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UC Irvine UC Irvine Previously Published Works
UC Irvine UC Irvine Previously Published Works Title Astrophysics in 2006 Permalink https://escholarship.org/uc/item/5760h9v8 Journal Space Science Reviews, 132(1) ISSN 0038-6308 Authors Trimble, V Aschwanden, MJ Hansen, CJ Publication Date 2007-09-01 DOI 10.1007/s11214-007-9224-0 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Space Sci Rev (2007) 132: 1–182 DOI 10.1007/s11214-007-9224-0 Astrophysics in 2006 Virginia Trimble · Markus J. Aschwanden · Carl J. Hansen Received: 11 May 2007 / Accepted: 24 May 2007 / Published online: 23 October 2007 © Springer Science+Business Media B.V. 2007 Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords Cosmology: general · Galaxies: general · ISM: general · Stars: general · Sun: general · Planets and satellites: general · Astrobiology · Star clusters · Binary stars · Clusters of galaxies · Gamma-ray bursts · Milky Way · Earth · Active galaxies · Supernovae 1 Introduction Astrophysics in 2006 modifies a long tradition by moving to a new journal, which you hold in your (real or virtual) hands. The fifteen previous articles in the series are referenced oc- casionally as Ap91 to Ap05 below and appeared in volumes 104–118 of Publications of V. -
Hubble Law: Measure and Interpretation
Special Issue on the foundations of astrophysics and cosmology manuscript No. (will be inserted by the editor) Hubble law : measure and interpretation Paturel Georges · Teerikorpi Pekka · Baryshev Yurij Received: date / Accepted: date Abstract We have had the chance to live through a fascinating revolution in measuring the fundamental empirical cosmological Hubble law. The key progress is analysed : 1) improvement of observational means (ground-based radio and optical observations, space missions) ; 2) understanding of the bi- ases that affect both distant and local determinations of the Hubble constant; 3) new theoretical and observational results. These circumstances encourage us to take a critical look at some facts and ideas related to the cosmological red-shift. This is important because we are probably on the eve of a new under- standing of our Universe, heralded by the need to interpret some cosmological key observations in terms of unknown processes and substances. 1 Introduction This paper is a short review concerning the study of the Hubble law. The purpose is to give an overview of the evolution of cosmology with a presentation as simple as possible. In the present section, we give a brief description of the first steps in both conceptual and technical improvements that has led us to the present situation. In section 2, we explain the biases that plagued for decades the G. Paturel Retired from Universite Claude-Bernard, Observatoire de Lyon, 69230 Saint-Genis Laval, France Tel.: +334 78560474 E-mail: [email protected] P. Teerikorpi Tuorla Observatory, Department of Physics and Astronomy, University of Turku, 21500 Pi- ikki¨o, Finland E-mail: pekkatee@utu.fi arXiv:1801.00128v1 [astro-ph.CO] 30 Dec 2017 Y. -
Influence of a Generalized Eddington Bias on Galaxy Counts
A&A 424, 73–78 (2004) Astronomy DOI: 10.1051/0004-6361:20040567 & c ESO 2004 Astrophysics Influence of a generalized Eddington bias on galaxy counts P. Teerikorpi Tuorla Observatory, University of Turku, 21500 Piikkiö, Finland e-mail: [email protected] Received 31 March 2004 / Accepted 11 May 2004 Abstract. We study the influence of the Eddington bias on measured distributions, in particular counts of galaxies when the accuracy of magnitude measurements is variable, e.g. when it changes towards fainter objects. Numerical experiments using different error laws illustrate the effect on the measured slope, helping one to decide if the variable Eddington bias is important, when the simple analytic correction is no longer valid. Common views on the origin and appearance