Interstellar Medium (ISM)
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Exploring Pulsars
High-energy astrophysics Explore the PUL SAR menagerie Astronomers are discovering many strange properties of compact stellar objects called pulsars. Here’s how they fit together. by Victoria M. Kaspi f you browse through an astronomy book published 25 years ago, you’d likely assume that astronomers understood extremely dense objects called neutron stars fairly well. The spectacular Crab Nebula’s central body has been a “poster child” for these objects for years. This specific neutron star is a pulsar that I rotates roughly 30 times per second, emitting regular appar- ent pulsations in Earth’s direction through a sort of “light- house” effect as the star rotates. While these textbook descriptions aren’t incorrect, research over roughly the past decade has shown that the picture they portray is fundamentally incomplete. Astrono- mers know that the simple scenario where neutron stars are all born “Crab-like” is not true. Experts in the field could not have imagined the variety of neutron stars they’ve recently observed. We’ve found that bizarre objects repre- sent a significant fraction of the neutron star population. With names like magnetars, anomalous X-ray pulsars, soft gamma repeaters, rotating radio transients, and compact Long the pulsar poster child, central objects, these bodies bear properties radically differ- the Crab Nebula’s central object is a fast-spinning neutron star ent from those of the Crab pulsar. Just how large a fraction that emits jets of radiation at its they represent is still hotly debated, but it’s at least 10 per- magnetic axis. Astronomers cent and maybe even the majority. -
Planetary Nebulae Jacob Arnold AY230, Fall 2008
Jacob Arnold Planetary Nebulae Jacob Arnold AY230, Fall 2008 1 PNe Formation Low mass stars (less than 8 M) will travel through the asymptotic giant branch (AGB) of the familiar HR-diagram. During this stage of evolution, energy generation is primarily relegated to a shell of helium just outside of the carbon-oxygen core. This thin shell of fusing He cannot expand against the outer layer of the star, and rapidly heats up while also quickly exhausting its reserves and transferring its head outwards. When the He is depleted, Hydrogen burning begins in a shell just a little farther out. Over time, helium builds up again, and very abruptly begins burning, leading to a shell-helium-flash (thermal pulse). During the thermal-pulse AGB phase, this process repeats itself, leading to mass loss at the extended outer envelope of the star. The pulsations extend the outer layers of the star, causing the temperature to drop below the condensation temperature for grain formation (Zijlstra 2006). Grains are driven off the star by radiation pressure, bringing gas with them through collisions. The mass loss from pulsating AGB stars is oftentimes referred to as a wind. For AGB stars, the surface gravity of the star is quite low, and wind speeds of ~10 km/s are more than sufficient to drive off mass. At some point, a super wind develops that removes the envelope entirely, a phenomenon not yet fully understood (Bernard-Salas 2003). The central, primarily carbon-oxygen core is thus exposed. These cores can have temperatures in the hundreds of thousands of Kelvin, leading to a very strong ionizing source. -
Introduction to Astronomy from Darkness to Blazing Glory
Introduction to Astronomy From Darkness to Blazing Glory Published by JAS Educational Publications Copyright Pending 2010 JAS Educational Publications All rights reserved. Including the right of reproduction in whole or in part in any form. Second Edition Author: Jeffrey Wright Scott Photographs and Diagrams: Credit NASA, Jet Propulsion Laboratory, USGS, NOAA, Aames Research Center JAS Educational Publications 2601 Oakdale Road, H2 P.O. Box 197 Modesto California 95355 1-888-586-6252 Website: http://.Introastro.com Printing by Minuteman Press, Berkley, California ISBN 978-0-9827200-0-4 1 Introduction to Astronomy From Darkness to Blazing Glory The moon Titan is in the forefront with the moon Tethys behind it. These are two of many of Saturn’s moons Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA 2 Introduction to Astronomy Contents in Brief Chapter 1: Astronomy Basics: Pages 1 – 6 Workbook Pages 1 - 2 Chapter 2: Time: Pages 7 - 10 Workbook Pages 3 - 4 Chapter 3: Solar System Overview: Pages 11 - 14 Workbook Pages 5 - 8 Chapter 4: Our Sun: Pages 15 - 20 Workbook Pages 9 - 16 Chapter 5: The Terrestrial Planets: Page 21 - 39 Workbook Pages 17 - 36 Mercury: Pages 22 - 23 Venus: Pages 24 - 25 Earth: Pages 25 - 34 Mars: Pages 34 - 39 Chapter 6: Outer, Dwarf and Exoplanets Pages: 41-54 Workbook Pages 37 - 48 Jupiter: Pages 41 - 42 Saturn: Pages 42 - 44 Uranus: Pages 44 - 45 Neptune: Pages 45 - 46 Dwarf Planets, Plutoids and Exoplanets: Pages 47 -54 3 Chapter 7: The Moons: Pages: 55 - 66 Workbook Pages 49 - 56 Chapter 8: Rocks and Ice: -
