DOCSLIB.ORG

SYNTHETIC OBSERVATIONS USING a ROBUST END-TO-END RADIATIVE TRANSFER MODELING PIPELINE a Dissertation Presented to the Academic F

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

SYNTHETIC OBSERVATIONS USING A ROBUST END-TO-END RADIATIVE TRANSFER MODELING PIPELINE A Dissertation Presented to The Academic Faculty By Kirk Stuart Simeon Barrow In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the School of Physics Georgia Institute of Technology May 2018 Copyright c Kirk Stuart Simeon Barrow 2018 SYNTHETIC OBSERVATIONS USING A ROBUST END-TO-END RADIATIVE TRANSFER MODELING PIPELINE Approved by: Dr. John Wise, Advisor Dr. Tamara Bogdonovic School of Physics School of Physics Georgia Institute of Technology Georgia Institute of Technology Dr. David Ballantyne Dr. Marcus Holzinger School of Physics School of Aerospace Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. Pablo Laguna, Chair Date Approved: March 27, 2018 School of Physics Georgia Institute of Technology Acknowledgments I would first like to thank my thesis advisor Dr. John Wise for his mentorship, his patience, and his insight these long six years from undergrad through to my defense. It has been a harrowing journey and I certainly could not have done it without him. I would also like to thank the Georgia Tech School of Physics and the Center for Relativistic Astrophysics for facilitating an excellent academic program and a continuous stream of invited speakers. I would of course also like to thank the school for taking a chance on me and supporting me financially as a research assistant and a teaching assistant. I would also like to thank Dr. Marcus Holzinger for encouraging me to pursue research in orbital mechanics and Dr. Nathan Strange and the Jet Propulsion Labo- ratory for hosting me for a life-changing summer internship. Finally, I would like to thank my friends and family and especially my partner for always being there to support me and believe in me when the challenges of an academic career felt insurmountable. iii Contents Acknowledgments iii List of Tables vi List of Figures vii Summary xi 1 Observations of the high-redshift Universe1 1.1 Observational Techniques and Constraints............... 2 1.1.1 Cosmological Distances and Flux................ 3 1.1.2 Noise and Optical Effects .................... 5 1.2 Modeling an Unseen Universe...................... 7 1.2.1 The Grand Narrative....................... 7 1.3 Overview of Thesis............................ 10 2 Radiative transfer in cosmological simulations 11 2.1 The Radiative Transfer Equation .................... 11 2.1.1 Extinction............................. 11 2.1.2 Scattering............................. 17 2.1.3 Emission.............................. 19 2.1.4 Point Sources........................... 24 2.1.5 Constructing the Equation.................... 30 2.2 Numerical Solution Methods....................... 32 2.2.1 Adaptive Ray Tracing (Enzo).................. 33 2.2.2 Monte Carlo (Hyperion).................... 34 3 Exploring the spectra of high-redshift galaxies in the Renaissance Simulations 37 3.1 Introduction and Background ...................... 38 3.1.1 EoR Galaxy Observations .................... 38 3.1.2 EoR Galaxy Simulations..................... 39 3.1.3 Synthetic Observations...................... 41 3.2 Research Methods............................. 42 3.2.1 Simulation Techniques...................... 42 3.2.2 Halo Analysis........................... 45 iv 3.2.3 Spectrum Building ........................ 46 3.2.4 Filters, Magnitudes, and Images................. 49 3.3 Results................................... 54 3.3.1 Aggregate Halo Statistics..................... 55 3.3.2 Individual Halos ......................... 68 3.4 Discussion................................. 71 3.4.1 Comparable Works........................ 72 3.4.2 Applications............................ 74 3.4.3 Future Enhancements ...................... 74 3.5 Conclusions................................ 75 4 Emission lines, population III stars, and X-ray binaries 78 4.1 Introduction and Background ...................... 79 4.1.1 Population III stars and X-ray Binaries............. 79 4.1.2 Emission Lines .......................... 80 4.2 Methods.................................. 80 4.2.1 Stellar Spectra .......................... 81 4.2.2 Emission Line Extinction..................... 84 4.2.3 High Mass X-Ray Binaries.................... 90 4.2.4 Spectral Energy Distribution Analysis ............. 93 4.3 Results................................... 93 4.3.1 Stellar Population Merger Scenario............... 95 4.3.2 Population III Galaxy Scenario ................. 102 4.3.3 Emission Lines .......................... 105 4.3.4 Aggregate Spectrographic and Photometric Results . 109 4.4 Discussion................................. 114 4.5 Conclusion................................. 