DOCSLIB.ORG

Publications OFTHE Astronomical Society OFTHE Pacific 100:1071-1075, September 1988

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Publications OFTHE Astronomical Society OFTHE Pacific 100:1071-1075, September 1988 Publications OFTHE Astronomical Society OFTHE Pacific 100:1071-1075, September 1988 SUPPLEMENTAL TOPICS ON VOIDS HERBERT]. ROOD P.O. Box 1330, Princeton, New Jersey 08542 Received 1988 April 9, revised 1988 May 16 ABSTRACT 1. In the spring of 1975 on Kitt Peak, the cosmological significance of superclusters and voids was clearly recognized by the small group of astronomers who were completing redshift surveys that first demonstrated the existence of the Coma supercluster and void. 2. A redshift survey to a faint magnitude limit over a large region of the sky can include, e.g., (a) all galaxies, (b) the galaxies in representative probes, or (c) randomly-sampled galaxies. Each of these map-making strategies has its own special virtues. 3. Redshifts for the Abell clusters and very distant objects are being measured from spectra of (a) individual galaxies recorded electronically and (b) several galaxies recorded simultaneously by means of (1) multiobject spectroscopy via multiaperture or fiber-optic coupling devices, (2) analysis of features on objective-prism spectral plates of Schmidt telescopes, and (3) computer synthesiza- tion of spectra from observed multicolor CCD images of a field. 4. A beautiful consistency now exists between the observed kinematics of the solar system and the predictions of Newtonian/general relativistic dynamics. However, a century ago serious dis- crepancies existed, and explanations were sought in terms of hypothesized missing mass and non-Newtonian dynamics. Today, the same approach is being applied toward resolving discrepan- cies apparent in extragalactic dynamics. 5. Future observational research on voids will include redshift surveys of galaxies and other objects to very faint magnitude limits. These objects will be selected from catalogs of data measured off direct-survey photographic plates by means of an automated plate scanner. Key words: galaxies-voids-superclusters I. Preface servational efforts with strong theoretical connections. For a few days in 1975 the totality of active research on An article entitled "Voids ', scheduled for publication in voids was contained within a microcosm of two simulta- Volume 26 of Annual Review of Astronomy and As- neous observing runs by these five astronomers on Kitt trophysics (Rood 1988), reviews our current knowledge of Peak in Arizona. voids in the space distribution of galaxies. The length of Section III describes various strategies to obtain exten- the submitted manuscript was estimated to be 64 printed sive surveys of redshifts of galaxies that have been applied pages, more than twice the allotted 30 pages. By re- toward enhancing our knowledge of large-scale structure moving material judged to be somewhat parenthetical to in the cosmos. This section also provides references to the overall discussion, the editors were able to trim the galaxy redshift surveys in the constellations Perseus, final text by about 20% and obtain a more tightly-focused Pisces, Ursa Major and Lynx, Hydra-Centaurus, Pisces- review. The editorially-removed material is primarily Cetus, and Corona Borealis. (Rood (1988) concentrates seven self-contained sections (five are reproduced below) exclusively on galaxy redshift surveys in Coma, Hercules, that could interest researchers on voids and mass/time- and Bootes.) Finally, the researcher is cautioned to not scale problems in extragalactic dynamics. mistake an apparent void at small Galactic latitude (likely Section II is a historical tidbit of some interest. Today to be a dust void) for a physical void in the galaxy distribu- the existence and cosmological significance of superclus- tion. ters and voids is widely recognized. In 1975 the existence Section IV describes several techniques to determine of superclusters was controversial and, so far as I have redshifts of individual and especially ensembles of very been able to determine, only five astronomers knew that faint galaxies that could play significant roles in the red- both superclusters and voids exist and that their impor- shift mapping of ever-more-distant regions of the uni- tance for cosmology would soon cause a transformation verse. from modest observational studies to very extensive ob- Section V describes (a) the beautiful consistency that 1071 © Astronomical Society of the Pacific · Provided by the NASA Astrophysics Data System 1072 HERBERT J. ROOD now exists between the observed kinematics of the solar tra and then deposits these data on magnetic tape for system and the predictions of Newtonian/general rela- computer utilization—a technique that was soon to revo- tivistic dynamics and (b) the serious problems that existed lutionize optical spectroscopy (Shectman and Hiltner a century ago in the dynamics of the solar system. The 1976). latter appear fundamentally very similar to problems that The midday discussion revealed that (a) Tifit, Gregory, exist today in extragalactic dynamics. The resolution of and Thompson, and (b) Chincarini and