An Introduction to Our Universe
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Constructing a Galactic Coordinate System Based on Near-Infrared and Radio Catalogs
A&A 536, A102 (2011) Astronomy DOI: 10.1051/0004-6361/201116947 & c ESO 2011 Astrophysics Constructing a Galactic coordinate system based on near-infrared and radio catalogs J.-C. Liu1,2,Z.Zhu1,2, and B. Hu3,4 1 Department of astronomy, Nanjing University, Nanjing 210093, PR China e-mail: [jcliu;zhuzi]@nju.edu.cn 2 key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210093, PR China 3 Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, PR China 4 Graduate School of Chinese Academy of Sciences, Beijing 100049, PR China e-mail: [email protected] Received 24 March 2011 / Accepted 13 October 2011 ABSTRACT Context. The definition of the Galactic coordinate system was announced by the IAU Sub-Commission 33b on behalf of the IAU in 1958. An unrigorous transformation was adopted by the Hipparcos group to transform the Galactic coordinate system from the FK4-based B1950.0 system to the FK5-based J2000.0 system or to the International Celestial Reference System (ICRS). For more than 50 years, the definition of the Galactic coordinate system has remained unchanged from this IAU1958 version. On the basis of deep and all-sky catalogs, the position of the Galactic plane can be revised and updated definitions of the Galactic coordinate systems can be proposed. Aims. We re-determine the position of the Galactic plane based on modern large catalogs, such as the Two-Micron All-Sky Survey (2MASS) and the SPECFIND v2.0. This paper also aims to propose a possible definition of the optimal Galactic coordinate system by adopting the ICRS position of the Sgr A* at the Galactic center. -
Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects
Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Porto Alegre 2017 Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Dissertação elaborada sob orientação do Prof. Dr. Eduardo Luis Damiani Bica, co- orientação do Prof. Dr. Charles José Bon- ato e apresentada ao Instituto de Física da Universidade Federal do Rio Grande do Sul em preenchimento do requisito par- cial para obtenção do título de Mestre em Física. Porto Alegre 2017 Acknowledgements To my parents, who supported me and made this possible, in a time and place where being in a university was just a distant dream. To my dearest friends Elisabeth, Robert, Augusto, and Natália - who so many times helped me go from "I give up" to "I’ll try once more". To my cats Kira, Fen, and Demi - who lazily join me in bed at the end of the day, and make everything worthwhile. "But, first of all, it will be necessary to explain what is our idea of a cluster of stars, and by what means we have obtained it. For an instance, I shall take the phenomenon which presents itself in many clusters: It is that of a number of lucid spots, of equal lustre, scattered over a circular space, in such a manner as to appear gradually more compressed towards the middle; and which compression, in the clusters to which I allude, is generally carried so far, as, by imperceptible degrees, to end in a luminous center, of a resolvable blaze of light." William Herschel, 1789 Abstract We provide a sample of 170 Galactic Globular Clusters (GCs) and analyse its spatial distribution properties. -
The Large Scale Universe As a Quasi Quantum White Hole
International Astronomy and Astrophysics Research Journal 3(1): 22-42, 2021; Article no.IAARJ.66092 The Large Scale Universe as a Quasi Quantum White Hole U. V. S. Seshavatharam1*, Eugene Terry Tatum2 and S. Lakshminarayana3 1Honorary Faculty, I-SERVE, Survey no-42, Hitech city, Hyderabad-84,Telangana, India. 