Lecture 3 - Minimum Mass Model of Solar Nebula
Lecture 3 - Minimum mass model of solar nebula o Topics to be covered: o Composition and condensation o Surface density profile o Minimum mass of solar nebula PY4A01 Solar System Science Minimum Mass Solar Nebula (MMSN) o MMSN is not a nebula, but a protoplanetary disc. Protoplanetary disk Nebula o Gives minimum mass of solid material to build the 8 planets. PY4A01 Solar System Science Minimum mass of the solar nebula o Can make approximation of minimum amount of solar nebula material that must have been present to form planets. Know: 1. Current masses, composition, location and radii of the planets. 2. Cosmic elemental abundances. 3. Condensation temperatures of material. o Given % of material that condenses, can calculate minimum mass of original nebula from which the planets formed. • Figure from Page 115 of “Physics & Chemistry of the Solar System” by Lewis o Steps 1-8: metals & rock, steps 9-13: ices PY4A01 Solar System Science Nebula composition o Assume solar/cosmic abundances: Representative Main nebular Fraction of elements Low-T material nebular mass H, He Gas 98.4 % H2, He C, N, O Volatiles (ices) 1.2 % H2O, CH4, NH3 Si, Mg, Fe Refractories 0.3 % (metals, silicates) PY4A01 Solar System Science Minimum mass for terrestrial planets o Mercury:~5.43 g cm-3 => complete condensation of Fe (~0.285% Mnebula). 0.285% Mnebula = 100 % Mmercury => Mnebula = (100/ 0.285) Mmercury = 350 Mmercury o Venus: ~5.24 g cm-3 => condensation from Fe and silicates (~0.37% Mnebula). =>(100% / 0.37% ) Mvenus = 270 Mvenus o Earth/Mars: 0.43% of material condensed at cooler temperatures. -
The MUSE View of the Planetary Nebula NGC 3132? Ana Monreal-Ibero1,2 and Jeremy R
A&A 634, A47 (2020) Astronomy https://doi.org/10.1051/0004-6361/201936845 & © ESO 2020 Astrophysics The MUSE view of the planetary nebula NGC 3132? Ana Monreal-Ibero1,2 and Jeremy R. Walsh3,?? 1 Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Universidad de La Laguna, Dpto. Astrofísica, 38206 La Laguna, Tenerife, Spain 3 European Southern Observatory, Karl-Schwarzschild Strasse 2, 85748 Garching, Germany Received 4 October 2019 / Accepted 6 December 2019 ABSTRACT Aims. Two-dimensional spectroscopic data for the whole extent of the NGC 3132 planetary nebula have been obtained. We deliver a reduced data-cube and high-quality maps on a spaxel-by-spaxel basis for the many emission lines falling within the Multi-Unit Spectroscopic Explorer (MUSE) spectral coverage over a range in surface brightness >1000. Physical diagnostics derived from the emission line images, opening up a variety of scientific applications, are discussed. Methods. Data were obtained during MUSE commissioning on the European Southern Observatory (ESO) Very Large Telescope and reduced with the standard ESO pipeline. Emission lines were fitted by Gaussian profiles. The dust extinction, electron densities, and temperatures of the ionised gas and abundances were determined using Python and PyNeb routines. 2 Results. The delivered datacube has a spatial size of 6300 12300, corresponding to 0:26 0:51 pc for the adopted distance, and ∼ × ∼ 1 × a contiguous wavelength coverage of 4750–9300 Å at a spectral sampling of 1.25 Å pix− . The nebula presents a complex reddening structure with high values (c(Hβ) 0:4) at the rim. -
Planetary Nebula Associations with Star Clusters in the Andromeda Galaxy Yasmine Kahvaz [email protected]
Marshall University Marshall Digital Scholar Theses, Dissertations and Capstones 2016 Planetary Nebula Associations with Star Clusters in the Andromeda Galaxy Yasmine Kahvaz [email protected] Follow this and additional works at: http://mds.marshall.edu/etd Part of the Stars, Interstellar Medium and the Galaxy Commons Recommended Citation Kahvaz, Yasmine, "Planetary Nebula Associations with Star Clusters in the Andromeda Galaxy" (2016). Theses, Dissertations and Capstones. 