I were working on these mass/time-scale problems is prerequisite to a similar projects related to large-scale structure in the definitive theoretical understanding of voids. distribution of galaxies. (Tifft s entrance into this field is a Section VI provides references that discuss anticipated spinoff of his interest in properties of galaxies in a central future redshift surveys and the automated procurement region of the Coma cluster, and his discovery that the of data on galaxies and other objects from direct photo- initial plot of redshift vs. nuclear magnitude for these graphic plates. galaxies exhibits an unexpected band-like structure (Tifft The sections herein are supplements to sections in the 1972). Because (1) the statistical significance of this and review article by Rood (1988) according to the following related structure (Tifft 1982) has decreased with the appli- correspondences: (11:1.3), (111:2.2.1), (IV:2.2.1), (V:4), cation of more accurate data (Rood 1982; Schneider 1987), and (VI :5). and (2) the velocity dispersion (i.e., temperature) of the moving electrons required to produce the observed ther- Π. A Hidden Paradigm mal hremsstrahlung X-ray spectrum of a cluster is com- I believe that the year 1975, more than any other, parable to the velocity dispersion of its galaxies derived by marks the epoch when a basic enlightenment occurred the Doppler interpretation of redshift (Mushotzky 1984; concerning the space distribution of galaxies and when Rood and Dickel 1979; Rood 1982), the effect is unlikely interest shifted decisively away from surface distributions to signal "dramatic changes in our concepts of large-scale and toward the direct results provided by means of homo- gravitation" (Tifft and Cocke 1987), but it may contain geneous redshift surveys. Some evidence follows. information about substructure in systems of galaxies.) Ever since I had seen N. Mayall's plot of radial velocity Chincarini and I described our work on the structure of versus angular distance from the center of the Coma the outskirts of the Coma cluster (reported by Chincarini cluster for a homogeneous sample of 50 galaxies (Mayall and Rood 1975). Gregory and Thompson described the 1960, Fig. 2; depicted by Rood 1988, Fig. 1), I had evidence suggesting to them that the Coma cluster and assumed that the apparent field of galaxies in a surface A1367 are components of a common supercluster, which distribution is the result of a superposition of discrete prompted them to submit a proposal to KPNO for observ- groups; however, I did not realize (as G. Chincarini did) ing time to obtain spectrograms to construct a homoge- that it was widely believed that groups were superim- neous sample of redshifts that would test this hypothesis. posed on a uniform field of galaxies, so I passed up an (Results of this study are described by Gregory and opportunity to be a coauthor on the 1975 paper describing Thompson (1978) and reviewed by Oort (1983).) Tifft then the observational evidence for universal segregation of related that a flash of insight recently caused him to redshifts and the absence of a uniform field (Chincarini realize that the complete apparent-magnitude-limited and Martins 1975). Much later, Focardi, Maraño, and redshift survey of galaxies in a 36-square-degree region Vettolani (1983a) reached similar realizations. centered on the Coma cluster that he and Gregory were The scene shifts to midday following a clear night in completing is inconsistent with the uniform field of galax- spring 1975 at Kitt Peak National Observatory (KPNO), ies suggested by Hubble and indicates that virtually all Arizona, a night when the three largest telescopes on the galaxies occur in groups and clusters with a large fraction mountain were all pointing in the same direction, toward of space completely devoid of galaxies. (The latter fact Tifft the constellation Coma Berenices. Photons were being believed especially interesting.) These results were soon gathered from galaxies by (a) the KPNO 2.2-m telescope published (Tifft and Gregory 1976). For the reasons de- equipped with a Carnegie image-tube spectrograph to scribed previously, the inference by Tifft that galaxies are complete Chincarini and Rood's (1975) homogeneous virtually all in groups and clusters was not new to Chin- redshift survey in a 30-sq-deg region west of the center of carini and me, but the significance of empty regions such the Coma cluster, (b) the new 2.3-m telescope of Steward as the void in front of the Coma cluster seems to have Observatory at the University of Arizona, equipped with been overlooked by all previous astronomers. Indeed, a new Carnegie image-tube spectrograph to complete virtually all previous observational and theoretical discus- Tifft and Gregory's (1976) homogeneous redshift survey sions of structure in the distribution of galaxies have in fields centered on the Coma cluster of radius 3° and 6°, focused on the groupings, without mention of the empty and (c) the 1.3-m telescope of the University of Michigan regions, neither of their significance nor of the possibility to test equipment near the final stages of development by that they, too, could be astronomical entities.
