Laboratory Astrophysics: from Observations to Interpretation
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Intelligent Design, Abiogenesis, and Learning from History: Dennis R
Author Exchange Intelligent Design, Abiogenesis, and Learning from History: Dennis R. Venema A Reply to Meyer Dennis R. Venema Weizsäcker’s book The World View of Physics is still keeping me very busy. It has again brought home to me quite clearly how wrong it is to use God as a stop-gap for the incompleteness of our knowledge. If in fact the frontiers of knowledge are being pushed back (and that is bound to be the case), then God is being pushed back with them, and is therefore continually in retreat. We are to find God in what we know, not in what we don’t know; God wants us to realize his presence, not in unsolved problems but in those that are solved. Dietrich Bonhoeffer1 am thankful for this opportunity to nature, is the result of intelligence. More- reply to Stephen Meyer’s criticisms over, this assertion is proffered as the I 2 of my review of his book Signature logical basis for inferring design for the in the Cell (hereafter Signature). Meyer’s origin of biological information: if infor- critiques of my review fall into two gen- mation only ever arises from intelli- eral categories. First, he claims I mistook gence, then the mere presence of Signature for an argument against bio- information demonstrates design. A few logical evolution, rendering several of examples from Signature make the point my arguments superfluous. Secondly, easily: Meyer asserts that I have failed to refute … historical scientists can show that his thesis by not providing a “causally a presently acting cause must have adequate alternative explanation” for the been present in the past because the origin of life in that the few relevant cri- proposed candidate is the only known tiques I do provide are “deeply flawed.” cause of the effect in question. -
Bayesian Analysis of the Astrobiological Implications of Life's
Bayesian analysis of the astrobiological implications of life's early emergence on Earth David S. Spiegel ∗ y, Edwin L. Turner y z ∗Institute for Advanced Study, Princeton, NJ 08540,yDept. of Astrophysical Sciences, Princeton Univ., Princeton, NJ 08544, USA, and zInstitute for the Physics and Mathematics of the Universe, The Univ. of Tokyo, Kashiwa 227-8568, Japan Submitted to Proceedings of the National Academy of Sciences of the United States of America Life arose on Earth sometime in the first few hundred million years Any inferences about the probability of life arising (given after the young planet had cooled to the point that it could support the conditions present on the early Earth) must be informed water-based organisms on its surface. The early emergence of life by how long it took for the first living creatures to evolve. By on Earth has been taken as evidence that the probability of abiogen- definition, improbable events generally happen infrequently. esis is high, if starting from young-Earth-like conditions. We revisit It follows that the duration between events provides a metric this argument quantitatively in a Bayesian statistical framework. By (however imperfect) of the probability or rate of the events. constructing a simple model of the probability of abiogenesis, we calculate a Bayesian estimate of its posterior probability, given the The time-span between when Earth achieved pre-biotic condi- data that life emerged fairly early in Earth's history and that, billions tions suitable for abiogenesis plus generally habitable climatic of years later, curious creatures noted this fact and considered its conditions [5, 6, 7] and when life first arose, therefore, seems implications. -
Large Molecules in the Envelope Surrounding IRC+10216
Mon. Not. R. Astron. Soc. 316, 195±203 (2000) Large molecules in the envelope surrounding IRC110216 T. J. Millar,1 E. Herbst2w and R. P. A. Bettens3 1Department of Physics, UMIST, PO Box 88, Manchester M60 1QD 2Departments of Physics and Astronomy, The Ohio State University, Columbus, OH 43210, USA 3Research School of Chemistry, Australian National University, ACT 0200, Australia Accepted 2000 February 22. Received 2000 February 21; in original form 2000 January 21 ABSTRACT A new chemical model of the circumstellar envelope surrounding the carbon-rich star IRC110216 is developed that includes carbon-containing molecules with up to 23 carbon atoms. The model consists of 3851 reactions involving 407 gas-phase species. Sizeable abundances of a variety of large molecules ± including carbon clusters, unsaturated hydro- carbons and cyanopolyynes ± have been calculated. Negative molecular ions of chemical 2 2 formulae Cn and CnH 7 # n # 23 exist in considerable abundance, with peak concen- trations at distances from the central star somewhat greater than their neutral counterparts. The negative ions might be detected in radio emission, or even in the optical absorption of background field stars. The calculated radial distributions of the carbon-chain CnH radicals are looked at carefully and compared with interferometric observations. Key words: molecular data ± molecular processes ± circumstellar matter ± stars: individual: IRC110216 ± ISM: molecules. synthesis of fullerenes in the laboratory through chains and rings 1 INTRODUCTION is well-known (von Helden, Notts & Bowers 1993; Hunter et al. The possible production of large molecules in assorted astronomi- 1994), the individual reactions have not been elucidated. Bettens cal environments is a problem of considerable interest. -