117 5 Observational signatures of massive black hole formation in the early universe 119 5.1 Methods.................................. 120 5.1.1 Simulation............................. 120 5.1.2 Radiative Transfer Post-Processing ............... 122 5.2 Results................................... 124 5.2.1 Comparisons to Literature.................... 137 6 Conclusions and future work 139 6.1 Future Work................................ 140 A Theory of World Structure 146 Bibliography 149 v List of Tables 3.1 Linear regression analysis between flux (z = 15) and stellar mass.... 60 3.2 Linear regression analysis between apparent magnitude (z = 15) and stellar mass................................. 61 3.3 Individual halo properties ........................ 68 4.1 Individual metal-poor halo properties................... 112 vi List of Figures 2.1 Gas specific luminosity versus temperature............... 23 2.2 Hertzsprung-Russell diagram from the Gliese and Jahreiß [1] catalog of nearby stars produced by Richard Powell............... 25 2.3 Specific luminosity of stars by metallicity. Population III specific lumi- nosities for the PopIII.1 and PopIII.2 IMF prescriptions are presented. 26 2.4 Galaxy specific luminosities versus stellar mass fraction for haloes in the \rare peak" of the Renaissance Simulations[2] at z = 15....... 28 3.1 Halo number counts in the Renaissance Simulations rare peak region for star-hosting haloes as a function of halo mass (left) and stellar mass (right).................................... 43 3.2 A sample synthetic spectra placed at z = 15 overlaid with selected HST and JWST filters.............................. 50 3.3 Contour histograms and scatter plots of total bolometric luminosity versus halo mass and stellar mass..................... 52 3.4 Colour-colour plots of star-hosting haloes coloured by their mass-averaged stellar age and stellar masses. ...................... 53 3.5 Colour J200w -J277w versus stellar mass coloured by the mass-weighted stellar age.................................. 54 3.6 The evolution of average colour-colour plot as the spectra are redshifted in the range z = 8 − 15........................... 55 3.7 Emission line measures as a function of stellar mass........... 56 vii 3.8 Contour histograms and scatter plots corresponding to the Hubble f160w and JWST f277w filters. ..................... 61 3.9 Stacked galactic spectra with mean values in blue and 1σ bands in grey in different stellar mass range and gas-poor and gas-rich haloes.... 62 3.10 S ii and N ii BPT diagrams of the emission line ratios coloured by specific star formation rate. ....................... 62 3.11 The UV slope of averaged spectra versus stellar mass.......... 64 3.12 Synthetic imaging and spectrum of Halo A................ 65 3.13 Variations of emergent flux and gas properties of Halo A along different lines of sight. ............................... 66 9 7 3.14 Halo B (Mtot = 1:62 × 10 M , M? = 3:4 × 10 M ) plotted in the same manner as Halo A in Figure 3.12..................... 67 4.1 Top Row: Total extinction profiles for gas and metal emission lines and a gas absorption continuum as a function of wavelength and tempera- ture. Bottom Row: Corresponding emission profiles assuming thermo- dynamic equilibrium............................ 82 4.2 Isothermal cross-sections of extinction profiles.............. 85 4.3 Number of Population III stars, number of X-ray binaries, fraction of X-ray binaries, and fraction of high mass X-ray binaries for a burst of star formation............................... 88 4.4 Multi-color disk (MCD) and power law (PL) components of a SED from a 40 M black hole accreting at the Eddington Limit....... 90 4.5 Plot of total metal-free stellar mass versus total halo mass coloured by metal-free stellar fraction of the total stellar mass............ 92 4.6 Top row: Integral of density-weighted mean density, density-weighted mean temperature, and density-weighted mean metallicity. Bottom row: Integrated total emission, scattering per unit area, and integrated dust emission................................ 94 viii 4.7 Top Row: The spectra of Halo A shown before the application of lines with lines from gas in close proximity to the star and after extinction. Bottom row: The ratio of emission to the nearest wavelength in the intrinsic spectrum and the mean difference between the mean emission wavelength and the mean absorption wavelength for the combination of both gas and dust............................ 96 4.8 A compact Population III stellar cluster plotted in the same manner as Figure 4.6. ............................... 97 4.9 Halo B plotted in the same manner as Figure 4.7............ 98 4.10 Left: Four most common emission lines amongst halos in our simulation with active Population III stars and only metal-enriched stars . Right: Emission
Recommended publications
  • Two Stellar Components in the Halo of the Milky Way