Load more

Recommended publications
  • Messier Objects
    Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun.
    [Show full text]
  • Isolated Elliptical Galaxies in the Local Universe
    A&A 588, A79 (2016) Astronomy DOI: 10.1051/0004-6361/201527844 & c ESO 2016 Astrophysics Isolated elliptical galaxies in the local Universe I. Lacerna1,2,3, H. M. Hernández-Toledo4 , V. Avila-Reese4, J. Abonza-Sane4, and A. del Olmo5 1 Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. V. Mackenna 4860, Santiago, Chile e-mail: [email protected] 2 Centro de Astro-Ingeniería, Pontificia Universidad Católica de Chile, Av. V. Mackenna 4860, Santiago, Chile 3 Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany 4 Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, 04510 México D. F., Mexico 5 Instituto de Astrofísica de Andalucía IAA – CSIC, Glorieta de la Astronomía s/n, 18008 Granada, Spain Received 26 November 2015 / Accepted 6 January 2016 ABSTRACT Context. We have studied a sample of 89 very isolated, elliptical galaxies at z < 0.08 and compared their properties with elliptical galaxies located in a high-density environment such as the Coma supercluster. Aims. Our aim is to probe the role of environment on the morphological transformation and quenching of elliptical galaxies as a function of mass. In addition, we elucidate the nature of a particular set of blue and star-forming isolated ellipticals identified here. Methods. We studied physical properties of ellipticals, such as color, specific star formation rate, galaxy size, and stellar age, as a function of stellar mass and environment based on SDSS data. We analyzed the blue and star-forming isolated ellipticals in more detail, through photometric characterization using GALFIT, and infer their star formation history using STARLIGHT.
    [Show full text]
  • The Dynamical State of the Coma Cluster with XMM-Newton?
    A&A 400, 811–821 (2003) Astronomy DOI: 10.1051/0004-6361:20021911 & c ESO 2003 Astrophysics The dynamical state of the Coma cluster with XMM-Newton? D. M. Neumann1,D.H.Lumb2,G.W.Pratt1, and U. G. Briel3 1 CEA/DSM/DAPNIA Saclay, Service d’Astrophysique, L’Orme des Merisiers, Bˆat. 709, 91191 Gif-sur-Yvette, France 2 Science Payloads Technology Division, Research and Science Support Dept., ESTEC, Postbus 299 Keplerlaan 1, 2200AG Noordwijk, The Netherlands 3 Max-Planck Institut f¨ur extraterrestrische Physik, Giessenbachstr., 85740 Garching, Germany Received 19 June 2002 / Accepted 13 December 2002 Abstract. We present in this paper a substructure and spectroimaging study of the Coma cluster of galaxies based on XMM- Newton data. XMM-Newton performed a mosaic of observations of Coma to ensure a large coverage of the cluster. We add the different pointings together and fit elliptical beta-models to the data. We subtract the cluster models from the data and look for residuals, which can be interpreted as substructure. We find several significant structures: the well-known subgroup connected to NGC 4839 in the South-West of the cluster, and another substructure located between NGC 4839 and the centre of the Coma cluster. Constructing a hardness ratio image, which can be used as a temperature map, we see that in front of this new structure the temperature is significantly increased (higher or equal 10 keV). We interpret this temperature enhancement as the result of heating as this structure falls onto the Coma cluster. We furthermore reconfirm the filament-like structure South-East of the cluster centre.
    [Show full text]
  • WASP Page 1 Hubble Eyes Aging Stars Science News, Vol. 148
    WASP Warren Astronomical Society Paper Volume 27, number 11 $1.00 for non-members November 1995 DATING THE COSMOS COMPUTER CHATTER ANNUAL HOLIDAY AWARDS Hubble eyes aging stars Larry F. Kalinowski Science News, Vol. 148, September 2,1995 submitted by Lorna Simmons Everyone knows you can't be older than your mother. But over the past year, observations with the Hubble Space Telescope and several other Comet DeVico has just passed perihelion in instruments seem to have contradicted this cardi- early October, so its beginning to fade from its maxi- nal rule. On the one hand, measurements of the mum brightness of 5.6. It was recovered in its seventy- speed at which the most distant galaxies are mov- four year orbit by independent comet observers Naka- ing from Earth suggest that the universe may be mura, Tanaka and Utsunomiya. It becomes a sixth no older than 8 billion to 12 billion years (SN: magnitude object on the night of the Macomb meeting, 10/8;94, p.232). On the other hand, astronomers October 19. Early reports say it has two tails. A morn- ing object, only, about fifteen degrees above the hori- estimate he ages of our galaxy's oldest stars at zon before twilight begins, it's easily observed as it 13 billion to 16 billion years. leaves Leo and enters the Ursa Major-Coma Berenices Now, new findings from Hubble may provide a area of the sky. However, it is quickly moving closer to step toward resolving this cosmic conundrum. the horizon and will become increasingly more difficult In viewing the globular cluster M4, the dense to observe during the rest of the month.