2760 Campbell Ln. Ste 106 #161, Bowling Green, KY, USA. 3Department of Nuclear Physics, Andhra University, Visakhapatnam-03, AP, India. Authors’ contributions This work was carried out in collaboration among all authors. Author UVSS designed the study, performed the statistical analysis, wrote the protocol, and wrote the first draft of the manuscript. Authors ETT and SL managed the analyses of the study. All authors read and approved the final manuscript. Article Information Editor(s): (1) Dr. David Garrison, University of Houston-Clear Lake, USA. (2) Professor. Hadia Hassan Selim, National Research Institute of Astronomy and Geophysics, Egypt. Reviewers: (1) Abhishek Kumar Singh, Magadh University, India. (2) Mohsen Lutephy, Azad Islamic university (IAU), Iran. (3) Sie Long Kek, Universiti Tun Hussein Onn Malaysia, Malaysia. (4) N.V.Krishna Prasad, GITAM University, India. (5) Maryam Roushan, University of Mazandaran, Iran. Complete Peer review History: http://www.sdiarticle4.com/review-history/66092 Received 17 January 2021 Original Research Article Accepted 23 March 2021 Published 01 April 2021 ABSTRACT We emphasize the point that, standard model of cosmology is basically a model of classical general relativity and it seems inevitable to have a revision with reference to quantum model of cosmology. Utmost important point to be noted is that, ‘Spin’ is a basic property of quantum mechanics and ‘rotation’ is a very common experience. -
Modeling and Interpretation of the Ultraviolet Spectral Energy Distributions of Primeval Galaxies
Ecole´ Doctorale d'Astronomie et Astrophysique d'^Ile-de-France UNIVERSITE´ PARIS VI - PIERRE & MARIE CURIE DOCTORATE THESIS to obtain the title of Doctor of the University of Pierre & Marie Curie in Astrophysics Presented by Alba Vidal Garc´ıa Modeling and interpretation of the ultraviolet spectral energy distributions of primeval galaxies Thesis Advisor: St´ephane Charlot prepared at Institut d'Astrophysique de Paris, CNRS (UMR 7095), Universit´ePierre & Marie Curie (Paris VI) with financial support from the European Research Council grant `ERC NEOGAL' Composition of the jury Reviewers: Alessandro Bressan - SISSA, Trieste, Italy Rosa Gonzalez´ Delgado - IAA (CSIC), Granada, Spain Advisor: St´ephane Charlot - IAP, Paris, France President: Patrick Boisse´ - IAP, Paris, France Examinators: Jeremy Blaizot - CRAL, Observatoire de Lyon, France Vianney Lebouteiller - CEA, Saclay, France Dedicatoria v Contents Abstract vii R´esum´e ix 1 Introduction 3 1.1 Historical context . .4 1.2 Early epochs of the Universe . .5 1.3 Galaxytypes ......................................6 1.4 Components of a Galaxy . .8 1.4.1 Classification of stars . .9 1.4.2 The ISM: components and phases . .9 1.4.3 Physical processes in the ISM . 12 1.5 Chemical content of a galaxy . 17 1.6 Galaxy spectral energy distributions . 17 1.7 Future observing facilities . 19 1.8 Outline ......................................... 20 2 Modeling spectral energy distributions of galaxies 23 2.1 Stellar emission . 24 2.1.1 Stellar population synthesis codes . 24 2.1.2 Evolutionary tracks . 25 2.1.3 IMF . 29 2.1.4 Stellar spectral libraries . 30 2.2 Absorption and emission in the ISM . 31 2.2.1 Photoionization code: CLOUDY ....................... -
Arxiv:1802.07727V1 [Astro-Ph.HE] 21 Feb 2018 Tion Systems to Standard Candles in Cosmology (E.G., Wijers Et Al
Astronomy & Astrophysics manuscript no. XSGRB_sample_arxiv c ESO 2018 2018-02-23 The X-shooter GRB afterglow legacy sample (XS-GRB)? J. Selsing1;??, D. Malesani1; 2; 3,y, P. Goldoni4,y, J. P. U. Fynbo1; 2,y, T. Krühler5,y, L. A. Antonelli6,y, M. Arabsalmani7; 8, J. Bolmer5; 9,y, Z. Cano10,y, L. Christensen1, S. Covino11,y, P. D’Avanzo11,y, V. D’Elia12,y, A. De Cia13, A. de Ugarte Postigo1; 10,y, H. Flores14,y, M. Friis15; 16, A. Gomboc17, J. Greiner5, P. Groot18, F. Hammer14, O.E. Hartoog19,y, K. E. Heintz1; 2; 20,y, J. Hjorth1,y, P. Jakobsson20,y, J. Japelj19,y, D. A. Kann10,y, L. Kaper19, C. Ledoux9, G. Leloudas1, A.J. Levan21,y, E. Maiorano22, A. Melandri11,y, B. Milvang-Jensen1; 2, E. Palazzi22, J. T. Palmerio23,y, D. A. Perley24,y, E. Pian22, S. Piranomonte6,y, G. Pugliese19,y, R. Sánchez-Ramírez25,y, S. Savaglio26, P. Schady5, S. Schulze27,y, J. Sollerman28, M. Sparre29,y, G. Tagliaferri11, N. R. Tanvir30,y, C. C. Thöne10, S.D. Vergani14,y, P. Vreeswijk18; 26,y, D. Watson1; 2,y, K. Wiersema21; 30,y, R. Wijers19, D. Xu31,y, and T. Zafar32 (Affiliations can be found after the references) Received/ accepted ABSTRACT In this work we present spectra of all γ-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31=03=2017. In total, we obtained spectroscopic observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. -