    Two Stellar Components in the Halo of the Milky Way

    1 Two stellar components in the halo of the Milky Way Daniela Carollo1,2,3,5, Timothy C. Beers2,3, Young Sun Lee2,3, Masashi Chiba4, John E. Norris5 , Ronald Wilhelm6, Thirupathi Sivarani2,3, Brian Marsteller2,3, Jeffrey A. Munn7, Coryn A. L. Bailer-Jones8, Paola Re Fiorentin8,9, & Donald G. York10,11 1INAF - Osservatorio Astronomico di Torino, 10025 Pino Torinese, Italy, 2Department of Physics & Astronomy, Center for the Study of Cosmic Evolution, 3Joint Institute for Nuclear Astrophysics, Michigan State University, E. Lansing, MI 48824, USA, 4Astronomical Institute, Tohoku University, Sendai 980-8578, Japan, 5Research School of Astronomy & Astrophysics, The Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Australian Capital Territory 2611, Australia, 6Department of Physics, Texas Tech University, Lubbock, TX 79409, USA, 7US Naval Observatory, P.O. Box 1149, Flagstaff, AZ 86002, USA, 8Max-Planck-Institute für Astronomy, Königstuhl 17, D-69117, Heidelberg, Germany, 9Department of Physics, University of Ljubljana, Jadronska 19, 1000, Ljubljana, Slovenia, 10Department of Astronomy and Astrophysics, Center, 11The Enrico Fermi Institute, University of Chicago, Chicago, IL, 60637, USA The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, which can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for is dichotomy has slowly emerged in recent years from inspection of small samples of halo objects. Here we show that the halo is indeed clearly divisible into two broadly overlapping structural components -- an inner and an outer halo – that exhibit different spatial density profiles, stellar orbits and stellar metallicities (abundances of elements heavier than helium).
  • An Outline of Stellar Astrophysics with Problems and Solutions

    An Outline of Stellar Astrophysics with Problems and Solutions

    An Outline of Stellar Astrophysics with Problems and Solutions Using Maple R and Mathematica R Robert Roseberry 2016 1 Contents 1 Introduction 5 2 Electromagnetic Radiation 7 2.1 Specific intensity, luminosity and flux density ............7 Problem 1: luminous flux (**) . .8 Problem 2: galaxy fluxes (*) . .8 Problem 3: radiative pressure (**) . .9 2.2 Magnitude ...................................9 Problem 4: magnitude (**) . 10 2.3 Colour ..................................... 11 Problem 5: Planck{Stefan-Boltzmann{Wien{colour (***) . 13 Problem 6: Planck graph (**) . 13 Problem 7: radio and visual luminosity and brightness (***) . 14 Problem 8: Sirius (*) . 15 2.4 Emission Mechanisms: Continuum Emission ............. 15 Problem 9: Orion (***) . 17 Problem 10: synchrotron (***) . 18 Problem 11: Crab (**) . 18 2.5 Emission Mechanisms: Line Emission ................. 19 Problem 12: line spectrum (*) . 20 2.6 Interference: Line Broadening, Scattering, and Zeeman splitting 21 Problem 13: natural broadening (**) . 21 Problem 14: Doppler broadening (*) . 22 Problem 15: Thomson Cross Section (**) . 23 Problem 16: Inverse Compton scattering (***) . 24 Problem 17: normal Zeeman splitting (**) . 25 3 Measuring Distance 26 3.1 Parallax .................................... 27 Problem 18: parallax (*) . 27 3.2 Doppler shifting ............................... 27 Problem 19: supernova distance (***) . 28 3.3 Spectroscopic parallax and Main Sequence fitting .......... 28 Problem 20: Main Sequence fitting (**) . 29 3.4 Standard candles ............................... 30 Video: supernova light curve . 30 Problem 21: Cepheid distance (*) . 30 3.5 Tully-Fisher relation ............................ 31 3.6 Lyman-break galaxies and the Hubble flow .............. 33 4 Transparent Gas: Interstellar Gas Clouds and the Atmospheres and Photospheres of Stars 35 2 4.1 Transfer equation and optical depth .................. 36 Problem 22: optical depth (**) . 37 4.2 Plane-parallel atmosphere, Eddington's approximation, and limb darkening ..................................
  • Physics 305, Fall 2008 Problem Set 8 Due Thursday, December 3

