DOCSLIB.ORG

Scientific Promise and Opportunities

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Giant Magellan Telescope Scientific Promise and Opportunities 2012 Table of Contents 1 INTRODUCTION ............................................................................................................................ 1 1.1 PURPOSE AND SCOPE OF THE DOCUMENT .................................................................................................. 1 1.2 OVERVIEW OF THE GIANT MAGELLAN TELESCOPE PROJECT ........................................................................... 1 1.3 STRUCTURE OF THE GMT SCIENCE CASE .................................................................................................... 3 1.4 DISCOVERY SPACE OPENED BY THE GMT ................................................................................................... 4 1.5 CONTEMPORARY SCIENCE GOALS ............................................................................................................. 6 1.6 SCIENTIFIC SYNERGIES ............................................................................................................................ 7 1.7 GMT INSTRUMENT CANDIDATES ............................................................................................................. 7 1.8 ADAPTIVE OPTICS SYSTEM ...................................................................................................................... 9 1.9 SUMMARY ......................................................................................................................................... 10 1.10 LIST OF CONTRIBUTORS ........................................................................................................................ 11 2 FORMATION OF STARS AND PLANETARY SYSTEMS...................................................................... 12 2.1 INTRODUCTION ................................................................................................................................... 12 2.1.1 Synergy with other instruments ............................................................................................ 13 2.2 ASTROPHYSICS OF YOUNG STARS ............................................................................................................ 13 2.3 THE INITIAL MASS FUNCTION AND THE POTENTIAL FOR PLANETS .................................................................. 16 2.4 HOW CIRCUMSTELLAR DISKS FORM PLANETS ........................................................................................... 17 2.5 VOLATILE DELIVERY AND PLANETARY SYSTEM ARCHITECTURE ...................................................................... 20 2.6 SOLAR SYSTEM CLUES TO PLANET FORMATION ......................................................................................... 22 2.7 SUMMARY ......................................................................................................................................... 23 REFERENCES ................................................................................................................................................ 24 3 THE PROPERTIES OF EXOPLANETARY SYSTEMS ........................................................................... 25 3.1 INTRODUCTION ................................................................................................................................... 25 3.1.1 Current models of Planet Formation .................................................................................... 26 3.2 PROBING EXOPLANET ATMOSPHERES ...................................................................................................... 27 3.3 IMAGING EXOPLANETARY SYSTEMS ......................................................................................................... 28 3.3.1 Young Gas‐Giant Planets ...................................................................................................... 30 3.3.2 Spectroscopy in the Near‐Infrared ........................................................................................ 31 3.3.3 Thermal Imaging of Older and Smaller Planets .................................................................... 31 3.4 PROBING THE NEAREST HABITABLE PLANETS USING DOPPLER SPECTROSCOPY ................................................ 33 3.4.1 Earth‐analogues Orbiting Sun‐type Stars ............................................................................. 33 3.4.2 Habitable planets orbiting M‐dwarf Stars ............................................................................ 35 3.5 SUMMARY ......................................................................................................................................... 36 REFERENCES ................................................................................................................................................ 37 4 STELLAR POPULATIONS AND CHEMICAL EVOLUTION ................................................................... 38 4.1 INTRODUCTION ................................................................................................................................... 38 4.2 STELLAR ARCHAEOLOGY ....................................................................................................................... 40 4.2.1 Characterizing the Most Metal‐poor Stars ........................................................................... 40 4.2.2 Age Dating the Oldest Stars .................................................................................................. 42 4.3 ABUNDANCES IN DWARF GALAXY STARS .................................................................................................. 43 4.4 PROBING THE ORIGIN OF THE MILKY WAY’S HALO .................................................................................... 45 4.5 GLOBULAR CLUSTERS IN LOCAL GROUP GALAXIES AND BEYOND ................................................................... 46 4.6 STAR FORMATION IN THE MILKY WAY'S 5KPC RING ................................................................................... 47 4.7 SUMMARY ......................................................................................................................................... 49 REFERENCES ................................................................................................................................................ 49 5 GALAXY ASSEMBLY AND EVOLUTION .......................................................................................... 50 5.1 INTRODUCTION ................................................................................................................................... 50 5.2 NEAR‐FIELD STUDIES OF GALAXY ASSEMBLY ............................................................................................. 50 5.3 THE GALAXY BUILDING EPOCH ............................................................................................................... 52 5.3.1 Star Formation, Mass Assembly and Chemical Evolution ..................................................... 52 5.3.2 Dynamical Masses ................................................................................................................ 53 5.3.3 Kinematics of Star Forming Galaxies .................................................................................... 55 5.3.4 The Mass‐Metallicity Relation .............................................................................................. 57 5.4 FEEDBACK AND THE GALAXY‐IGM CONNECTION ........................................................................................ 58 5.5 THE GALAXY‐BLACK HOLE CONNECTION .................................................................................................. 61 5.6 SUMMARY ......................................................................................................................................... 64 REFERENCES ................................................................................................................................................ 64 6 DARK MATTER, DARK ENERGY AND FUNDAMENTAL PHYSICS ..................................................... 66 6.1 INTRODUCTION ................................................................................................................................... 66 6.2 SYNERGY WITH LSST ........................................................................................................................... 68 6.3 CLUSTERS AND DARK MATTER ............................................................................................................... 70 6.4 DARK MATTER PROFILES IN DWARF GALAXIES .......................................................................................... 73 6.5 SUMMARY ......................................................................................................................................... 75 REFERENCES ................................................................................................................................................ 75 7 FIRST LIGHT AND REIONIZATION ................................................................................................. 77 7.1 INTRODUCTION ................................................................................................................................... 77 7.2 THE FIRST DARK MATTER HALOS, STARS AND GALAXIES ............................................................................. 77 7.3 GALAXIES IN THE EARLY UNIVERSE .......................................................................................................... 79 7.4 DISCOVERING THE FIRST STARS
Recommended publications
  • Publications for Dr. Peter L. Capak 1 of 21 Publication Summary 369