of the Eddington bias are clarified and its relation to the classical Malmquist bias is briefly discussed. We illustrate the “Eddington shift” approach with the counts of bright galaxies in the LEDA database. Key words. galaxies: statistics 1. Introduction Eddington derived the following general relation between the two distributions: Here we study the Eddington bias in a generalized form, keep- ing in mind applications for galaxy counts if the magnitude 1 1 1 2 T(x)= E(x) − σ2d2E(x)/dx2 + σ2 d4E(x)/dx4 − ... (1) accuracy is variable. We assess how much these effects may 2 2 2 influence the counts. For example, to be more immune to lo- cal structures, the counts of bright galaxies should be all-sky, Such an inverse problem, inferring the true distribution from but these are currently based on data with variable accuracy. -
On the Light Echo in V838 Mon
A&A 414, 223–233 (2004) Astronomy DOI: 10.1051/0004-6361:20034015 & c ESO 2004 Astrophysics On the light echo in V838 Mon R. Tylenda N. Copernicus Astronomical Center, Department for Astrophysics, Rabia´nska 8, 87–100 Toru´n, Poland Received 26 June 2003 / Accepted 30 September 2003 Abstract. We present a theoretical outline of the light echo phenomenon and results of simple numerical simulations and we study the available images of the light echo in V838 Mon obtained with HST. An investigation of the observed expansion of the light echo leads us to conclude that the distance to V838 Mon is ∼>5 kpc. From an analysis of the inner bright echo rim we estimate the distance to be 8.0 ± 2.0 kpc. We also investigate the structure of the dust distribution in the vicinity of the object. We find no obvious signs of spherical symmetry in the resultant distribution. Near the central object there is a strongly asymmetric dust-free region which we interpret as produced by a fast wind from the V838 Mon system. The asymmetry would imply that V838 Mon is moving relative to the dusty medium. From these results we conclude that the dust illuminated by the light echo is of interstellar origin rather than produced by mass loss from V838 Mon in the past. Key words. stars: individual: V838 Mon – stars: distances – stars: circumstellar matter – ISM: reflection nebulae 1. Introduction Supernova light echoes can also be used to measure distances to galaxies (Sparks 1994). V838 Mon was discovered in eruption in the beginning of Munari et al. -
Hubble Space Telescope Observations of the Light Echoes Around V838 Monocerotis
Asymmetric Planetary Nebulae III ASP Conference Series, Vol. XXX, 2004 M. Meixner, J. Kastner, B. Balick and N. Soker eds. Hubble Space Telescope Observations of the Light Echoes around V838 Monocerotis Howard E. Bond1, Arne Henden2, Zoltan G. Levay1, Nino Panagia1, William B. Sparks1, Sumner Starrfield3, R. Mark Wagner4, R. L. M. Corradi5, and U. Munari6 Abstract. The outburst of the unusual variable star V838 Monocero- tis is being accompanied by the most spectacular display of light echoes in the history of astronomy. We have imaged the echoes on 5 occasions in 2002 with the Hubble Space Telescope and its Advanced Camera for Surveys. Analysis of the angular expansion rates and polarimetry data yields a direct geometric distance (6 kpc), and establishes that the star was extremely luminous at the maximum of its outburst. Unlike a classi- cal nova, V838 Mon has remained a very cool red supergiant, and is now producing copious amounts of dust. The dust illuminated in the echoes was presumably ejected during previous similar outbursts. This event thus bears some similarities to the proto-PN ejection process from more normal AGB and post-AGB stars, and is of relevance to this conference. Light-echo imaging allows construction of fully 3-D maps of the dust dis- tribution, and we present a map based on these early observations. The dust is already seen to be highly non-spherical and non-homogeneous, similar to the structure inferred for many proto-PNe. 1. The Light-Echo Phenomenon A light echo is produced when a wave of illumination from a stellar outburst sweeps out into space. -