Organics in the Solar System
Organics in the Solar System Sun Kwok1,2 1 Laboratory for Space Research, The University of Hong Kong, Hong Kong, China 2 Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, B.C., Canada [email protected]; [email protected] ABSTRACT Complex organics are now commonly found in meteorites, comets, asteroids, planetary satellites, and interplanetary dust particles. The chemical composition and possible origin of these organics are presented. Specifically, we discuss the possible link between Solar System organics and the complex organics synthesized during the late stages of stellar evolution. Implications of extraterrestrial organics on the origin of life on Earth and the possibility of existence of primordial organics on Earth are also discussed. Subject headings: meteorites, organics, stellar evolution, origin of life arXiv:1901.04627v1 [astro-ph.EP] 15 Jan 2019 Invited review presented at the International Symposium on Lunar and Planetary Science, accepted for publication in Research in Astronomy and Astrophysics. –2– 1. Introduction In the traditional picture of the Solar System, planets, asteroids, comets and planetary satellites were formed from a well-mixed primordial nebula of chemically and isotopically uniform composition. The primordial solar nebula was believed to be initially composed of only atomic elements synthesized by previous generations of stars, and current Solar System objects later condensed out of this homogeneous gaseous nebula. Gas, ice, metals, and minerals were assumed to be the primarily constituents of planetary bodies (Suess 1965). Although the presence of organics in meteorites was hinted as early as the 19th century (Berzelius 1834), the first definite evidence for the presence of extraterrestrial organic matter in the Solar System was the discovery of paraffins in the Orgueil meteorites (Nagy et al. -
Origin and Evolution of Carbonaceous Presolar Grains in Stellar Environments
Bernatowicz et al.: Origin and Evolution of Presolar Grains 109 Origin and Evolution of Carbonaceous Presolar Grains in Stellar Environments Thomas J. Bernatowicz Washington University Thomas K. Croat Washington University Tyrone L. Daulton Naval Research Laboratory Laboratory microanalyses of presolar grains provide direct information on the physical and chemical properties of solid condensates that form in the mass outflows from stars. This informa- tion can be used, in conjunction with kinetic models and equilibrium thermodynamics, to draw inferences about condensation sequences, formation intervals, pressures, and temperatures in circumstellar envelopes and in supernova ejecta. We review the results of detailed microana- lytical studies of the presolar graphite, presolar silicon carbide, and nanodiamonds found in primitive meteorites. We illustrate how these investigations, together with astronomical obser- vation and theoretical models, provide detailed information on grain formation and growth that could not be obtained by astronomical observation alone. 1. INTRODUCTION versed the interstellar medium (ISM) prior to their incorpor- ation into the solar nebula, they serve as monitors of physi- In recent years the laboratory study of presolar grains has cal and chemical processing of grains in the ISM (Bernato- emerged as a rich source of astronomical information about wicz et al., 2003). stardust, as well as about the physical and chemical condi- In this review we focus on carbonaceous presolar grains. tions of dust formation in circumstellar -
Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis Of
The Astrophysical Journal, 889:3 (26pp), 2020 January 20 https://doi.org/10.3847/1538-4357/ab616c © 2020. The American Astronomical Society. All rights reserved. Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Acetylene (C2H2) and D2-acetylene (C2D2) Ices Exposed to Ionizing Radiation via Ultraviolet–Visible Spectroscopy, Infrared Spectroscopy, and Reflectron Time-of-flight Mass Spectrometry Matthew J. Abplanalp1,2 and Ralf I. Kaiser1,2 1 W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA 2 Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA Received 2019 October 4; revised 2019 December 7; accepted 2019 December 10; published 2020 January 20 Abstract The processing of the simple hydrocarbon ice, acetylene (C2H2/C2D2), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles penetrating solid matter, was carried out in an ultrahigh vacuum surface apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible spectroscopy and, during temperature programmed desorption, via a quadrupole mass spectrometer with an electron impact ionization source (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing single-photon photoionization (SPI-ReTOF-MS) along with resonance-enhanced multiphoton photoionization (REMPI-ReTOF-MS). The confirmation of previous in situ studies of ethylene ice irradiation -
