The Evolution of the Hubble Sequence: Morpho-Kinematics of Distant Galaxies
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Thesis University of Western Australia
Kinematic and Environmental Regulation of Atomic Gas in Galaxies Jie Li March 2019 Master Thesis University of Western Australia Supervisors: Dr. Danail Obreschkow Dr. Claudia Lagos Dr. Charlotte Welker 20/05/2019 Acknowledgments I would like to thank my supervisors Danail Obreschkow, Claudia Lagos and Charlotte Welker for their guidance and support during this project, Luca Cortese, Robert Dˇzudˇzar and Garima Chauhan for their useful suggestions, my parents for giving me financial support and love, and ICRAR for o↵ering an open and friendly environments. Abstract Recent studies of neutral atomic hydrogen (H i) in nearby galaxies find that all isolated star-forming disk-dominated galaxies, from low-mass dwarfs to massive spirals systems, are H i saturated, in that they carry roughly (within a factor 1.5) as much H i fraction as permitted before this gas becomes gravitationally unstable. By taking this H i saturation for granted, the atomic gas fraction fatm of galactic disks can be predicted as a function of a stability parameter q j/M,whereM and j are the baryonic mass and specific / angular momentum of the disk (Obreschkow et al., 2016). The (logarithmic) di↵erence ∆fq between this predictor and the observed atomic fraction can thus be seen as a physically motivated way of defining a ‘H i deficiency’. While isolated disk galaxies have ∆f 0, q ⇡ objects subject to environmental removal/suppression of H i are expected to have ∆fq > 0. Within this framework, we revisit the H i deficiencies of satellite galaxies in the Virgo cluster (from the VIVA sample), as well as in clusters of the EAGLE simulation. -
Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305
43 Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305 This report covers astronomical research carried out during protostellar outflows have this much momentum out to rela- the period July 1, 1994 – June 30, 1995. Astronomical tively large distances. Planetary nebulae do not, but with studies at the Department of Terrestrial Magnetism ~DTM! their characteristic high post-shock temperatures, collapse of the Carnegie Institution of Washington encompass again occurs. Hence all three outflows appear to be able to observational and theoretical fields of solar system and trigger the collapse of molecular clouds to form stars. planet formation and evolution, stars and star formation, Foster and Boss are continuing this work and examining galaxy kinematics and evolution, and various areas where the possibility of introducing 26Al into the early solar system these fields intersect. in a heterogeneous manner. Some meteoritical inclusions ~chondrules! show no evidence for live 26Al at the time of their formation. So either the chondrules formed after the 1. PERSONNEL aluminium had decayed away, or the solar nebula was not Staff Members: Sean C. Solomon ~Director!, Conel M. O’D. Alexander, Alan P. Boss, John A. Graham, Vera C. Rubin, uniformly populated with the isotope. Foster & Boss are ex- Franc¸ois Schweizer, George W. Wetherill ploring the injection of shock wave particles into the collaps- Postdoctoral Fellows: Harold M. Butner, John E. Chambers, ing solar system. Preliminary results are that ;40% of the Prudence N. Foster, Munir Humayun, Stacy S. McGaugh, incident shock particles are swallowed by the collapsing Bryan W. Miller, Elizabeth A. Myhill, David L. -
Modeling and Interpretation of the Ultraviolet Spectral Energy Distributions of Primeval Galaxies
Ecole´ Doctorale d'Astronomie et Astrophysique d'^Ile-de-France UNIVERSITE´ PARIS VI - PIERRE & MARIE CURIE DOCTORATE THESIS to obtain the title of Doctor of the University of Pierre & Marie Curie in Astrophysics Presented by Alba Vidal Garc´ıa Modeling and interpretation of the ultraviolet spectral energy distributions of primeval galaxies Thesis Advisor: St´ephane Charlot prepared at Institut d'Astrophysique de Paris, CNRS (UMR 7095), Universit´ePierre & Marie Curie (Paris VI) with financial support from the European Research Council grant `ERC NEOGAL' Composition of the jury Reviewers: Alessandro Bressan - SISSA, Trieste, Italy Rosa Gonzalez´ Delgado - IAA (CSIC), Granada, Spain Advisor: St´ephane Charlot - IAP, Paris, France President: Patrick Boisse´ - IAP, Paris, France Examinators: Jeremy Blaizot - CRAL, Observatoire de Lyon, France Vianney Lebouteiller - CEA, Saclay, France Dedicatoria v Contents Abstract vii R´esum´e ix 1 Introduction 3 1.1 Historical context . .4 1.2 Early epochs of the Universe . .5 1.3 Galaxytypes ......................................6 1.4 Components of a Galaxy . .8 1.4.1 Classification of stars . .9 1.4.2 The ISM: components and phases . .9 1.4.3 Physical processes in the ISM . 12 1.5 Chemical content of a galaxy . 17 1.6 Galaxy spectral energy distributions . 17 1.7 Future observing facilities . 19 1.8 Outline ......................................... 20 2 Modeling spectral energy distributions of galaxies 23 2.1 Stellar emission . 24 2.1.1 Stellar population synthesis codes . 24 2.1.2 Evolutionary tracks . 25 2.1.3 IMF . 29 2.1.4 Stellar spectral libraries . 30 2.2 Absorption and emission in the ISM . 31 2.2.1 Photoionization code: CLOUDY ....................... -