    [Show full text]
  • Astroph0807.3345 Ful
    Draft version July 22, 2008 A Preprint typeset using LTEX style emulateapj v. 08/13/06 THE INVISIBLES: A DETECTION ALGORITHM TO TRACE THE FAINTEST MILKY WAY SATELLITES S. M. Walsh1, B. Willman2, H. Jerjen1 Draft version July 22, 2008 ABSTRACT A specialized data mining algorithm has been developed using wide-field photometry catalogues, en- abling systematic and efficient searches for resolved, extremely low surface brightness satellite galaxies in the halo of the Milky Way (MW). Tested and calibrated with the Sloan Digital Sky Survey Data Release 6 (SDSS-DR6) we recover all fifteen MW satellites recently detected in SDSS, six known MW/Local Group dSphs in the SDSS footprint, and 19 previously known globular and open clusters. In addition, 30 point source overdensities have been found that correspond to no cataloged objects. The detection efficiencies of the algorithm have been carefully quantified by simulating more than three million model satellites embedded in star fields typical of those observed in SDSS, covering a wide range of parameters including galaxy distance, scale-length, luminosity, and Galactic latitude. We present several parameterizations of these detection limits to facilitate comparison between the observed Milky Way satellite population and predictions. We find that all known satellites would be detected with > 90% efficiency over all latitudes spanned by DR6 and that the MW satellite census within DR6 is complete to a magnitude limit of MV ≈−6.5 and a distance of 300 kpc. Assuming all existing MW satellites contain an appreciable old stellar population and have sizes and luminosities comparable to currently known companions, we predict a lower limit total of 52 Milky Way dwarf satellites within ∼ 260 kpc if they are uniformly distributed across the sky.
    [Show full text]
  • From Messier to Abell: 200 Years of Science with Galaxy Clusters
    Constructing the Universe with Clusters of Galaxies, IAP 2000 meeting, Paris (France) July 2000 Florence Durret & Daniel Gerbal eds. FROM MESSIER TO ABELL: 200 YEARS OF SCIENCE WITH GALAXY CLUSTERS Andrea BIVIANO Osservatorio Astronomico di Trieste via G.B. Tiepolo 11 – I-34131 Trieste, Italy [email protected] 1 Introduction The history of the scientific investigation of galaxy clusters starts with the XVIII century, when Charles Messier and F. Wilhelm Herschel independently produced the first catalogues of nebulæ, and noticed remarkable concentrations of nebulæ on the sky. Many astronomers of the XIX and early XX century investigated the distribution of nebulæ in order to understand their relation to the local “sidereal system”, the Milky Way. The question they were trying to answer was whether or not the nebulæ are external to our own galaxy. The answer came at the beginning of the XX century, mainly through the works of V.M. Slipher and E. Hubble (see, e.g., Smith424). The extragalactic nature of nebulæ being established, astronomers started to consider clus- ters of galaxies as physical systems. The issue of how clusters form attracted the attention of K. Lundmark287 as early as in 1927. Six years later, F. Zwicky512 first estimated the mass of a galaxy cluster, thus establishing the need for dark matter. The role of clusters as laboratories for studying the evolution of galaxies was also soon realized (notably with the collisional stripping theory of Spitzer & Baade430). In the 50’s the investigation of galaxy clusters started to cover all aspects, from the distri- bution and properties of galaxies in clusters, to the existence of sub- and super-clustering, from the origin and evolution of clusters, to their dynamical status, and the nature of dark matter (or “positive energy”, see e.g., Ambartsumian29).