Origins of Life: Transition from Geochemistry to Biogeochemistry
December 2016 Volume 12, Number 6 ISSN 1811-5209 Origins of Life: Transition from Geochemistry to Biogeochemistry NITA SAHAI and HUSSEIN KADDOUR, Guest Editors Transition from Geochemistry to Biogeochemistry Staging Life: Warm Seltzer Ocean Incubating Life: Prebiotic Sources Foundation Stones to Life Prebiotic Metal-Organic Catalysts Protometabolism and Early Protocells pub_elements_oct16_1300&icpms_Mise en page 1 13-Sep-16 3:39 PM Page 1 Reproducibility High Resolution igh spatial H Resolution High mass The New Generation Ion Microprobe for Path-breaking Advances in Geoscience U-Pb dating in 91500 zircon, RF-plasma O- source Addressing the growing demand for small scale, high resolution, in situ isotopic measurements at high precision and productivity, CAMECA introduces the IMS 1300-HR³, successor of the internationally acclaimed IMS 1280-HR, and KLEORA which is derived from the IMS 1300-HR³ and is fully optimized for advanced U-Th-Pb mineral dating. • New high brightness RF-plasma ion source greatly improving spatial resolution, reproducibility and throughput • New automated sample loading system with motorized sample height adjustment, significantly increasing analysis precision, ease-of-use and productivity • New UV-light microscope for enhanced optical image resolution (developed by University of Wisconsin, USA) ... and more! Visit www.cameca.com or email [email protected] to request IMS 1300-HR³ and KLEORA product brochures. Laser-Ablation ICP-MS ~ now with CAMECA ~ The Attom ES provides speed and sensitivity optimized for the most demanding LA-ICP-MS applications. Corr. Pb 207-206 - U (238) Recent advances in laser ablation technology have improved signal 2SE error per sample - Pb (206) Combined samples 0.076121 +/- 0.002345 - Pb (207) to background ratios and washout times. -
Basic Keyword List
NOTICE TO AUTHORS 2008 Basic Keyword list A Antibodies Bismuth Chalcogens Ab initio calculations Antifungal agents Block copolymers Chaperone proteins Absorption Antigens Bond energy Charge carrier injection Acidity Antimony Bond theory Charge transfer Actinides Antisense agents Boranes Chelates Acylation Antitumor agents Borates Chemical vapor deposition Addition to alkenes Antiviral agents Boron Chemical vapor transport Addition to carbonyl com- Aqueous-phase catalysis Bridging ligands Chemisorption pounds Arene ligands Bromine Chemoenzymatic synthesis Adsorption Arenes Brønsted acids Chemoselectivity Aerobic oxidation Argon Chiral auxiliaries Aggregation Aromatic substitution C Chiral pool Agostic interactions Aromaticity C-C activation Chiral resolution Alanes Arsenic C-C bond formation Chirality Alcohols Arylation C-C coupling Chlorine Aldehydes Aryl halides C-Cl bond activation Chromates Aldol reaction Arynes C-Glycosides Chromium Alkali metals As ligands C-H activation Chromophores Alkaline earth metals Asymmetric amplification C1 building blocks Circular dichroism Alkaloids Asymmetric catalysis Cadmium Clathrates Alkanes Asymmetric synthesis Cage compounds Clays Alkene ligands Atmospheric chemistry Calcium Cleavage reactions Alkenes Atom economy Calixarenes Cluster compounds Alkylation Atropisomerism Calorimetry Cobalamines Alkyne ligands Aurophilicity Carbanions Cobalt Alkynes Autocatalysis Carbene homologues Cofactors Alkynylation Automerization Carbene ligands Colloids Allenes Autoxidation Carbenes Combinatorial chemistry Allosterism -
Photochemistry of Highly Excited States R
COMMENTARY COMMENTARY Photochemistry of highly excited states R. D. Levinea,b,c,1 These days on earth we are photochemically reasonably A forceful illustration of the benefits of the synergy of well shielded. The far UV radiation is filtered by the ozone experiment and theory in understanding the detailed and other components of the atmosphere. In the iono- electronic and nuclear dynamics in highly excited states is sphere and beyond there is much challenging chemistry provided by the very recent work reported by Peters et al. induced by such higher-energy photons. The shielding by (8). Methyl azide is pumped by an 8-eV vacuum UV (VUV) the atmosphere also makes demands on such experi- pulse of 10-fs duration and probed by a second 1.6-eV in- ments in the laboratory. There is, however, recent interest frared (IR) pulse that ionizes the molecule. The experiment largely driven by technology that makes higher resolution as seen through the eyes of a theorist is shown in Fig. 1. The possible. The experimental technology is advanced light pump pulse prepares a single excited electronic state, la- sources that offer far higher intensities, sharper wave- beled as S8, that theory shows has a mixed valence and length definition or, complementarily, short-duration Rydberg character. It is unusual that a single excited state pulses. The two alternatives make a whole because of is accessed at such a high energy. The high-level computa- the quantum mechanical time–energy uncertainty princi- tions reported by Peters et al. are quite clear that the ple that makes short pulses necessarily broad in energy. -