    Publications for Dr. Peter L. Capak 1 of 21 Publication Summary 369

    Publications for Dr. Peter L. Capak Publication Summary 369 Publications 319 Refereed Publications Accepted or Submitted 50 Un-refereed Publications Top 1% of Cited Researchers in 2017-2019 >30,000 Citations >1,600 Citations on first author papers 99 papers with >100 citations, 6 as first author. H Index = 99 First Author publications 1) Capak et al., 2015, “Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission”, Nature, 522, 455 2) Capak et al., 2013, “Keck-I MOSFIRE Spectroscopy of the z ~ 12 Candidate Galaxy UDFj-39546284”, ApJL, 733, 14 3) Capak et al., 2011, “A massive protocluster of galaxies at a redshift of z~5.3” , Nature, 470, 233 4) Capak et al., 2010, “Spectroscopy and Imaging of three bright z>7 candidates in the COSMOS survey”, ApJ, 730, 68 5) Capak et al., 2008, "Spectroscopic Confirmation Of An Extreme Starburst At Redshift 4.547", ApJL, 681, 53 6) Capak et. al., 2007, "The effects of environment on morphological evolution between 0<z<1.2 in the COSMOS Survey", ApJS, 172, 284 7) Capak et. al., 2007, "The First Release COSMOS Optical and Near-IR Data and Catalog", ApJS, 172, 99 8) Capak, 2004, “Probing global star and galaxy formation using deep multi-wavelength surveys”, Ph.D. Thesis 9) Capak et. al., 2004, "A Deep Wide-Field, Optical, and Near-Infrared Catalog of a Large Area around the Hubble Deep Field North", AJ, 127, 180 Other Publications (P. Capak was a leading author in bolded entries) 10) Faisst et al., 2020, “The ALPINE-ALMA [CII] survey: Multi-Wavelength Ancillary Data.
  • Overview and Status of the Giant Magellan Telescope Project