    Physics 305, Fall 2008 Problem Set 8 Due Thursday, December 3

    Physics 305, Fall 2008 Problem Set 8 due Thursday, December 3 1. Einstein A and B coefficients (25 pts): This problem is to make sure that you have read and understood Griffiths 9.3.1. Consider a system that consists of atoms with two energy levels E1 and E2 and a thermal gas of photons. There are N1 atoms with energy E1, N2 atoms with energy E2 and the energy density of photons with frequency ! = (E2 − E1)=~ is W (!). In thermal equilbrium at temperature T , W is given by the Planck distribution: ~!3 1 W (!) = 2 3 : π c exp(~!=kBT ) − 1 According to Einstein, this formula can be understood by assuming the following rules for the interaction between the atoms and the photons • Atoms with energy E1 can absorb a photon and make a transition to the excited state with energy E2; the probability per unit time for this transition to take place is proportional to W (!), and therefore given by Pabs = B12W (!) for some constant B12. • Atoms with energy E2 can make a transition to the lower energy state via stimulated emission of a photon. The probability per unit time for this to happen is Pstim = B21W (!) for some constant B21. • Atoms with energy E2 can also fall back into the lower energy state via spontaneous emission. The probability per unit time for spontaneous emission is independent of W (!). Let's call this probability Pspont = A21 : A21, B21, and B12 are known as Einstein coefficients. a. Write a differential equation for the time dependence of the occupation numbers N1 and N2.
  • Inis: Terminology Charts

    Inis: Terminology Charts

    IAEA-INIS-13A(Rev.0) XA0400071 INIS: TERMINOLOGY CHARTS agree INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, AUGUST 1970 INISs TERMINOLOGY CHARTS TABLE OF CONTENTS FOREWORD ... ......... *.* 1 PREFACE 2 INTRODUCTION ... .... *a ... oo 3 LIST OF SUBJECT FIELDS REPRESENTED BY THE CHARTS ........ 5 GENERAL DESCRIPTOR INDEX ................ 9*999.9o.ooo .... 7 FOREWORD This document is one in a series of publications known as the INIS Reference Series. It is to be used in conjunction with the indexing manual 1) and the thesaurus 2) for the preparation of INIS input by national and regional centrea. The thesaurus and terminology charts in their first edition (Rev.0) were produced as the result of an agreement between the International Atomic Energy Agency (IAEA) and the European Atomic Energy Community (Euratom). Except for minor changesq the terminology and the interrela- tionships btween rms are those of the December 1969 edition of the Euratom Thesaurus 3) In all matters of subject indexing and ontrol, the IAEA followed the recommendations of Euratom for these charts. Credit and responsibility for the present version of these charts must go to Euratom. Suggestions for improvement from all interested parties. particularly those that are contributing to or utilizing the INIS magnetic-tape services are welcomed. These should be addressed to: The Thesaurus Speoialist/INIS Section Division of Scientific and Tohnioal Information International Atomic Energy Agency P.O. Box 590 A-1011 Vienna, Austria International Atomic Energy Agency Division of Sientific and Technical Information INIS Section June 1970 1) IAEA-INIS-12 (INIS: Manual for Indexing) 2) IAEA-INIS-13 (INIS: Thesaurus) 3) EURATOM Thesaurusq, Euratom Nuclear Documentation System.
  • Galactic Metal-Poor Halo E NCYCLOPEDIA of a STRONOMY and a STROPHYSICS