1052. http://mds.marshall.edu/etd/1052 This Thesis is brought to you for free and open access by Marshall Digital Scholar. It has been accepted for inclusion in Theses, Dissertations and Capstones by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. PLANETARY NEBULA ASSOCIATIONS WITH STAR CLUSTERS IN THE ANDROMEDA GALAXY A thesis submitted to the Graduate College of Marshall University In partial fulfillment of the requirements for the degree of Master of Physical and Applied Science in Physics by Yasmine Kahvaz Approved by Dr. Timothy Hamilton, Committee Chairperson Dr. Maria Babiuc Hamilton Dr. Ralph Oberly Marshall University Dec 2016 ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Timothy Hamilton at Shawnee State University, for his guidance, advice and support for all the aspects of this project. My committee, including Dr. Timothy Hamilton, Dr. Maria Babiuc Hamilton, and Dr. Ralph Oberly, provided a review of this thesis. This research has made use of the following databases: The Local Group Survey (low- ell.edu/users/massey/lgsurvey.html) and the PHAT Survey (archive.stsci.edu/prepds/phat/). I would also like to thank the entire faculty of the Physics Department of Marshall University for being there for me every step of the way through my undergrad and graduate degree years. -
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. -
Astronomy Astrophysics
A&A 432, 515–529 (2005) Astronomy DOI: 10.1051/0004-6361:20040331 & c ESO 2005 Astrophysics PAH charge state distribution and DIB carriers: Implications from the line of sight toward HD 147889, R. Ruiterkamp1,N.L.J.Cox2,M.Spaans3, L. Kaper2,B.H.Foing4,F.Salama5, and P. Ehrenfreund2 1 Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands e-mail: [email protected] 2 Institute Anton Pannekoek, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands 3 Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands 4 ESA Research and Scientific Support Department, PO Box 299, 2200 AG Noordwijk, The Netherlands 5 Space Science Division, NASA Ames Research Center, Mail Stop 245-6, Moffett Field, California 94035, USA Received 25 February 2004 / Accepted 29 September 2004 Abstract. We have computed physical parameters such as density, degree of ionization and temperature, constrained by a large observational data set on atomic and molecular species, for the line of sight toward the single cloud HD 147889. Diffuse interstellar bands (DIBs) produced along this line of sight are well documented and can be used to test the PAH hypothesis. To this effect, the charge state fractions of different polycyclic aromatic hydrocarbons (PAHs) are calculated in HD 147889 as a function of depth for the derived density, electron abundance and temperature profile. As input for the construction of these charge state distributions, the microscopic properties of the PAHs, e.g., ionization potential and electron affinity, are determined for a series of symmetry groups. The combination of a physical model for the chemical and thermal balance of the gas toward HD 147889 with a detailed treatment of the PAH charge state distribution, and laboratory and theoretical data on specific PAHs, allow us to compute electronic spectra of gas phase PAH molecules and to draw conclusions about the required properties of PAHs as DIB carriers. -
Physical Processes in the Interstellar Medium
Physical Processes in the Interstellar Medium Ralf S. Klessen and Simon C. O. Glover Abstract Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). Understand- ing its physical properties and dynamical behavior is of pivotal importance to many areas of astronomy and astrophysics. Galaxy formation and evolu- tion, the formation of stars, cosmic nucleosynthesis, the origin of large com- plex, prebiotic molecules and the abundance, structure and growth of dust grains which constitute the fundamental building blocks of planets, all these processes are intimately coupled to the physics of the interstellar medium. However, despite its importance, its structure and evolution is still not fully understood. Observations reveal that the interstellar medium is highly tur- bulent, consists of different chemical phases, and is characterized by complex structure on all resolvable spatial and temporal scales. Our current numerical and theoretical models describe it as a strongly coupled system that is far from equilibrium and where the different components are intricately linked to- gether by complex feedback loops. Describing the interstellar medium is truly a multi-scale and multi-physics problem. In these lecture notes we introduce the microphysics necessary to better understand the interstellar medium. We review the relations between large-scale and small-scale dynamics, we con- sider turbulence as one of the key drivers of galactic evolution, and we review the physical processes that lead to the formation of dense molecular clouds and that govern stellar birth in their interior. Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Straße 2, 69120 Heidelberg, Germany e-mail: [email protected], [email protected] 1 Contents Physical Processes in the Interstellar Medium ............... -
Laboratory Astrophysics: from Observations to Interpretation