    Overview and Status of the Giant Magellan Telescope Project

    Invited Paper Overview and Status of the Giant Magellan Telescope Project Patrick J. McCarthy*,a,b, James Fansona, Rebecca Bernsteina,b, David Ashbyc, Bruce Bigelowa, Nune Boyadjiana, Antonin Boucheza, Eric Chauvina, Eduardo Donosoa, Jose Filgueiraa, Robert Goodricha, Frank Groarka, George Jacobya, Eric Pearcea aGMTO Corporation, 451 N. Halstead St., Suite 250, Pasadena, CA 91107, USA bCarnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101, USA cLarge Binocular Telescope Observatory, Tucson AZ ABSTRACT The Giant Magellan Telescope Project is in the construction phase. Production of the primary mirror segments is underway with four of the seven required 8.4m mirrors at various stages of completion and materials purchased for segments five and six. Development of the infrastructure at the GMT site at Las Campanas is nearing completion. Power, water and data connections sufficient to support the construction of the telescope and enclosure are in place and roads to the summit have been widened and graded to support transportation of large and heavy loads. Construction pads for the support buildings have been graded and the construction residence is being installed. A small number of issues need to be resolved before the final design of the telescope structure and enclosure can proceed and the GMT team is collecting the required inputs to the decision making process. Prototyping activities targeted at the active and adaptive optics systems are allowing us to finalize designs before large scale production of components begins. Our technically driven schedule calls for the telescope to be assembled on site in 2022 and to be ready to receive a subset of the primary and secondary mirror optics late in the year.
  • The Large–Scale Distribution of Galaxies in the Shapley Concentration

    The Large–Scale Distribution of Galaxies in the Shapley Concentration

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server The large{scale distribution of galaxies in the Shapley Concentration S. Bardelli Osservatorio Astronomico di Trieste, via Tiepolo 11, I{34131 Trieste, Italy E. Zucca, G. Zamorani Osservatorio Astronomico di Bologna, via Zamboni 33, I{40126 Bologna, Italy Abstract. We present the results of a galaxy redshift survey in the central region of the Shapley Concentration. Our total sample contains 2000 radial velocities of galaxies both in the clusters and in the inter- cluster∼ field. We reconstruct the density profile of this supercluster, cal- culate its overdensity and total mass. Moreover we detect a massive structure behind the Shapley Concentration, at 30000 km/s. ∼ 1. Introduction The Shapley Concentration stands out as the richest system of Abell clusters in the list of Zucca et al. (1993), at every density excess. In particular, at a density contrast of 2, it has 25 members (at mean velocity 14000 km/s), while at the same density∼ contrast the Great Attractor, which is∼ the largest mass 1 condensation within 80 h− Mpc, has only 6 members and the Corona Borealis and Hercules superclusters are formed by 10 and 8 clusters, respectively. While the cluster distribution in the Shapley Concentration has been well studied, little is known about the distribution of the galaxies. Determining the properties of these galaxies is very important in order to assess the physical reality and extension of the structure and to determine if galaxies and clusters trace the matter distribution in the same way.
  • Where Are the Distant Worlds? Star Maps

    Where Are the Distant Worlds? Star Maps

    W here Are the Distant Worlds? Star Maps Abo ut the Activity Whe re are the distant worlds in the night sky? Use a star map to find constellations and to identify stars with extrasolar planets. (Northern Hemisphere only, naked eye) Topics Covered • How to find Constellations • Where we have found planets around other stars Participants Adults, teens, families with children 8 years and up If a school/youth group, 10 years and older 1 to 4 participants per map Materials Needed Location and Timing • Current month's Star Map for the Use this activity at a star party on a public (included) dark, clear night. Timing depends only • At least one set Planetary on how long you want to observe. Postcards with Key (included) • A small (red) flashlight • (Optional) Print list of Visible Stars with Planets (included) Included in This Packet Page Detailed Activity Description 2 Helpful Hints 4 Background Information 5 Planetary Postcards 7 Key Planetary Postcards 9 Star Maps 20 Visible Stars With Planets 33 © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Detailed Activity Description Leader’s Role Participants’ Roles (Anticipated) Introduction: To Ask: Who has heard that scientists have found planets around stars other than our own Sun? How many of these stars might you think have been found? Anyone ever see a star that has planets around it? (our own Sun, some may know of other stars) We can’t see the planets around other stars, but we can see the star.
  • Homogeneous Spectroscopic Parameters for Bright Planet Host Stars from the Northern Hemisphere the Impact on Stellar and Planetary Mass (Research Note)