    Galactic Metal-Poor Halo E NCYCLOPEDIA of a STRONOMY and a STROPHYSICS

    Galactic Metal-Poor Halo E NCYCLOPEDIA OF A STRONOMY AND A STROPHYSICS Galactic Metal-Poor Halo Most of the gas, stars and clusters in our Milky Way Galaxy are distributed in its rotating, metal-rich, gas-rich and flattened disk and in the more slowly rotating, metal- rich and gas-poor bulge. The Galaxy’s halo is roughly spheroidal in shape, and extends, with decreasing density, out to distances comparable with those of the Magellanic Clouds and the dwarf spheroidal galaxies that have been collected around the Galaxy. Aside from its roughly spheroidal distribution, the most salient general properties of the halo are its low metallicity relative to the bulk of the Galaxy’s stars, its lack of a gaseous counterpart, unlike the Galactic disk, and its great age. The kinematics of the stellar halo is closely coupled to the spheroidal distribution. Solar neighborhood disk stars move at a speed of about 220 km s−1 toward a point in the plane ◦ and 90 from the Galactic center. Stars belonging to the spheroidal halo do not share such ordered motion, and thus appear to have ‘high velocities’ relative to the Sun. Their orbital energies are often comparable with those of the disk stars but they are directed differently, often on orbits that have a smaller component of rotation or angular Figure 1. The distribution of [Fe/H] values for globular clusters. momentum. Following the original description by Baade in 1944, the disk stars are often called POPULATION I while still used to measure R . The recognizability of globular the metal-poor halo stars belong to POPULATION II.
  • Compact Stars

    Compact Stars

    Compact Stars Lecture 12 Summary of the previous lecture I talked about neutron stars, their internel structure, the types of equation of state, and resulting maximum mass (Tolman-Openheimer-Volkoff limit) The neutron star EoS can be constrained if we know mass and/or radius of a star from observations Neutron stars exist in isolation, or are in binaries with MS stars, compact stars, including other NS. These binaries are final product of common evolution of the binary system, or may be a result of capture. Binary NS-NS merger leads to emission of gravitational waves, and also to the short gamma ray burst. The follow up may be observed as a ’kilonova’ due to radioactive decay of high-mass neutron-rich isotopes ejected from merger GRBs and cosmology In 1995, the 'Diamond Jubilee' debate was organized to present the issue of distance scale to GRBs It was a remainder of the famous debate in 1920 between Curtis and Shapley. Curtis argued that the Universe is composed of many galaxies like our own, identified as ``spiral nebulae". Shapley argued that these ``spiral nebulae" were just nearby gas clouds, and that the Universe was composed of only one big Galaxy. Now, Donald Lamb argued that the GRB sources were in the galactic halo while Bodhan Paczyński argued that they were at cosmological distances. B. Paczyński, M. Rees and D. Lamb GRBs and cosmology The GRBs should be easily detectable out to z=20 (Lamb & Reichart 2000). GRB 090429: z=9.4 The IR afterglows of long GRBs can be used as probes of very high z Universe, due to combined effects of cosmological dilation and decrease of intensity with time.
  • Dwarf Galaxies 1 Planck “Merger Tree” Hierarchical Structure Formation

    Dwarf Galaxies 1 Planck “Merger Tree” Hierarchical Structure Formation

    04.04.2019 Grebel: Dwarf Galaxies 1 Planck “Merger Tree” Hierarchical Structure Formation q Larger structures form q through successive Illustris q mergers of smaller simulation q structures. q If baryons are Time q involved: Observable q signatures of past merger q events may be retained. ➙ Dwarf galaxies as building blocks of massive galaxies. Potentially traceable; esp. in galactic halos. Fundamental scenario: q Surviving dwarfs: Fossils of galaxy formation q and evolution. Large structures form through numerous mergers of smaller ones. 04.04.2019 Grebel: Dwarf Galaxies 2 Satellite Disruption and Accretion Satellite disruption: q may lead to tidal q stripping (up to 90% q of the satellite’s original q stellar mass may be lost, q but remnant may survive), or q to complete disruption and q ultimately satellite accretion. Harding q More massive satellites experience Stellar tidal streams r r q higher dynamical friction dV M ρ V from different dwarf ∝ − r 3 galaxy accretion q and sink more rapidly. dt V events lead to ➙ Due to the mass-metallicity relation, expect a highly sub- q more metal-rich stars to end up at smaller radii. structured halo. 04.04.2019 € Grebel: Dwarf Galaxies Johnston 3 De Lucia & Helmi 2008; Cooper et al. 2010 accreted stars (ex situ) in-situ stars Stellar Halo Origins q Stellar halos composed in part of q accreted stars and in part of stars q formed in situ. Rodriguez- q Halos grow from “from inside out”. Gomez et al. 2016 q Wide variety of satellite accretion histories from smooth growth to discrete events.
  • Dark Matter in the Galactic Halo Rotation Curve (I.E

