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SDSS DR7 Superclusters Morphology
A&A 532, A5 (2011) Astronomy DOI: 10.1051/0004-6361/201116564 & c ESO 2011 Astrophysics SDSS DR7 superclusters Morphology M. Einasto1,L.J.Liivamägi1,2,E.Tago1,E.Saar1,E.Tempel1,2,J.Einasto1, V. J. Martínez3, and P. Heinämäki4 1 Tartu Observatory, 61602 Tõravere, Estonia e-mail: [email protected] 2 Institute of Physics, Tartu University, Tähe 4, 51010 Tartu, Estonia 3 Observatori Astronòmic, Universitat de València, Apartat de Correus 22085, 46071 València, Spain 4 Tuorla Observatory, University of Turku, Väisäläntie 20, Piikkiö, Finland Received 24 January 2011 / Accepted 2 May 2011 ABSTRACT Aims. We study the morphology of a set of superclusters drawn from the SDSS DR7. Methods. We calculate the luminosity density field to determine superclusters from a flux-limited sample of galaxies from SDSS DR7 and select superclusters with 300 and more galaxies for our study. We characterise the morphology of superclusters using the fourth Minkowski functional V3, the morphological signature (the curve in the shapefinder’s K1-K2 plane) and the shape parameter (the ratio of the shapefinders K1/K2). We investigate the supercluster sample using multidimensional normal mixture modelling. We use Abell clusters to identify our superclusters with known superclusters and to study the large-scale distribution of superclusters. Results. The superclusters in our sample form three chains of superclusters; one of them is the Sloan Great Wall. Most superclusters have filament-like overall shapes. Superclusters can be divided into two sets; more elongated superclusters are more luminous, richer, have larger diameters and a more complex fine structure than less elongated superclusters. The fine structure of superclusters can be divided into four main morphological types: spiders, multispiders, filaments, and multibranching filaments. -
Cosmicflows-3: Cosmography of the Local Void
Draft version May 22, 2019 Preprint typeset using LATEX style AASTeX6 v. 1.0 COSMICFLOWS-3: COSMOGRAPHY OF THE LOCAL VOID R. Brent Tully, Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA Daniel Pomarede` Institut de Recherche sur les Lois Fondamentales de l'Univers, CEA, Universite' Paris-Saclay, 91191 Gif-sur-Yvette, France Romain Graziani University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN Lyon, France Hel´ ene` M. Courtois University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN Lyon, France Yehuda Hoffman Racah Institute of Physics, Hebrew University, Jerusalem, 91904 Israel Edward J. Shaya University of Maryland, Astronomy Department, College Park, MD 20743, USA ABSTRACT Cosmicflows-3 distances and inferred peculiar velocities of galaxies have permitted the reconstruction of the structure of over and under densities within the volume extending to 0:05c. This study focuses on the under dense regions, particularly the Local Void that lies largely in the zone of obscuration and consequently has received limited attention. Major over dense structures that bound the Local Void are the Perseus-Pisces and Norma-Pavo-Indus filaments sepa- rated by 8,500 km s−1. The void network of the universe is interconnected and void passages are found from the Local Void to the adjacent very large Hercules and Sculptor voids. Minor filaments course through voids. A particularly interesting example connects the Virgo and Perseus clusters, with several substantial galaxies found along the chain in the depths of the Local Void. The Local Void has a substantial dynamical effect, causing a deviant motion of the Local Group of 200 − 250 km s−1. -
Is the Universe Expanding?: an Historical and Philosophical Perspective for Cosmologists Starting Anew
Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 6-1996 Is the Universe Expanding?: An Historical and Philosophical Perspective for Cosmologists Starting Anew David A. Vlosak Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Cosmology, Relativity, and Gravity Commons Recommended Citation Vlosak, David A., "Is the Universe Expanding?: An Historical and Philosophical Perspective for Cosmologists Starting Anew" (1996). Master's Theses. 3474. https://scholarworks.wmich.edu/masters_theses/3474 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. IS THEUN IVERSE EXPANDING?: AN HISTORICAL AND PHILOSOPHICAL PERSPECTIVE FOR COSMOLOGISTS STAR TING ANEW by David A Vlasak A Thesis Submitted to the Faculty of The Graduate College in partial fulfillment of the requirements forthe Degree of Master of Arts Department of Philosophy Western Michigan University Kalamazoo, Michigan June 1996 IS THE UNIVERSE EXPANDING?: AN HISTORICAL AND PHILOSOPHICAL PERSPECTIVE FOR COSMOLOGISTS STARTING ANEW David A Vlasak, M.A. Western Michigan University, 1996 This study addresses the problem of how scientists ought to go about resolving the current crisis in big bang cosmology. Although this problem can be addressed by scientists themselves at the level of their own practice, this study addresses it at the meta level by using the resources offered by philosophy of science. There are two ways to resolve the current crisis. -
David Michael Karl the MAN BEHIND the SCIENCE
Noelo DELVE SEEK OUT VERIFY David Michael Karl THE MAN BEHIND THE SCIENCE RESEARCH AND INNOVATI ON AT THE UNIVERSITY OF HAWAI‘I - 2020 Delve. Delve. Verify. Seek. MESSAGE FROM THE VICE PRESIDENT University of Throughout history, the world has faced numerous Hawai‘i System health crises that have tested the mettle and resolve of its citizens — the Spanish flu, measles, polio, HIV/AIDS, David Lassner, PhD SARS and Ebola. Today, our world is confronted by the President COVID-19 pandemic, an unprecedented health crisis Vassilis L. Syrmos, PhD Vice President for that has rapidly spread across continents, overwhelmed Research and Innovation modern health care systems and caused widespread disruption of the global economy. NOELO, WHICH MEANS “to delVE, SEEK OUT OR verify” IN HAWAIIAN, IS Hawai‘i with its heavy dependency on tourism, is now at an economic crossroad. with high hotel THE RESEARCH MAGAZINE vacancies, idled tour operations and restricted air travel, other businesses such as restaurants and OF THE UNIVERSITY OF retail stores are also suffering from almost non-existent visitor counts. even after a vaccine for HAWai‘i SYSTEM PUBLISHED ANNUALLY BY THE OFFICE COVId-19 is developed or the effects of the disease are mitigated, the “new normal” may suggest OF THE VICE PRESIDENT FOR that changes to the travel industry and in visitor habits could result in smaller or diminishing RESEARCH AND INNOVATION. returns from the state’s primary industry. economic diversification is not only key to Hawai‘i’s economic recovery from the pandemic, PROJECT MANAGER it is also vital to its long-term economic stability and health. -
An Outline of Stellar Astrophysics with Problems and Solutions
An Outline of Stellar Astrophysics with Problems and Solutions Using Maple R and Mathematica R Robert Roseberry 2016 1 Contents 1 Introduction 5 2 Electromagnetic Radiation 7 2.1 Specific intensity, luminosity and flux density ............7 Problem 1: luminous flux (**) . .8 Problem 2: galaxy fluxes (*) . .8 Problem 3: radiative pressure (**) . .9 2.2 Magnitude ...................................9 Problem 4: magnitude (**) . 10 2.3 Colour ..................................... 11 Problem 5: Planck{Stefan-Boltzmann{Wien{colour (***) . 13 Problem 6: Planck graph (**) . 13 Problem 7: radio and visual luminosity and brightness (***) . 14 Problem 8: Sirius (*) . 15 2.4 Emission Mechanisms: Continuum Emission ............. 15 Problem 9: Orion (***) . 17 Problem 10: synchrotron (***) . 18 Problem 11: Crab (**) . 18 2.5 Emission Mechanisms: Line Emission ................. 19 Problem 12: line spectrum (*) . 20 2.6 Interference: Line Broadening, Scattering, and Zeeman splitting 21 Problem 13: natural broadening (**) . 21 Problem 14: Doppler broadening (*) . 22 Problem 15: Thomson Cross Section (**) . 23 Problem 16: Inverse Compton scattering (***) . 24 Problem 17: normal Zeeman splitting (**) . 25 3 Measuring Distance 26 3.1 Parallax .................................... 27 Problem 18: parallax (*) . 27 3.2 Doppler shifting ............................... 27 Problem 19: supernova distance (***) . 28 3.3 Spectroscopic parallax and Main Sequence fitting .......... 28 Problem 20: Main Sequence fitting (**) . 29 3.4 Standard candles ............................... 30 Video: supernova light curve . 30 Problem 21: Cepheid distance (*) . 30 3.5 Tully-Fisher relation ............................ 31 3.6 Lyman-break galaxies and the Hubble flow .............. 33 4 Transparent Gas: Interstellar Gas Clouds and the Atmospheres and Photospheres of Stars 35 2 4.1 Transfer equation and optical depth .................. 36 Problem 22: optical depth (**) . 37 4.2 Plane-parallel atmosphere, Eddington's approximation, and limb darkening .................................. -