Planck: Dust Emission in Galactic Environments
Planck’s impact on interstellar medium science new insights and new directions Peter Martin CITA, University of Toronto On behalf of the Planck collaboration Perspective Wasted opportunity Fractionally, there are not many baryons, and even though Planck has given us a bit more, still most of these baryons are not in galaxies. Extragalactic context: Ellipticals Elliptical galaxies: red and dead. Very little ISM: gas and dust used up and/or expelled. NGC 4660 in the Virgo Cluster Hubble Space Telescope Elliptical envy With no ISM – no Galactic foregrounds – imagine the clear view of the CMB from inside such a galaxy! Galactic centre microwave haze Planck intermediate results. IX. Detection of the Galactic haze with Planck Here be monsters Non-thermal emission. Relativistic particles. Extragalactic context: Spirals Spiral galaxies: gas and dust available in an ISM for ongoing star formation NGC 3982 HST Dusty disk – like we live in Spiral galaxy: edge on, dust lane In our Galaxy, a foreground to the CMB. NGC 4565 CFHT An overarching question in interstellar medium (ISM) science Why is there still an ISM in the Milky Way in which stars are continually forming? How does the Milky Way tick? Curious Expeditions: Augustinian friar’s astrological clock. Spirals: gratitude Would we be able to figure out, ab initio and theoretically, how stars form, if we did not have an ISM “up close” in the Galaxy and so the empirical evidence and constraints? Or more to the point, could we answer why star formation is so disruptive of the ISM and so inefficient? Or would we have any fun at all? An ISM research program Galactic ecology: the cycling of the ISM from the diffuse atomic phase to dense molecular clouds, the sites of star formation/evolution, and back. -
Galaxies Through Cosmic Time Illuminated by Gamma-Ray Bursts and Quasars
Galaxies through Cosmic Time Illuminated by Gamma-Ray Bursts and Quasars Kasper Elm Heintz arXiv:1910.09849v1 [astro-ph.GA] 22 Oct 2019 Faculty of Physical Sciences University of Iceland 2019 Galaxies through Cosmic Time Illuminated by Gamma-Ray Bursts and Quasars Kasper Elm Heintz Dissertation submitted in partial fulfillment of a Philosophiae Doctor degree in Physics PhD Committee Prof. Páll Jakobsson (supervisor) Assoc. Prof. Jesús Zavala Prof. Emeritus Einar H. Guðmundsson Opponents Prof. J. Xavier Prochaska Dr. Valentina D’Odorico Faculty of Physical Sciences School of Engineering and Natural Sciences University of Iceland Reykjavik, July 2019 Galaxies through Cosmic Time Illuminated by Gamma-Ray Bursts and Quasars Dissertation submitted in partial fulfillment of a Philosophiae Doctor degree in Physics Copyright © Kasper Elm Heintz 2019 All rights reserved Faculty of Physical Sciences School of Engineering and Natural Sciences University of Iceland Dunhagi 107, Reykjavik Iceland Telephone: 525-4000 Bibliographic information: Kasper Elm Heintz, 2019, Galaxies through Cosmic Time Illuminated by Gamma-Ray Bursts and Quasars, PhD disserta- tion, Faculty of Physical Sciences, University of Iceland, 71 pp. ISBN 978-9935-9473-3-8 Printing: Háskólaprent Reykjavik, Iceland, July 2019 Contents Abstract v Útdráttur vii Acknowledgments ix 1 Introduction 1 1.1 The nature of GRBs and quasars 1 1.1.1 GRB optical afterglows...................................2 1.1.2 Late-stage emission components associated with GRBs..............3 1.1.3 Quasar classification and selection............................4 1.1.4 GRBs and quasars as cosmic probes..........................5 1.2 Damped Lyman-α absorbers 7 1.2.1 Gas-phase abundances and kinematics........................ 10 1.2.2 The effect of dust..................................... -
Some Astrophysical and Cosmological Findings from TGD Point of View