    Dark Matter in the Galactic Halo Rotation Curve (I.E

    Dark matter in the Galactic Halo Rotation curve (i.e. the orbital velocity V of stars and gas as a function of distance to the Galactic Center r) of the disk of the Milky Way is measured: • for the inner Galaxy by looking at the Doppler shift of 21 cm emission from hydrogen • for the outer Galaxy by looking at the velocity of star clusters relative to the Sun. (details of these methods are given in Section 2.3 of Sparke & Gallagher…) Fact that V(r) ~ constant at large radius implies that the Galaxy contains more mass than just the visible stars and gas. Extra mass - the dark matter - normally assumed to reside in an extended, roughly spherical halo around the Galaxy. ASTR 3830: Spring 2004 Possibilities for dark matter include: • molecular hydrogen gas clouds baryonic dark • very low mass stars / brown dwarfs matter - made • stellar remnants: white dwarfs, (originally) from neutron stars, black holes ordinary gas • primordial black holes • elementary particles, probably - non-baryonic dark matter currently unknown The Milky Way halo probably contains some baryonic dark matter - brown dwarfs + stellar remnants accompanying the known population of low mass stars. This uncontroversial component of dark matter is not enough - is the remainder baryonic or non-baryonic? ASTR 3830: Spring 2004 On the largest scales (galaxy clusters and larger), strong evidence that the dark matter has to be non-baryonic: • Abundances of light elements (hydrogen, helium and lithium) formed in the Big Bang depend on how many baryons (protons + neutrons) there were. light element abundances + theory allow a measurement of the number of baryons • observations of dark matter in galaxy clusters suggest there is too much dark matter for it all to be baryons, must be largely non-baryonic.
  • Fundamentals of Radiative Transfer

    Fundamentals of Radiative Transfer

    RADIATIVE PROCESSE S IN ASTROPHYSICS GEORGE B. RYBICKI, ALAN P. LIGHTMAN Copyright 0 2004 WY-VCHVerlag GmbH L Co. KCaA FUNDAMENTALS OF RADIATIVE TRANSFER 1.1 THE ELECTROMAGNETIC SPECTRUM; ELEMENTARY PROPERTIES OF RADIATION Electromagnetic radiation can be decomposed into a spectrum of con- stituent components by a prism, grating, or other devices, as was dis- covered quite early (Newton, 1672, with visible light). The spectrum corresponds to waves of various wavelengths and frequencies, related by Xv=c, where v is the frequency of the wave, h is its wavelength, and c-3.00~10" cm s-I is the free space velocity of light. (For waves not traveling in a vacuum, c is replaced by the appropriate velocity of the wave in the medium.) We can divide the spectrum up into various regions, as is done in Figure 1.1. For convenience we have given the energy E = hv and temperature T= E/k associated with each wavelength. Here h is Planck's constant = 6.625 X erg s, and k is Boltzmann's constant = 1.38 X erg K-I. This chart will prove to be quite useful in converting units or in getting a quick view of the relevant magnitude of quantities in a given portion of the spectrum. The boundaries between different regions are somewhat arbitrary, but conform to accepted usage. 1 2 Fundamentals of Radiatiw Transfer -6 -5 -4 -3 -2 -1 0 1 2 1 I 1 I I I I 1 1 log A (cm) Wavelength I I I I I log Y IHr) Frequency 0 -1 -2 -3 -4 -5 -6 I I I I I I I log Elev) Energy 43 21 0-1 I I 1 I I I log T("K)Temperature Y ray X-ray UV Visible IR Radio Figum 1.1 The electromagnetic spctnun.
  • Acknowledgements Acknowl