Latest Views of the V838 Monocerotis Light Echo from Hubble 26 October 2006
Latest views of the V838 Monocerotis light echo from Hubble 26 October 2006 The NASA/ESA Hubble Space Telescope has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique "thin-section" through the interstellar dust around the star. This release shows new images of the light echo from the Hubble Advanced Camera for Surveys taken in November 2005 (left) and again in September 2006 (right). The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars. The Hubble observations have been used to These images show the evolution of the light echo around the star V838 in the constellation of Monoceros. determine the distance to V838 Mon, using a They were taken by the Hubble Advanced Camera for technique based on the polarisation of the reflected Surveys in November 2005 (left) and again in light. Hubble has polarising filters that only pass September 2006 (right). The numerous whorls and light that vibrates at certain angles. This method eddies in the interstellar dust are particularly noticeable. yields a distance of 20,000 light-years for V838 Possibly they have been produced by the effects of Mon, suggesting that, during its outburst, V838 Mon magnetic fields in the space between the stars. Credit: was one of the brightest stars in the entire Milky NASA, ESA and H. Bond (STScI) Way. Although the reason for the eruption is still unclear, some astronomers have suggested it might have resulted from the collision of two stars. -
Observational Selection Bias Affecting the Determination of the Extragalactic Distance Scale
P1: JER/MBL/mkv/sny P2: MBL/plb QC: MBL/abe T1: MBL January 9, 1998 15:15 Annual Reviews AR037-04 Annu. Rev. Astron. Astrophys. 1997. 35:101–36 Copyright c 1997 by Annual Reviews Inc. All rights reserved OBSERVATIONAL SELECTION BIAS AFFECTING THE DETERMINATION OF THE EXTRAGALACTIC DISTANCE SCALE P. Teerikorpi Tuorla Observatory, Turku University, FIN-21500 Piikki¨o, Finland; e-mail: [email protected].fi KEY WORDS: galaxies, Tully-Fisher relation, Malmquist bias, distance scale, cosmology ABSTRACT The influence of Malmquist bias on the studies of extragalactic distances is re- viewed, with brief glimpses of the history from Kapteyn to Scott. Special attention is paid to two kinds of biases, for which the names Malmquist biases of the first and second kind are proposed. The essence of these biases and the situations where they occur are discussed. The bias of the first kind is related to the classical Malmquist bias (involving the “volume effect”), while the bias of the second kind appears when standard candles are observed at different (true) distances, whereby magnitude limit cuts away a part of the luminosity function. In particular, study of the latter bias in distance indicators such as Tully Fisher, available for large fundamental samples of galaxies, allows construction of an unbiased absolute distance scale in the by University of Wisconsin - Madison on 03/12/08. For personal use only. local galaxy universe where approximate kinematic relative distances can be de- rived. Such investigations, using the method of normalized distances or of the Spaenhauer diagram, support the linearity of the Hubble law and make it possible Annu. -
Ten Years Hubble Space Telescope Editorial