    Homogeneous Spectroscopic Parameters for Bright Planet Host Stars from the Northern Hemisphere the Impact on Stellar and Planetary Mass (Research Note)

    A&A 576, A94 (2015) Astronomy DOI: 10.1051/0004-6361/201425227 & c ESO 2015 Astrophysics Homogeneous spectroscopic parameters for bright planet host stars from the northern hemisphere The impact on stellar and planetary mass (Research Note) S. G. Sousa1,2,N.C.Santos1,2, A. Mortier1,3,M.Tsantaki1,2, V. Adibekyan1, E. Delgado Mena1,G.Israelian4,5, B. Rojas-Ayala1,andV.Neves6 1 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal 3 SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK 4 Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain 5 Departamento de Astrofísica, Universidade de La Laguna, 38205 La Laguna, Tenerife, Spain 6 Departamento de Física, Universidade Federal do Rio Grande do Norte, Brazil Received 27 October 2014 / Accepted 19 February 2015 ABSTRACT Aims. In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods. To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius.
  • Arxiv:1305.7264V2 [Astro-Ph.EP] 21 Apr 2014 Spain

    Arxiv:1305.7264V2 [Astro-Ph.EP] 21 Apr 2014 Spain

    Draft version September 18, 2018 Preprint typeset using LATEX style emulateapj v. 08/22/09 THE MOVING GROUP TARGETS OF THE SEEDS HIGH-CONTRAST IMAGING SURVEY OF EXOPLANETS AND DISKS: RESULTS AND OBSERVATIONS FROM THE FIRST THREE YEARS Timothy D. Brandt1, Masayuki Kuzuhara2, Michael W. McElwain3, Joshua E. Schlieder4, John P. Wisniewski5, Edwin L. Turner1,6, J. Carson7,4, T. Matsuo8, B. Biller4, M. Bonnefoy4, C. Dressing9, M. Janson1, G. R. Knapp1, A. Moro-Mart´ın10, C. Thalmann11, T. Kudo12, N. Kusakabe13, J. Hashimoto13,5, L. Abe14, W. Brandner4, T. Currie15, S. Egner12, M. Feldt4, T. Golota12, M. Goto16, C. A. Grady3,17, O. Guyon12, Y. Hayano12, M. Hayashi18, S. Hayashi12, T. Henning4, K. W. Hodapp19, M. Ishii12, M. Iye13, R. Kandori13, J. Kwon13,22, K. Mede18, S. Miyama20, J.-I. Morino13, T. Nishimura12, T.-S. Pyo12, E. Serabyn21, T. Suenaga22, H. Suto13, R. Suzuki13, M. Takami23, Y. Takahashi18, N. Takato12, H. Terada12, D. Tomono12, M. Watanabe24, T. Yamada25, H. Takami12, T. Usuda12, M. Tamura13,18 Draft version September 18, 2018 ABSTRACT We present results from the first three years of observations of moving group targets in the SEEDS high-contrast imaging survey of exoplanets and disks using the Subaru telescope. We achieve typical contrasts of ∼105 at 100 and ∼106 beyond 200 around 63 proposed members of nearby kinematic moving groups. We review each of the kinematic associations to which our targets belong, concluding that five, β Pictoris (∼20 Myr), AB Doradus (∼100 Myr), Columba (∼30 Myr), Tucana-Horogium (∼30 Myr), and TW Hydrae (∼10 Myr), are sufficiently well-defined to constrain the ages of individual targets.
  • Li Abundances in F Stars: Planets, Rotation, and Galactic Evolution�,