Some astrophysical and cosmological findings from TGD point of view M. Pitk¨anen Email: [email protected]. http://tgdtheory.com/. June 20, 2019 Abstract There are five rather recent findings not easy to understand in the framework of standard astrophysics and cosmology. The first finding is that the model for the absorption of dark matter by blackholes predicts must faster rate than would be consistent with observations. Second finding is that Milky Way has large void extending from 150 ly up to 8,000 light years. Third finding is the existence of galaxy estimated to have mass of order Milky Way mass but for which 98 per cent of mass within half-light radius is estimated to be dark in halo model. The fourth finding confirms the old finding that the value of Hubble constant is 9 per cent larger in short scales (of order of the size large voids) than in cosmological scales. The fifth finding is that astrophysical object do not co-expand but only co-move in cosmic expansion. TGD suggests an explanation for the two first observation in terms of dark matter with gravitational Planck constant hgr, which is very large so that dark matter is at some level quantum coherent even in galactic scales. Second and third findings can be explained using TGD based model of dark matter and energy assigning them to long cosmic strings having galaxies along them like pearls in necklace. Fourth finding can be understood in terms of many-sheeted space-time. The space-time sheets assignable to large void and entire cosmology have different Hubble constants and expansion rate. -
Structure, Kinematics and Dynamics of the Galaxy
Outline Structure of the Galaxy Kinematics of the Galaxy Galactic dynamics STRUCTURE OF GALAXIES 1. Structure, kinematics and dynamics of the Galaxy Piet van der Kruit Kapteyn Astronomical Institute University of Groningen the Netherlands February 2010 Piet van der Kruit, Kapteyn Astronomical Institute Structure, kinematics and dynamics of the Galaxy Outline Structure of the Galaxy Kinematics of the Galaxy Galactic dynamics Outline Structure of the Galaxy History All-sky pictures Kinematics of the Galaxy Differential rotation Local approximations and Oort constants Rotation curves and mass distributions Galactic dynamics Fundamental equations Epicycle orbits Vertical motion Piet van der Kruit, Kapteyn Astronomical Institute Structure, kinematics and dynamics of the Galaxy Outline Structure of the Galaxy History Kinematics of the Galaxy All-sky pictures Galactic dynamics Structure of the Galaxy Piet van der Kruit, Kapteyn Astronomical Institute Structure, kinematics and dynamics of the Galaxy Outline Structure of the Galaxy History Kinematics of the Galaxy All-sky pictures Galactic dynamics History Our Galaxy can be seen on the sky as the Milky Way, a band of faint light. Piet van der Kruit, Kapteyn Astronomical Institute Structure, kinematics and dynamics of the Galaxy Outline Structure of the Galaxy History Kinematics of the Galaxy All-sky pictures Galactic dynamics The earliest attempts to study the structure of the Milky Way Galaxy (the Sidereal System; really the whole universe) on a global scale were based on star counts. William Herschel (1738 – 1822) performed such “star gauges” and assumed that (1) all stars have equal intrinsic luminostities and (2) he could see stars out ot the edges of the system. -
Disk Heating, Galactoseismology, and the Formation of Stellar Halos
galaxies Article Disk Heating, Galactoseismology, and the Formation of Stellar Halos Kathryn V. Johnston 1,*,†, Adrian M. Price-Whelan 2,†, Maria Bergemann 3, Chervin Laporte 1, Ting S. Li 4, Allyson A. Sheffield 5, Steven R. Majewski 6, Rachael S. Beaton 7, Branimir Sesar 3 and Sanjib Sharma 8 1 Department of Astronomy, Columbia University, 550 W 120th st., New York, NY 10027, USA; cfl[email protected] 2 Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544, USA; [email protected] 3 Max Planck Institute for Astronomy, Heidelberg 69117, Germany; [email protected] (M.B.); [email protected] (B.S.) 4 Fermi National Accelerator Laboratory, P. O. Box 500, Batavia, IL 60510, USA; [email protected] 5 Department of Natural Sciences, LaGuardia Community College, City University of New York, 31-10 Thomson Ave., Long Island City, NY 11101, USA; asheffi[email protected] 6 Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904, USA; [email protected] 7 The Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101, USA; [email protected] 8 Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia; [email protected] * Correspondence: [email protected]; Tel.: +1-212-854-3884 † These authors contributed equally to this work. Academic Editors: Duncan A. Forbes and Ericson D. Lopez Received: 1 July 2017; Accepted: 14 August 2017; Published: 26 August 2017 Abstract: Deep photometric surveys of the Milky Way have revealed diffuse structures encircling our Galaxy far beyond the “classical” limits of the stellar disk. -