Lifetimes of Interstellar Dust from Cosmic Ray Exposure Ages of Presolar Silicon Carbide
Lifetimes of interstellar dust from cosmic ray exposure ages of presolar silicon carbide Philipp R. Hecka,b,c,1, Jennika Greera,b,c, Levke Kööpa,b,c, Reto Trappitschd, Frank Gyngarde,f, Henner Busemanng, Colin Madeng, Janaína N. Ávilah, Andrew M. Davisa,b,c,i, and Rainer Wielerg aRobert A. Pritzker Center for Meteoritics and Polar Studies, The Field Museum of Natural History, Chicago, IL 60605; bChicago Center for Cosmochemistry, The University of Chicago, Chicago, IL 60637; cDepartment of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637; dNuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550; ePhysics Department, Washington University, St. Louis, MO 63130; fCenter for NanoImaging, Harvard Medical School, Cambridge, MA 02139; gInstitute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland; hResearch School of Earth Sciences, The Australian National University, Canberra, ACT 2601, Australia; and iEnrico Fermi Institute, The University of Chicago, Chicago, IL 60637 Edited by Mark H. Thiemens, University of California San Diego, La Jolla, CA, and approved December 17, 2019 (received for review March 15, 2019) We determined interstellar cosmic ray exposure ages of 40 large ago. These grains are identified as presolar by their large isotopic presolar silicon carbide grains extracted from the Murchison CM2 anomalies that exclude an origin in the Solar System (13, 14). meteorite. Our ages, based on cosmogenic Ne-21, range from 3.9 ± Presolar stardust grains are the oldest known solid samples 1.6 Ma to ∼3 ± 2 Ga before the start of the Solar System ∼4.6 Ga available for study in the laboratory, represent the small fraction ago. -
Interstellar Dust Within the Life Cycle of the Interstellar Medium K
EPJ Web of Conferences 18, 03001 (2011) DOI: 10.1051/epjconf/20111803001 C Owned by the authors, published by EDP Sciences, 2011 Interstellar dust within the life cycle of the interstellar medium K. Demyk1,2,a 1Université de Toulouse, UPS-OMP, IRAP, Toulouse, France 2CNRS, IRAP, 9 Av. colonel Roche, BP. 44346, 31028 Toulouse Cedex 4, France Abstract. Cosmic dust is omnipresent in the Universe. Its presence influences the evolution of the astronomical objects which in turn modify its physical and chemical properties. The nature of cosmic dust, its intimate coupling with its environment, constitute a rich field of research based on observations, modelling and experimental work. This review presents the observations of the different components of interstellar dust and discusses their evolution during the life cycle of the interstellar medium. 1. INTRODUCTION Interstellar dust grains are found everywhere in the Universe: in the Solar System, around stars at all evolutionary stages, in interstellar clouds of all kind, in galaxies and in the intergalactic medium. Cosmic dust is intimately mixed with the gas-phase and represents about 1% of the gas (in mass) in our Galaxy. The interstellar extinction and the emission of diffuse interstellar clouds is reproduced by three dust components: a population of large grains, the BGs (Big Grains, ∼10–500 nm) made of silicate and a refractory mantle, a population of carbonaceous nanograins, the VSGs (Very Small Grains, 1–10 nm) and a population of macro-molecules the PAHs (Polycyclic Aromatic Hydrocarbons) [1]. These three components are more or less abundant in the diverse astrophysical environments reflecting the coupling of dust with the environment and its evolution according to the physical and dynamical conditions. -
Appendix A: Scientific Notation
Appendix A: Scientific Notation Since in astronomy we often have to deal with large numbers, writing a lot of zeros is not only cumbersome, but also inefficient and difficult to count. Scientists use the system of scientific notation, where the number of zeros is short handed to a superscript. For example, 10 has one zero and is written as 101 in scientific notation. Similarly, 100 is 102, 100 is 103. So we have: 103 equals a thousand, 106 equals a million, 109 is called a billion (U.S. usage), and 1012 a trillion. Now the U.S. federal government budget is in the trillions of dollars, ordinary people really cannot grasp the magnitude of the number. In the metric system, the prefix kilo- stands for 1,000, e.g., a kilogram. For a million, the prefix mega- is used, e.g. megaton (1,000,000 or 106 ton). A billion hertz (a unit of frequency) is gigahertz, although I have not heard of the use of a giga-meter. More rarely still is the use of tera (1012). For small numbers, the practice is similar. 0.1 is 10À1, 0.01 is 10À2, and 0.001 is 10À3. The prefix of milli- refers to 10À3, e.g. as in millimeter, whereas a micro- second is 10À6 ¼ 0.000001 s. It is now trendy to talk about nano-technology, which refers to solid-state device with sizes on the scale of 10À9 m, or about 10 times the size of an atom. With this kind of shorthand convenience, one can really go overboard.