    Li Abundances in F Stars: Planets, Rotation, and Galactic Evolution,

    A&A 576, A69 (2015) Astronomy DOI: 10.1051/0004-6361/201425433 & c ESO 2015 Astrophysics Li abundances in F stars: planets, rotation, and Galactic evolution, E. Delgado Mena1,2, S. Bertrán de Lis3,4, V. Zh. Adibekyan1,2,S.G.Sousa1,2,P.Figueira1,2, A. Mortier6, J. I. González Hernández3,4,M.Tsantaki1,2,3, G. Israelian3,4, and N. C. Santos1,2,5 1 Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal 3 Instituto de Astrofísica de Canarias, C/via Lactea, s/n, 38200 La Laguna, Tenerife, Spain 4 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain 5 Departamento de Física e Astronomía, Faculdade de Ciências, Universidade do Porto, Portugal 6 SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, UK Received 28 November 2014 / Accepted 14 December 2014 ABSTRACT Aims. We aim, on the one hand, to study the possible differences of Li abundances between planet hosts and stars without detected planets at effective temperatures hotter than the Sun, and on the other hand, to explore the Li dip and the evolution of Li at high metallicities. Methods. We present lithium abundances for 353 main sequence stars with and without planets in the Teff range 5900–7200 K. We observed 265 stars of our sample with HARPS spectrograph during different planets search programs. We observed the remaining targets with a variety of high-resolution spectrographs.
  • Nested Sampling

    Nested Sampling

    Probabilistic Source Detection Farhan Feroz [email protected] Cavendish Astrophysics Source/Object Detection: Problem Definition • Aim: Detect and characterize discrete sources in a background • Each source described by a template f(p) with parameters p. • With source and noise contributions being additive and Ns source Ns d=++ bq() nr ()∑ f ( pk ) k =1 • Inference goal: Use data d to constrain source parameters Ns, pk (k = 1, 2, …, Ns). Margnialize over background and noise parameters (q and r). Probabilistic Source/Object Detection • Problems in Object Detection – Identification – Quantifying Detection – Characterization Textures in CMB Bayesian Parameter Estimation • Collect a set of N data points Di (i = 1, 2, …, N), denoted collectively as data vector D. • Propose some model (or hypothesis) H for the data, depending on a set of M parameter θi (i = 1, 2, …, N), denoted collectively as parameter vector θ. • Bayes’ Theorem: Likelihood Prior P(D | θ, H )P(θ | H ) L(θ)π(θ) P(θ | D, H ) = → P(θ) = P(D | H) Z Posterior Evidence • Parameter Estimation: P(θ) α L(θ)π(θ) posterior α likelihood x prior Bayesian Model Selection P(D | θ, H )P(θ | H ) P(D | H )P(H ) P(θ | D, H ) = → P(H | D) = P(D | H) P(D) Bayes Factor • Consider two models H0 and H1 Prior P(H | D) P(D | H )P(H ) Z P(H ) Odds R = 1 = 1 1 = 1 1 P(H 0 | D) P(D | H 0 )P(H 0 ) Z0 P(H 0 ) • Bayesian Evidence Z = P(D|H) = ∫ L ( θ ) π ( θ ) d θ plays the central role in Bayesian Model Selection.
  • Naming the Extrasolar Planets

    Naming the Extrasolar Planets

    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
  • Cr&gt; Γ- ΟΟ [ Publications of the Astronomical Society of the Pacific

    Cr> Γ- ΟΟ [ Publications of the Astronomical Society of the Pacific

    cr> - ΟΟΓ [ Publications of the Astronomical Society of the Pacific cs] 102:379-411, April 1990 \—I0 ωCu 1 PUBLICATIONS OF THE 2 ASTRONOMICAL SOCIETY OF THE PACIFIC Vol. 102 April 1990 No. 650 CONTEMPORARY OPTICAL SPECTRAL CLASSIFICATION OF THE OB STARS: A DIGITAL ATLAS* NOLAN R. WALBORNt Space Telescope Science Institute, φ 3700 San Martin Drive, Baltimore, Maryland 21218 AND EDWARD L. FITZPATRICKf Princeton University Observatory, Peyton Hall, Princeton, New Jersey 08544 Received 1990 ABSTRACT Some recent developments in the optical classification of OB spectra are reviewed in terms of a comprehensive atlas of new blue-violet digital data from the CTIO 1-meter photon-counting system. These developments include the OS spectral type; luminosity criteria for the O stars; OBN/OBC anomalies; and refined, interpolated late-O/early-B types. Examples of these phenom- ena are included among extensive spectral- and luminosity-class sequences, comprising 75 standard objects arranged into 27 montages and covering the wavelength range 3950 Â-4750 A for types OS-BS (-B8 at Iö). It is intended that this atlas serve a reference function analogous to that of the printed MK atlases, for morphological investigations of OB spectra based on digital data, which will supersede photographic techniques in most future applications. Key words: spectral atlas-OB stars 1. Introduction and Background The Μ Κ classification was based on blue-violet The system of spectral classification provided one (3900 Â-4900 A) photographic spectrograms of disper- Μ Κ -1 of the foundations of stellar astrophysics. Far from being sion ~ 100 A mm (resolution ~ 2 A) and widening at rendered obsolete by the development of the latter, how- least 0.5 mm.
  • Experimental Facilities in Latin America