April 14th – 19th 2019 Jesus College Cambridge UK IAU Symposium 350 Laboratory Astrophysics: From Observations to Interpretation Poster design by: D. Benoit, A. Dawes, E. Sciamma-O’Brien & H. Fraser Scientific Organizing Committee: Local Organizing Committee: Farid Salama (Chair) ★ P. Barklem ★ H. Fraser ★ T. Henning H. Fraser (Chair) ★ D. Benoit ★ R Coster ★ A. Dawes ★ S. Gärtner ★ C. Joblin ★ S. Kwok ★ H. Linnartz ★ L. Mashonkina ★ T. Millar ★ D. Heard ★ S. Ioppolo ★ N. Mason ★ A. Meijer★ P. Rimmer ★ ★ O. Shalabiea★ G. Vidali ★ F. Wa n g ★ G. Del-Zanna E. Sciamma-O’Brien ★ F. Salama ★ C. Wa lsh ★ G. Del-Zanna For more information and to contact us: www.astrochemistry.org.uk/IAU_S350 [email protected] @iaus350labastro 2 Abstract Book Scheduley Sunday 14th April . Pg. 2 Monday 15th April . Pg. 3 Tuesday 16th April . Pg. 4 Wednesday 17th April . Pg. 5 Thursday 18th April . Pg. 6 Friday 19th April . Pg. 7 List of Posters . .Pg. 8 Abstracts of Talks . .Pg. 12 Abstracts of Posters . Pg. 83 yPlenary talks (40') are indicated with `P', review talks (30') with `R', and invited talks (15') with `I'. Schedule Sunday 14th April 14:00 - 17:00 REGISTRATION 18:00 - 19:00 WELCOME RECEPTION 19:30 DINNER BAR OPEN UNTIL 23:00 Back to Table of Contents 2 Monday 15th April 09:00 { 10:00 REGISTRATION 09:00 WELCOME by F. Salama (Chair of SOC) SESSION 1 CHAIR: F. Salama 09:15 E. van Dishoeck (P) Laboratory astrophysics: key to understanding the Universe From Diffuse Clouds to Protostars: Outstanding Questions about the Evolution of 10:00 A. -
Size and Scale Attendance Quiz II
Size and Scale Attendance Quiz II Are you here today? Here! (a) yes (b) no (c) are we still here? Today’s Topics • “How do we know?” exercise • Size and Scale • What is the Universe made of? • How big are these things? • How do they compare to each other? • How can we organize objects to make sense of them? What is the Universe made of? Stars • Stars make up the vast majority of the visible mass of the Universe • A star is a large, glowing ball of gas that generates heat and light through nuclear fusion • Our Sun is a star Planets • According to the IAU, a planet is an object that 1. orbits a star 2. has sufficient self-gravity to make it round 3. has a mass below the minimum mass to trigger nuclear fusion 4. has cleared the neighborhood around its orbit • A dwarf planet (such as Pluto) fulfills all these definitions except 4 • Planets shine by reflected light • Planets may be rocky, icy, or gaseous in composition. Moons, Asteroids, and Comets • Moons (or satellites) are objects that orbit a planet • An asteroid is a relatively small and rocky object that orbits a star • A comet is a relatively small and icy object that orbits a star Solar (Star) System • A solar (star) system consists of a star and all the material that orbits it, including its planets and their moons Star Clusters • Most stars are found in clusters; there are two main types • Open clusters consist of a few thousand stars and are young (1-10 million years old) • Globular clusters are denser collections of 10s-100s of thousand stars, and are older (10-14 billion years -
Discovering Milky Way HII Regions
Discovering Milky Way HII Regions Tom Bania Institute for Astrophysical Research Department of Astronomy Boston University GBT HRDS Green Bank Telescope HII Region Discovery Survey AO HRDS AreciBo OBservatory HII Region Discovery Survey SHRDS Southern HII Region Discovery Survey Milky Way H II Regions HII regions are zones of ionizeD gas surrounDing O anD B type stars (Masses > 8 M¤ ) l Lifetimes <10 Myr → Trace star formation at present epoch Emit at radio wavelengths via Bremsstrahlung (free-free) continuum and radio recomBination line (RRL) emission → Thermal plasma emission mechanisms Emit at infrared (IR) due to presence of dust → The Brightest oBjects in the Galaxy at radio and IR wavelengths! The signature of HII regions is a high IR anD raDio flux H II Regions anD Galaxies The GBT Galactic H II Region Discovery Survey T.M. Bania (Boston University), L. D. Anderson (West Virginia University) Dana S. Balser (NRAO), and RoBert T. Rood (University of Virginia) GBT HRDS CollaBorators NormalizeD to Age 30 Tom Bania (Boston University) Dana Balser (NRAO) BoB RooD (University of Virginia) Loren Anderson (West Virginia University) H II Region Surveys Eagle NeBula NGC 6611 M 16 S 49 RCW 165 Gum 83 “Pillars of Creation” POSS RaDio Continuum Surveys Dwingeloo 25 m telescope 1390 MHz Westerhout (1958) RaDio RecomBination Lines (RRLs) H109α Antenna Temperature Antenna Frequency HoglunD & Mezger (1965) RaDio Wavelength Sky Surveys Continuum surveys Began in the 1950s Recombination line surveys Began in the 1960s MPIfR W43 100 m 4.875 GHz Altenhoff