The Hestia Project: Simulations of the Local Group
MNRAS 000,2{20 (2020) Preprint 13 August 2020 Compiled using MNRAS LATEX style file v3.0 The Hestia project: simulations of the Local Group Noam I. Libeskind1;2 Edoardo Carlesi1, Rob J. J. Grand3, Arman Khalatyan1, Alexander Knebe4;5;6, Ruediger Pakmor3, Sergey Pilipenko7, Marcel S. Pawlowski1, Martin Sparre1;8, Elmo Tempel9, Peng Wang1, H´el`ene M. Courtois2, Stefan Gottl¨ober1, Yehuda Hoffman10, Ivan Minchev1, Christoph Pfrommer1, Jenny G. Sorce11;12;1, Volker Springel3, Matthias Steinmetz1, R. Brent Tully13, Mark Vogelsberger14, Gustavo Yepes4;5 1Leibniz-Institut fur¨ Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany 2University of Lyon, UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, France 3Max-Planck-Institut fur¨ Astrophysik, Karl-Schwarzschild-Str. 1, D-85748, Garching, Germany 4Departamento de F´ısica Te´orica, M´odulo 15, Facultad de Ciencias, Universidad Aut´onoma de Madrid, 28049 Madrid, Spain 5Centro de Investigaci´on Avanzada en F´ısica Fundamental (CIAFF), Facultad de Ciencias, Universidad Aut´onoma de Madrid, 28049 Madrid, Spain 6International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia 7P.N. Lebedev Physical Institute of Russian Academy of Sciences, 84/32 Profsojuznaja Street, 117997 Moscow, Russia 8Potsdam University 9Tartu Observatory, University of Tartu, Observatooriumi 1, 61602 T~oravere, Estonia 10Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel 11Univ. Lyon, ENS de Lyon, Univ. Lyon I, CNRS, Centre de Recherche Astrophysique de Lyon, UMR5574, F-69007, Lyon, France 12Univ Lyon, Univ Lyon-1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230, Saint-Genis-Laval, France 13Institute for Astronomy (IFA), University of Hawaii, 2680 Woodlawn Drive, HI 96822, USA 14Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Accepted | . -
And Ecclesiastical Cosmology
GSJ: VOLUME 6, ISSUE 3, MARCH 2018 101 GSJ: Volume 6, Issue 3, March 2018, Online: ISSN 2320-9186 www.globalscientificjournal.com DEMOLITION HUBBLE'S LAW, BIG BANG THE BASIS OF "MODERN" AND ECCLESIASTICAL COSMOLOGY Author: Weitter Duckss (Slavko Sedic) Zadar Croatia Pусскй Croatian „If two objects are represented by ball bearings and space-time by the stretching of a rubber sheet, the Doppler effect is caused by the rolling of ball bearings over the rubber sheet in order to achieve a particular motion. A cosmological red shift occurs when ball bearings get stuck on the sheet, which is stretched.“ Wikipedia OK, let's check that on our local group of galaxies (the table from my article „Where did the blue spectral shift inside the universe come from?“) galaxies, local groups Redshift km/s Blueshift km/s Sextans B (4.44 ± 0.23 Mly) 300 ± 0 Sextans A 324 ± 2 NGC 3109 403 ± 1 Tucana Dwarf 130 ± ? Leo I 285 ± 2 NGC 6822 -57 ± 2 Andromeda Galaxy -301 ± 1 Leo II (about 690,000 ly) 79 ± 1 Phoenix Dwarf 60 ± 30 SagDIG -79 ± 1 Aquarius Dwarf -141 ± 2 Wolf–Lundmark–Melotte -122 ± 2 Pisces Dwarf -287 ± 0 Antlia Dwarf 362 ± 0 Leo A 0.000067 (z) Pegasus Dwarf Spheroidal -354 ± 3 IC 10 -348 ± 1 NGC 185 -202 ± 3 Canes Venatici I ~ 31 GSJ© 2018 www.globalscientificjournal.com GSJ: VOLUME 6, ISSUE 3, MARCH 2018 102 Andromeda III -351 ± 9 Andromeda II -188 ± 3 Triangulum Galaxy -179 ± 3 Messier 110 -241 ± 3 NGC 147 (2.53 ± 0.11 Mly) -193 ± 3 Small Magellanic Cloud 0.000527 Large Magellanic Cloud - - M32 -200 ± 6 NGC 205 -241 ± 3 IC 1613 -234 ± 1 Carina Dwarf 230 ± 60 Sextans Dwarf 224 ± 2 Ursa Minor Dwarf (200 ± 30 kly) -247 ± 1 Draco Dwarf -292 ± 21 Cassiopeia Dwarf -307 ± 2 Ursa Major II Dwarf - 116 Leo IV 130 Leo V ( 585 kly) 173 Leo T -60 Bootes II -120 Pegasus Dwarf -183 ± 0 Sculptor Dwarf 110 ± 1 Etc. -
An Astronomy Ubd for 8Th Grade Miguel Angel Webber [email protected]