    Experimental Facilities in Latin America

    CLASHEP 2019, Villa General Belgrano, Córdoba, Argentina Experimental Facilities in Latin America Claudio O. Dib Universidad Técnica Federico Santa María, Valparaíso, Chile 7 to 5 Content: • Brief introduction to Particle Physics experiments. • Accelerator Facilities in L.A. • Astronomical Observatories in L.A. (current and future) - VLT, ALMA, DSA3, DES, LSST, GMT, ELT, LLAMA. • Current Astroparticle Facilities in L.A. - Auger - Parenthesis on Cosmic Rays and Extensive Air Showers. - LAGO, HAWC • Future Astroparticle Facilities in L.A. - CTA, ALPACA, LATTES, SGSO, ANDES • Summary 6 to 5 Particle Physics experiments: - Table top experiments E. Rutherford’s lab., Cambridge U. - Cosmic ray detection (Astroparticle Physics) - Accelerators and colliders: (cyclotrons, synchrotrons, linacs; fixed target collisions, colliding beams) 5 to 5 Past table-top experiments 1895: J.J Thomson -> electron J.J. Thomson. Credit: Cambridge U., Cavendish Lab. 1911: E. Rutherford -> nucleus & proton 1932: J. Chadwick -> neutron 4 to 5 J.A. Ratcliffe & E. Rutherford, Cavendish Lab. Cosmic ray experiments • Cosmic rays: radiation that comes from outer space. • Discovered in 1912 by Victor Hess: – Went up a Balloon up to 5300 m: Radiation is higher further above. • Named cosmic rays by R. A. Millikan. Victor F. Hess preparing the baloon flight Cosmic rays are actually… particles! (mainly protons & heavier nuclei) 3 to 5 Robert A. Millikan. Caltech archives. Cosmic ray experiments 1932: C. Anderson discovers the positron. 1947: C. Powell, G. Occhialini, C. Lattes
  • Dynamical Stability and Habitability of a Terrestrial Planet in HD74156

    Dynamical Stability and Habitability of a Terrestrial Planet in HD74156

    A dynamic search for potential habitable planets amongst the extrasolar planets 1,2 1 1 1,3 1, 4 P. Hinds , A. Munro , S. T. Maddison , C. Tan , and M. C. Gino [1] Swinburne University, Australia [2] Pierce College, USA [3] Methodist Ladies’ College, Australia [4] Dudley Observatory, USA ABSTRACT: While the detection of habitable terrestrial planets around nearby stars is currently beyond our observational capabilities, dynamical studies can help us locate potential candidates. Following from the work of Menou & Tabachnik (2003), we use a symplectic integrator to search for potential stable terrestrial planetary orbits in the habitable zones of known extrasolar planetary systems. A swarm of massless test particles is initially used to identify stability zones, and then an Earth-mass planet is placed within these zones to investigate their dynamical stability. We investigate 22 new systems discovered since the work of Menou & Tabachnik, as well as simulate some of the previous 85 extrasolar systems whose orbital parameters have been more precisely constrained. In particular, we model three systems that are now confirmed or potential double planetary systems: HD169830, HD160691 and eps Eridani. The results of these dynamical studies can be used as a potential target list for the Terrestrial Planet Finder. Introduction Numerical Technique Results & Discussion To date 122 extrasolar planets have been detected around 107 stars, with 13 of them To follow the evolution of the planetary systems, we use the SWIFT integration software package1. This The systems we have investigated broadly fall in four categories: (1) unstable being multiple planet systems (Schneider, 2004). Observational evidence for the allows us to model a planetary system and a swarm of massless test particles in orbit around a central star.