    Acknowledgements Acknowl

    1277 Acknowledgements Acknowl. A.1 The Properties of Light by Helen Wächter, Markus W. Sigrist by Richard Haglund The authors thank a number of coworkers for their The author thanks Prof. Emil Wolf for helpful discus- valuable input, notably R. Bartlome, Dr. C. Fischer, sions, and gratefully acknowledges the financial support D. Marinov, Dr. J. Rey, M. Stahel, and Dr. D. Vogler. of a Senior Scientist Award from the Alexander von The financial support by the Swiss National Science Humboldt Foundation and of the Medical Free-Electron Foundation and ETH Zurich for the isotopomer studies Laser program of the Department of Defense (Con- is gratefully acknowledged. tract F49620-01-1-0429) during the preparation of this chapter. by Jürgen Helmcke In writing the chapter on frequency-stabilized lasers, A.4 Nonlinear Optics the author has greatly benefited from fruitful coopera- by Aleksei Zheltikov, Anne L’Huillier, Ferenc Krausz tion and helpful discussions with his colleagues at PTB, We acknowledge the support of the European Com- in particular with Drs. Fritz Riehle, Harald Schnatz, munity’s Human Potential Programme under contract Uwe Sterr, and Harald Telle. Special thanks belong to HPRN-CT-2000-00133 (ATTO) and the Swedish Sci- Dr. Fritz Riehle for his careful and critical reading of the ence Council. manuscript. Part of the work discussed in this chapter was supported by the Deutsche Forschungsgemeinschaft A.5 Optical Materials and Their Properties (DFG) under SFB 407. by Klaus Bonrad The author of Sect. 5.9.2 is grateful to Dr. Thomas C.12 Femtosecond Laser Pulses: Däubler, Dr. Dirk Hertel, and Dr.
  • On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of General Relativity

    On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of General Relativity

    On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of General Relativity Hubert L. Bray ∗ December 22, 2012 Abstract This paper is a sequel to the author’s paper entitled “On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity” which explored a geometrically natural axiomatic definition for dark matter modeled by a scalar field satisfying the Einstein-Klein-Gordon wave equations which, after much calculation, was shown to be consistent with the observed spiral and barred spiral patterns in disk galaxies, as seen in Figures 3, 4, 5, 6. We give an update on where things stand on this “wave dark matter” model of dark matter (aka scalar field dark matter and boson stars), an interesting alternative to the WIMP model of dark matter, and discuss how it has the potential to help explain the long-observed interleaved shell patterns, also known as ripples, in the images of elliptical galaxies. In section 1, we begin with a discussion of dark matter and how the wave dark matter model com- pares with observations related to dark matter, particularly on the galactic scale. In section 2, we show explicitly how wave dark matter shells may occur in the wave dark matter model via approximate solu- tions to the Einstein-Klein-Gordon equations. How much these wave dark matter shells (as in Figure 2) might contribute to visible shells in elliptical galaxies (as in Figure 1) is an important open question. 1 Introduction What is dark matter? No one really knows exactly, in part because dark matter does not interact signif- icantly with light, making it invisible.
  • Subaru Telescope —History, Active/Adaptive Optics, Instruments, and Scientific Achievements—

    Subaru Telescope —History, Active/Adaptive Optics, Instruments, and Scientific Achievements—

    No. 7] Proc. Jpn. Acad., Ser. B 97 (2021) 337 Review Subaru Telescope —History, active/adaptive optics, instruments, and scientific achievements— † By Masanori IYE*1, (Contributed by Masanori IYE, M.J.A.; Edited by Katsuhiko SATO, M.J.A.) Abstract: The Subaru Telescopea) is an 8.2 m optical/infrared telescope constructed during 1991–1999 and has been operational since 2000 on the summit area of Maunakea, Hawaii, by the National Astronomical Observatory of Japan (NAOJ). This paper reviews the history, key engineering issues, and selected scientific achievements of the Subaru Telescope. The active optics for a thin primary mirror was the design backbone of the telescope to deliver a high-imaging performance. Adaptive optics with a laser-facility to generate an artificial guide-star improved the telescope vision to its diffraction limit by cancelling any atmospheric turbulence effect in real time. Various observational instruments, especially the wide-field camera, have enabled unique observational studies. Selected scientific topics include studies on cosmic reionization, weak/strong gravitational lensing, cosmological parameters, primordial black holes, the dynamical/chemical evolution/interactions of galaxies, neutron star mergers, supernovae, exoplanets, proto-planetary disks, and outliers of the solar system. The last described are operational statistics, plans and a note concerning the culture-and-science issues in Hawaii. Keywords: active optics, adaptive optics, telescope, instruments, cosmology, exoplanets largest telescope in Asia and the sixth largest in the 1. Prehistory world. Jun Jugaku first identified a star with excess 1.1. Okayama 188 cm telescope. In 1953, UV as an optical counterpart of the X-ray source Yusuke Hagiwara,1 director of the Tokyo Astronom- Sco X-1.1) Sco X-1 was an unknown X-ray source ical Observatory, the University of Tokyo, empha- found at that time by observations using an X-ray sized in a lecture the importance of building a modern collimator instrument invented by Minoru Oda.2, 2) large telescope.