INTERNATIONAL SPACE SCIENCE INSTITUTE Published by the Association Pro ISSI No 12, June 2004 Ten Years Hubble Space Telescope Editorial Give me the material, and I will century after Kant and a telescope Impressum build a world out of it! built another century later. The Hubble Space Telescope has revo- Immanuel Kant (1724–1804), the lutionised our understanding of great German philosopher, began the cosmos much the same as SPATIUM his scientific career on the roof of Kant’s theoretical reflections did. Published bythe the Friedrich’s College of Königs- Observing the heavenly processes, Association Pro ISSI berg, where a telescope allowed so far out of anyhuman reach, twice a year him to take a glance at the Uni- gives men the feeling of the cos- verse inspiring him to his first mos’ overwhelming forces and masterpiece, the “Universal Nat- beauties from which Immanuel INTERNATIONAL SPACE ural History and Theory of Heav- Kant derived the order for a ra- SCIENCE en” (1755). Applying the Newton- tional and moral human behav- INSTITUTE ian principles of mechanics, it is iour: “the starry heavens above me Association Pro ISSI the result of systematic thinking, and the moral law within me...”. Hallerstrasse 6,CH-3012 Bern “rejecting with the greatest care all Phone +41 (0)31 631 48 96 arbitrary fictions”. In his later Cri- Who could be better qualified to Fax +41 (0)31 631 48 97 tique of the Pure Reason (1781) rate the Hubble Space Telescope’s Kant maintained that the human impact on astrophysics and cos- President intellect does not receive the laws mology than Professor Roger M. -
Kinematics of the Local Universe. VIII. Normalized Distances As a Tool For
Kinematics of the local universe. VIII. Normalized distances as a tool for Malmquist bias corrections and application to the study of peculiar velocities in the direction of the Perseus-Pisces and the Great Attractor regions G. Theureau, Stéphane Rauzy, L. Bottinelli, L. Gouguenheim To cite this version: G. Theureau, Stéphane Rauzy, L. Bottinelli, L. Gouguenheim. Kinematics of the local universe. VIII. Normalized distances as a tool for Malmquist bias corrections and application to the study of peculiar velocities in the direction of the Perseus-Pisces and the Great Attractor regions. Astronomy and Astrophysics - A&A, EDP Sciences, 1998, 340, pp.21-34. hal-01704535 HAL Id: hal-01704535 https://hal.archives-ouvertes.fr/hal-01704535 Submitted on 30 Apr 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Astron. Astrophys. 340, 21–34 (1998) ASTRONOMY AND ASTROPHYSICS Kinematics of the local universe VIII. Normalized distances as a tool for Malmquist bias corrections and application to the study of peculiar velocities in the direction of the Perseus-Pisces and the Great Attractor regions G. Theureau1,2, S. Rauzy4, L. Bottinelli1,3, and L. Gouguenheim1,3 1 Observatoire de Paris/Meudon, ARPEGES/CNRS URA1757, F-92195 Meudon Principal Cedex, France 2 Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli, Italy 3 Universite´ Paris-Sud, F-91405 Orsay, France 4 Centre de Physique Theorique´ - C.N.R.S., Luminy Case 907, F-13288 Marseille Cedex 9, France Received 14 January 1998 / Accepted 8 September 1998 Abstract. -
Discovery of Multiple Shells Around V838 Monocerotis
A&A 427, 193–197 (2004) Astronomy DOI: 10.1051/0004-6361:20041388 & c ESO 2004 Astrophysics Discovery of multiple shells around V838 Monocerotis J. Th. van Loon, A. Evans, M. T. Rushton, and B. Smalley Astrophysics Group, School of Chemistry and Physics, Keele University, Staffordshire ST5 5BG, UK e-mail: [email protected] Received 15 April 2004 / Accepted 3 July 2004 Abstract. We report the discovery of multiple shells around the eruptive variable star V838 Mon. Two dust shells are seen in IRAS and MSX images, which themselves are situated in a shell of CO. This securely establishes V838 Mon as an evolved object. We revisit the light echo, which arises from scattering off the innermost resolved dust shell, to infer a distance to V838 Mon of ∼>5.5 kpc. The dynamical timescales of the ejected shells, location in the Milky Way and inferred luminosity are consistent with V838 Mon being a low-mass AGB star experiencing thermal pulses of which the 2002 eruption might have sent the star into the post-AGB phase. This scenario, however, is inconsistent with the presence of a (young and massive) B3 V companion. Key words. stars: AGB and post-AGB – stars: circumstellar matter – stars: distances – stars: individual: V838 Monocerotis – stars: mass-loss – stars: peculiar 1. Introduction interstellar medium, emits at far-IR wavelengths. The sky around V838 Mon is included in both the IRAS all sky survey V838 Monocerotis was discovered on January 6, 2002, (Brown (12, 25, 60 and 100 µm), and the Galactic plane survey by the 2002) as a new eruptive variable star, and peaked at m V MSX in several mid-IR bands of which band A (8.3 µm) was 7 mag on February 5, 2002. -
Science with the Square Kilometer Array
Science with the Square Kilometer Array edited by: A.R. Taylor and R. Braun March 1999 Cover image: The Hubble Deep Field Courtesy of R. Williams and the HDF Team (ST ScI) and NASA. Contents Executive Summary 6 1 Introduction 10 1.1 ANextGenerationRadioObservatory . 10 1.2 The Square Kilometre Array Concept . 12 1.3 Instrumental Sensitivity . 15 1.4 Contributors................................ 18 2 Formation and Evolution of Galaxies 20 2.1 TheDawnofGalaxies .......................... 20 2.1.1 21-cm Emission and Absorption Mechanisms . 22 2.1.2 PreheatingtheIGM ....................... 24 2.1.3 Scenarios: SKA Imaging of Cosmological H I .......... 25 2.2 LargeScale Structure and GalaxyEvolution . ... 28 2.2.1 A Deep SKA H I Pencil Beam Survey . 29 2.2.2 Large scale structure studies from a shallow, wide area survey 31 2.2.3 The Lyα forest seen in the 21-cm H I line............ 32 2.2.4 HighRedshiftCO......................... 33 2.3 DeepContinuumFields. .. .. 38 2.3.1 ExtragalacticRadioSources . 38 2.3.2 The SubmicroJansky Sky . 40 2.4 Probing Dark Matter with Gravitational Lensing . .... 42 2.5 ActivityinGalacticNuclei . 46 2.5.1 The SKA and Active Galactic Nuclei . 47 2.5.2 Sensitivity of the SKA in VLBI Arrays . 52 2.6 Circum-nuclearMegaMasers . 53 2.6.1 H2Omegamasers ......................... 54 2.6.2 OHMegamasers.......................... 55 2.6.3 FormaldehydeMegamasers. 55 2.6.4 The Impact of the SKA on Megamaser Studies . 56 2.7 TheStarburstPhenomenon . 57 2.7.1 TheimportanceofStarbursts . 58 2.7.2 CurrentRadioStudies . 58 2.7.3 The Potential of SKA for Starburst Studies . 61 3 4 CONTENTS 2.8 InterstellarProcesses . -
Geometrical Tests of Cosmological Models III. the Cosmology- Evolution Diagram at Z = 1
Haverford College Haverford Scholarship Faculty Publications Astronomy 2007 Geometrical tests of cosmological models III. The Cosmology- evolution diagram at z = 1 Karen Masters Haverford College, [email protected] C. Marinoni A. Saintonge T. Contini Follow this and additional works at: https://scholarship.haverford.edu/astronomy_facpubs Repository Citation Masters, K.;et al. (2007) "Geometrical tests of cosmological models III. The Cosmology-evolution diagram at z = 1." Astronomy & Astrophysics, 478(1):71-81. This Journal Article is brought to you for free and open access by the Astronomy at Haverford Scholarship. It has been accepted for inclusion in Faculty Publications by an authorized administrator of Haverford Scholarship. For more information, please contact [email protected]. A&A 478, 71–81 (2008) Astronomy DOI: 10.1051/0004-6361:20077118 & c ESO 2008 Astrophysics Geometrical tests of cosmological models III. The Cosmology-evolution diagram at z =1 C. Marinoni1, A. Saintonge2, T. Contini3, C. J. Walcher4, R. Giovanelli2,M.P.Haynes2, K. L. Masters5, O. Ilbert4,A.Iovino6,V.LeBrun4,O.LeFevre4, A. Mazure4, L. Tresse4, J.-M. Virey1, S. Bardelli7, D. Bottini8, B. Garilli8, G. Guzzo9, D. Maccagni8,J.P.Picat3, R. Scaramella9, M. Scodeggio8,P.Taxil1, G. Vettolani10, A. Zanichelli10, and E. Zucca7 1 Centre de Physique Théorique, CNRS-Université de Provence, Case 907, 13288 Marseille, France e-mail: [email protected] 2 Department of Astronomy, Cornell University, Ithaca, NY 14853, USA 3 Laboratoire d’Astrophysique de l’Observatoire