Trinity University Digital Commons @ Trinity Understanding by Design: Complete Collection Understanding by Design 6-2019 Looking Up! What is our place in the universe? - An Astronomy UbD for 8th Grade Miguel Angel Webber [email protected] Follow this and additional works at: https://digitalcommons.trinity.edu/educ_understandings Repository Citation Webber, Miguel Angel, "Looking Up! What is our place in the universe? - An Astronomy UbD for 8th Grade" (2019). Understanding by Design: Complete Collection. 445. https://digitalcommons.trinity.edu/educ_understandings/445 This Instructional Material is brought to you for free and open access by the Understanding by Design at Digital Commons @ Trinity. For more information about this unie, please contact the author(s): [email protected]. For information about the series, including permissions, please contact the administrator: [email protected]. v 8GrSci Looking Up - What is our place in the universe? Unit Title Looking Up - What is our place in the universe? Course(s) 8th Grade Science Designed by Miguel Angel Webber Martinez Time Frame 17 Class Days: W1 August 26 - 30 (5) W2 September 3 - 6 (4) W3 September 9 - 13 (5) W4 September 16 - 18 (3) Stage 1- Desired Results Establish Goals 8th Grade Science TEKS ● 8.8A Describe components of the universe, including stars, nebulae, and galaxies. Use models such as the Hertzsprung-Russell diagram for classification. ● 8.8B Recognize that the Sun is a medium-sized star located in a spiral arm of the Milky Way galaxy, and that the Sun is many thousands of times closer to Earth than any other star. ● 8.8C Identify how different wavelengths of the electromagnetic spectrum, such as visible light and radio waves, are used to gain information about components in the universe. -
Astronomy 422
Astronomy 422 Lecture 15: Expansion and Large Scale Structure of the Universe Key concepts: Hubble Flow Clusters and Large scale structure Gravitational Lensing Sunyaev-Zeldovich Effect Expansion and age of the Universe • Slipher (1914) found that most 'spiral nebulae' were redshifted. • Hubble (1929): "Spiral nebulae" are • other galaxies. – Measured distances with Cepheids – Found V=H0d (Hubble's Law) • V is called recessional velocity, but redshift due to stretching of photons as Universe expands. • V=H0D is natural result of uniform expansion of the universe, and also provides a powerful distance determination method. • However, total observed redshift is due to expansion of the universe plus a galaxy's motion through space (peculiar motion). – For example, the Milky Way and M31 approaching each other at 119 km/s. • Hubble Flow : apparent motion of galaxies due to expansion of space. v ~ cz • Cosmological redshift: stretching of photon wavelength due to expansion of space. Recall relativistic Doppler shift: Thus, as long as H0 constant For z<<1 (OK within z ~ 0.1) What is H0? Main uncertainty is distance, though also galaxy peculiar motions play a role. Measurements now indicate H0 = 70.4 ± 1.4 (km/sec)/Mpc. Sometimes you will see For example, v=15,000 km/s => D=210 Mpc = 150 h-1 Mpc. Hubble time The Hubble time, th, is the time since Big Bang assuming a constant H0. How long ago was all of space at a single point? Consider a galaxy now at distance d from us, with recessional velocity v. At time th ago it was at our location For H0 = 71 km/s/Mpc Large scale structure of the universe • Density fluctuations evolve into structures we observe (galaxies, clusters etc.) • On scales > galaxies we talk about Large Scale Structure (LSS): – groups, clusters, filaments, walls, voids, superclusters • To map and quantify the LSS (and to compare with theoretical predictions), we use redshift surveys. -
Monthly Newsletter of the Durban Centre - March 2018
Page 1 Monthly Newsletter of the Durban Centre - March 2018 Page 2 Table of Contents Chairman’s Chatter …...…………………….……….………..….…… 3 Andrew Gray …………………………………………...………………. 5 The Hyades Star Cluster …...………………………….…….……….. 6 At the Eye Piece …………………………………………….….…….... 9 The Cover Image - Antennae Nebula …….……………………….. 11 Galaxy - Part 2 ….………………………………..………………….... 13 Self-Taught Astronomer …………………………………..………… 21 The Month Ahead …..…………………...….…….……………..…… 24 Minutes of the Previous Meeting …………………………….……. 25 Public Viewing Roster …………………………….……….…..……. 26 Pre-loved Telescope Equipment …………………………...……… 28 ASSA Symposium 2018 ………………………...……….…......