    [Show full text]
  • Observational Cosmology - 30H Course 218.163.109.230 Et Al
    Observational cosmology - 30h course 218.163.109.230 et al. (2004–2014) PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Thu, 31 Oct 2013 03:42:03 UTC Contents Articles Observational cosmology 1 Observations: expansion, nucleosynthesis, CMB 5 Redshift 5 Hubble's law 19 Metric expansion of space 29 Big Bang nucleosynthesis 41 Cosmic microwave background 47 Hot big bang model 58 Friedmann equations 58 Friedmann–Lemaître–Robertson–Walker metric 62 Distance measures (cosmology) 68 Observations: up to 10 Gpc/h 71 Observable universe 71 Structure formation 82 Galaxy formation and evolution 88 Quasar 93 Active galactic nucleus 99 Galaxy filament 106 Phenomenological model: LambdaCDM + MOND 111 Lambda-CDM model 111 Inflation (cosmology) 116 Modified Newtonian dynamics 129 Towards a physical model 137 Shape of the universe 137 Inhomogeneous cosmology 143 Back-reaction 144 References Article Sources and Contributors 145 Image Sources, Licenses and Contributors 148 Article Licenses License 150 Observational cosmology 1 Observational cosmology Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors. Early observations The science of physical cosmology as it is practiced today had its subject material defined in the years following the Shapley-Curtis debate when it was determined that the universe had a larger scale than the Milky Way galaxy. This was precipitated by observations that established the size and the dynamics of the cosmos that could be explained by Einstein's General Theory of Relativity.
    [Show full text]
  • Our 'Island Universe' Transcript
    Our 'Island Universe' Transcript Date: Thursday, 30 October 2008 - 12:00AM OUR 'ISLAND UNIVERSE' Professor Ian Morison The Milky Way On a dark night with transparent skies, we can see a band of light across the sky that we call the Milky Way. (This comes from the Latin - Via Lactea.) The light comes from the myriads of stars packed so closely together that our eyes fail to resolve them into individual points of light. This is our view of our own galaxy, called the Milky Way Galaxy or often "the Galaxy" for short. It shows considerable structure due to obscuration by intervening dust clouds. The band of light is not uniform; the brightness and extent is greatest towards the constellation Sagittarius suggesting that in that direction we are looking towards the Galactic Centre. However, due to the dust, we are only able to see about one tenth of the way towards it. In the opposite direction in the sky the Milky Way is less apparent implying that we live out towards one side. Finally, the fact that we see a band of light tells us that the stars, gas and dust that make up the galaxy are in the form of a flat disc. Figure 1 An all-sky view of the Milky Way. The major visible constituent of the Galaxy, about 96%, is made up of stars, with the remaining 4% split between gas ~ 3% and dust ~ 1%. Here "visible" means that we can detect them by electromagnetic radiation; visible, infrared or radio. As we will discuss in detail in the next lecture, "The Invisible Universe", we suspect that there is a further component of the Galaxy that we cannot directly detect called "dark matter".
    [Show full text]
  • Coma Cluster of Galaxies
    Coma Cluster of Galaxies In 2006, Hubble Space Telescope aimed at a nearby collection of NATIONAL SCIENCE EDUCATION STA N D A R D S galaxies called the Coma Cluster. Using the HST images, astronomers • Content Standard in 9-12 Science as gained fascinating insights into the evolution of galaxies in dense Inquiry (Abilities necessary to do sci- galactic neighborhoods. In this activity, students will first learn the entific inquiry, Understanding about basics of galaxy classification and grouping, then use HST images to scientific inquiry) discover the “morphology-density effect” and make hypotheses about • Content Standard in 9-12 Earth and its causes. Space Science (Origin and evolution of the universe) MATERIALS & PRE PARATION • Each student needs a copy of the next 7 pages (not this page). You may InvIsIble Clu s t e r copy the pages out of this guide, but it is recommended that you go to If you aim a big telescope at the Coma mcdonaldobservatory.org/teachers/classroom and download the student Cluster, you’ll see galaxies galore worksheets. The galaxy images in the online worksheets are “negatives” — thousands of galaxies of all sizes of the real images, which provides better detail when printing. Supple- and shapes, from little puffballs to mental materials for this activity are also available on the website. big, fuzzy footballs. Even so, you won’t • Each student or student team will need a calculator and a magnifying see most of the cluster because it’s invis- glass (a linen tester works well). ible to human eyes. • Knowledge of percentages is needed before doing this activity.