Serendipitious 2MASS Discoveries Near the Galactic Plane
Serendipitous 2MASS Discoveries Near the Galactic Plane: A Spiral Galaxy and Two Globular Clusters Robert L. Hurt, Tom H. Jarrett, J. Davy Kirkpatrick, Roc M. Cutri Infrared Processing & Analysis Center, MS 100-22, California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA 91125 [email protected], [email protected], [email protected], [email protected] Stephen E. Schneider, Mike Skrutskie Astronomy Program, University of Massachusetts, Amherst, MA 01003 [email protected], [email protected] Willem van Driel United Scientifique Nançay, Obs. de Paris–Meudon, Meudon Cedex, CA 92195, France [email protected] Abstract We present the basic properties of three objects near the Galactic Plane—a large galaxy and two candidate globular clusters—discovered in the Two Micron All Sky Survey (2MASS) dataset. All were noted during spot-checks of the data during 2MASS quality assurance reviews. The galaxy is a late-type spiral galaxy (Sc–Sd), ~11 Mpc distant, at l = 236.82°, b = -1.86°. From its observed angular extent of 6.3' in the near infrared, we estimate an extinction-corrected optical diameter of ~9.5', making it larger than most Messier galaxies. The candidate globular clusters are ~2–3’ in extent and are hidden optically behind foreground extinctions of Av ~18–21 mag at l ~ 10°, b ~ 0°. These chance discoveries were not the result of any kind of systematic search but they do hint at the wealth of obscured sources of all kinds, many previously unknown, that are in the 2MASS dataset. Key words: galaxies: photometry—galaxies: spiral—(Galaxy:) globular clusters: general—surveys—infrared radiation 1. -
The Galactic Contribution to Icecube's Astrophysical Neutrino Flux
Prepared for submission to JCAP The Galactic Contribution to IceCube’s Astrophysical Neutrino Flux Peter B. Denton,a,1 Danny Marfatia,b Thomas J. Weilerc aNiels Bohr International Academy, University of Copenhagen, The Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen, Denmark bDepartment of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822, USA cDepartment of Physics & Astronomy, Vanderbilt University, Nashville, TN 37235, USA E-mail: [email protected], [email protected], [email protected] Abstract. High energy neutrinos have been detected by IceCube, but their origin remains a mystery. Determining the sources of this flux is a crucial first step towards multi-messenger studies. In this work we systematically compare two classes of sources with the data: Galactic and extragalactic. We assume that the neutrino sources are distributed according to a class of Galactic models. We build a likelihood function on an event by event basis including energy, event topology, absorption, and direction information. We present the probability that each high energy event with deposited energy Edep > 60 TeV in the HESE sample is Galactic, extragalactic, or background. For Galactic models considered the Galactic fraction of the astrophysical flux has a best fit value of 1.3% and is < 9.5% at 90% CL. A zero Galactic flux is allowed at < 1σ. Keywords: neutrino astronomy, neutrino experiments, galaxy morphology ArXiv ePrint: 1703.09721 arXiv:1703.09721v3 [astro-ph.HE] 8 Aug 2017 1ORCID: 0000-0002-5209-872X Contents 1 Introduction 1 2 IceCube HESE Dataset 2 3 Galactic and Extragalactic Distributions 4 4 Likelihood 4 5 Results 6 6 Discussion and Conclusions 8 7 Acknowledgements 9 A von Mises-Fisher Distribution 10 1 Introduction IceCube has reported the detection of high energy astrophysical neutrinos for the first time [1].