…… 29 Member Submissions Disclaimer: The views expressed in ‘nDaba are solely those of the writer and are not necessarily the views of the Durban Centre, nor the Editor. All images and content is the work of the respective copyright owner Page 3 Chairman’s Chatter By Mike Hadlow Dear Members, The third month of the year is upon us and already the viewing conditions have been more favourable over the last few nights. Let’s hope it continues and we have clear skies and good viewing for the next five or six months. Our February meeting was well attended, with our main speaker being Dr Matt Hilton from the Astrophysics and Cosmology Research Unit at UKZN who gave us an excellent presentation on gravity waves. We really have to be thankful to Dr Hilton from ACRU UKZN for giving us his time to give us presentations and hope that we can maintain our relationship with ACRU and that we can draw other speakers from his colleagues and other research students! Thanks must also go to Debbie Abel and Piet Strauss for their monthly presentations on NASA and the sky for the following month, respectively. -
Dark Matter Particles with Low Mass (And FTL)
Dark Matter Particles with Low Mass (and FTL) Xiaodong Huang Department of Mathematics, University of California, Los Angeles Los Angeles, CA 90095, U.S.A. Wuliang Huang Institute of High Energy Physics, Chinese Academy of Sciences P.O. Box 918(3), Beijing 100049, China Abstract: From the observed results of the space distribution of quasars and the mass scale sequence table, we deduced the existence of superstructures (feeble dark structure) with mass scale of 1019 solar mass, as well as the lightest stable fermion with mass of 10"1 eV, in the universe. From the observed results of ultra-high energy primary cosmic ray spectrum (“knee” and “ankle”), quasar irradiation spectrum (“IR bump” and “blue bump”), and Extragalactic Background Light (“IR peak” and “blue peak”), we deduced that the mass of ! 1 ! the neutrino is about 10" eV and the mass of the fourth stable elementary particle (" ) is about 100eV. While neutrino ! is related to electro-weak field, the fourth stable elementary particle! is related to gravitation-“strong” field, and some new meta-stable baryons may appear near the TeV region. Therefore, a twofold standard model diagram is ! proposed, and! involves some experiment phenomena: The new meta-stable baryons’ ! decays produce! particles, which are helpful in explaining the Dijet asymmetry phenomena at LHC of CERN, the different results for the Fermilab’s data peak, etc; However, according to the (B-L) invariance, the sterile “neutrino” about the event excess in MiniBooNe is not the fourth neutrino but rather the! particle; We think that the! particles are related to the phenomenon about neutrinos FTL, and that anti-neutrinos are faster than neutrinos. -
Astronomers Map Massive Structure Beyond Laniakea Supercluster 13 July 2020
Astronomers map massive structure beyond Laniakea Supercluster 13 July 2020 the Milky Way. Along the arm, galaxies are slowly moving toward the South Pole, and from there, across a part of the sky obscured from Earth by the Milky Way toward the dominant structure in the nearby universe, the Shapley connection. "We wonder if the South Pole Wall is much bigger than what we see. What we have mapped stretches across the full domain of the region we have surveyed. We are early explorers of the cosmos, extending our maps into unknown territory," described Tully. The team's research was published in Astrophysical Journal. Throughout the last 40 years, there has been a growing appreciation of patterns in the distribution of galaxies in the Universe, reminiscent of geographic features like mountain ranges and island archipelagos. The Milky Way galaxy, with its South Pole Wall. Credit: University of Hawaii at Manoa 100 billion stars, is part of the small Local Group of galaxies, which in turn is a suburb of the Virgo cluster with thousands of galaxies. The Virgo cluster in turn is an outer component of an even For the past decade, an international team of larger conglomeration of many rich clusters of astronomers, led in part by Brent Tully at the galaxies, collectively called the "Great Attractor" University of Hawai?i Institute for Astronomy, has because of its immense gravitational pull. In 2014, been mapping the distribution of galaxies around the team mapped out the Laniakea Supercluster, the Milky Way. They have discovered an immense the bundling of a hundred thousand galaxies over structure beyond Laniakea, an immense an even larger region, spanning 500 million light supercluster of galaxies, including our own.