    [Show full text]
  • Kapteyn Astronomical Institute 2003
    KAPTEYN ASTRONOMICAL INSTITUTE 2003 KAPTEYN ASTRONOMICAL INSTITUTE University of Groningen ANNUAL REPORT 2003 Groningen, May 2004 2 Cover: Multi-wavelength image of the nearby starburst galaxy NGC 253. The deep optical image is made by David Malin, the blue shows the bright optical disk as seen in the Digitized Sky Survey, the red is soft X-ray emission from ROSAT, and the green contours are neutral hydrogen from the Compact Array. (Boomsma, Oosterloo, Fraternali, Van der Hulst and Sancisi). Neutral hydrogen is now detected up to more than 10 kpc from the plane of the galaxy. This gas has probably been dragged up by the superwind produced by the central starburst. CONTENTS 1. FOREWORD............................................................................................ 1 2. EDUCATION............................................................................................ 7 3. RESEARCH ............................................................................................11 3.1 History of astronomy...............................................................................11 3.2 Stars .......................................................................................................11 3.3 Circumstellar Matter, Interstellar Medium, and Star Formation...............12 3.4 Structure and Dynamics of Galaxies.......................................................16 3.5 Quasars and Active Galaxies .................................................................32 3.6 Clusters, High-Redshift Galaxies and Large Scale Structure
    [Show full text]
  • Biennial Report 2006 2007 Published in Spain by the Isaac Newton Group of Telescopes (ING) ISSN 1575–8966 Legal License: TF–1142 /99
    I SAAC N EWTON G ROUP OF T ELESCOPES Biennial Report 2006 2007 Published in Spain by the Isaac Newton Group of Telescopes (ING) ISSN 1575–8966 Legal license: TF–1142 /99 Apartado de correos, 321 E-38700 Santa Cruz de La Palma; Canary Islands; Spain Tel: +34 922 425 400 Fax: +34 922 425 401 URL: http://www.ing.iac.es/ Editor and designer: Javier Méndez ([email protected]) Printing: Gráficas Sabater. Tel: +34 922 623 555 Front cover: The Milky Way from the site of the William Herschel Telescope. Credit: Nik Szymanek. Inset: Photograph of the WHT at sunset. Credit: Nik Szymanek. Other picture credits: Nik Szymanek (WHT, p. 4; INT, p. 4; JKT, p. 4; ING, p. 5); Jens Moser (WHT, back; INT, back); Nik Szymanek (JKT, back). The ING Biennial Report is available online at http://www.ing.iac.es/PR/AR/. ISAAC NEWTON GROUP OF TELESCOPES Biennial Report of the STFC-NWO-IAC ING Board 2006 – 2007 ISAAC NEWTON GROUP William Herschel Telescope Isaac Newton Telescope Jacobus Kapteyn Telescope 4 • ING BIENNIAL R EPORT 2006–2007 OF TELESCOPES The Isaac Newton Group of Telescopes (ING) consists of the 4.2- metre William Herschel Telescope (WHT), the 2.5-metre Isaac Newton Telescope (INT) and the 1.0-metre Jacobus Kapteyn Telescope (JKT). The ING is located 2350 metres above sea level at the Observatorio del Roque de los Muchachos (ORM) on the island of La Palma, Canary Islands, Spain. The WHT is the largest telescope of its kind in Western Europe. The construction, operation, and development of the ING telescopes are the result of a collaboration between the United Kingdom, The Netherlands and Spain.
    [Show full text]
  • Astronomy 113 Laboratory Manual
    UNIVERSITY OF WISCONSIN - MADISON Department of Astronomy Astronomy 113 Laboratory Manual Fall 2011 Professor: Snezana Stanimirovic 4514 Sterling Hall [email protected] TA: Natalie Gosnell 6283B Chamberlin Hall [email protected] 1 2 Contents Introduction 1 Celestial Rhythms: An Introduction to the Sky 2 The Moons of Jupiter 3 Telescopes 4 The Distances to the Stars 5 The Sun 6 Spectral Classification 7 The Universe circa 1900 8 The Expansion of the Universe 3 ASTRONOMY 113 Laboratory Introduction Astronomy 113 is a hands-on tour of the visible universe through computer simulated and experimental exploration. During the 14 lab sessions, we will encounter objects located in our own solar system, stars filling the Milky Way, and objects located much further away in the far reaches of space. Astronomy is an observational science, as opposed to most of the rest of physics, which is experimental in nature. Astronomers cannot create a star in the lab and study it, walk around it, change it, or explode it. Astronomers can only observe the sky as it is, and from their observations deduce models of the universe and its contents. They cannot ever repeat the same experiment twice with exactly the same parameters and conditions. Remember this as the universe is laid out before you in Astronomy 113 – the story always begins with only points of light in the sky. From this perspective, our understanding of the universe is truly one of the greatest intellectual challenges and achievements of mankind. The exploration of the universe is also a lot of fun, an experience that is largely missed sitting in a lecture hall or doing homework.
    [Show full text]