the field that drove inflation. Even after the Stage IV experiments, DESI and LSST, complete their surveys, there will still be much information left in the sky. This additional information will enable us to understand the physics underlying the dark universe at an even deeper level and, in case Stage IV surveys find hints for physics beyond the current Standard Model of Cosmology, to revolutionize our current view of the universe. There are many ideas for how best to supplement and aid DESI and LSST in order to access some of this remaining information and how surveys beyond Stage IV can fully exploit this regime. These ideas flow to potential projects that could start construction in the 2020's. arXiv:1604.07626v1 [astro-ph.CO] 26 Apr 2016 2 1 Overview This document begins with a description of the scientific goals of the cosmic surveys program in x2 and then x3 presents the evidence that, even after the surveys currently planned for the 2020's, much of the relevant information in the sky will remain to be mined.
    [Show full text]