Arxiv:1704.01678V2 [Astro-Ph.GA] 28 Jul 2017 Been Notoriously Difficult, Resulting Mostly in Upper Lim- Highest Escape Fractions Measured to Date Among Low- Its (E.G
Submitted: 3 March 2017 Preprint typeset using LATEX style AASTeX6 v. 1.0 MRK 71 / NGC 2366: THE NEAREST GREEN PEA ANALOG Genoveva Micheva1, M. S. Oey1, Anne E. Jaskot2, and Bethan L. James3 (Accepted 24 July 2017) 1University of Michigan, 311 West Hall, 1085 S. University Ave, Ann Arbor, MI 48109-1107, USA 2Department of Astronomy, Smith College, Northampton, MA 01063, USA 3STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA ABSTRACT We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H II region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitation properties, specific star-formation rate, kinematics, absorption of low-ionization species, reddening, and chemical abundance, and find consistencies throughout. Since extreme GPs are associated with both candidate and confirmed Lyman continuum (LyC) emitters, Mrk 71/NGC 2366 is thus also a good candidate for LyC escape. The spatially resolved data for this object show a superbubble blowout generated by mechanical feedback from one of its two super star clusters (SSCs), Knot B, while the extreme ionization properties are driven by the . 1 Myr-old, enshrouded SSC Knot A, which has ∼ 10 times higher ionizing luminosity. Very massive stars (> 100 M ) may be present in this remarkable object. Ionization-parameter mapping indicates the blowout region is optically thin in the LyC, and the general properties also suggest LyC escape in the line of sight. -
The Hubble Space Telescope – 10 Years On
BEN 11/7/00 2:27 PM Page 2 r bulletin 104 — november 2000 10 BEN 11/7/00 2:28 PM Page 3 the hubble space telescope – 10 years on The Hubble Space Telescope – 10 Years On P. Benvenuti & L. Lindberg Christensen ESA/ESO Space Telescope European Coordinating Facility, Garching, Germany Introduction scientists at the Space Telescope Science ESA is NASA’s partner in the Hubble Space Institute in Baltimore (STScI), USA. In return, a Telescope Project. ESA built the Faint Object minimum of 15% of the Telescope’s observing Camera (the HST instrument that delivers time is guaranteed for projects and research images with the highest spatial resolution), submitted by European astronomers from provided the solar panels that power the ESA’s Member States. In reality, the spacecraft, and supports a team of 15 high standard of projects from European astronomers has, so far, won them some 20% of the total observing time. Last Christmas Eve was very special one for ESA astronauts Claude Nicollier and Jean-François Clervoy: together with their American The initial ESA/NASA Memorandum of colleagues, they spent it aboard the Space Shuttle ‘Discovery’, after Understanding on HST expires 11 years after its concluding the latest scheduled repair mission to the orbiting Hubble launch, i.e. in April 2001. Both ESA and NASA Space Telescope (HST). This third Shuttle refurbishment mission to are convinced that the collaboration on HST has HST was, like its two predecessors, a resounding success. Only days been very successful, not merely in the later, as Hubble entered the new millennium, came the first beautiful development and initial operation of the images of a complex gravitationally lensing cluster of galaxies. -
The Recent and Continuing Assembly of Field Ellipticals by Red Mergers Pieter G
ACCEPTED FOR PUBLICATION IN THE ASTRONOMICAL JOURNAL (DECEMBER 2005 ISSUE) Preprint typeset using LATEX style emulateapj v. 11/12/01 THE RECENT AND CONTINUING ASSEMBLY OF FIELD ELLIPTICALS BY RED MERGERS PIETER G. VAN DOKKUM Department of Astronomy, Yale University, New Haven, CT 06520-8101; [email protected] Accepted for publication in the Astronomical Journal (December 2005 issue) ABSTRACT We present a study of tidal debris associated with 126 nearby red galaxies, selected from the 1.2 degree2 Multiwavelength Survey by Yale-Chile (MUSYC) and the 9.3 degree2 NOAO Deep Wide-Field Survey. In the full sample 67 galaxies (53 %) show morphological signatures of tidal interactions, consisting of broad fans of stars, tails, and other asymmetries at very faint surface brightness levels. When restricting the sample to the 86 bulge-dominated early-type galaxies the fraction of tidally disturbed galaxies rises to 71 %, which implies that for every “normal” undisturbed elliptical there are two which show clear signs of interactions. The tidal features are red and smooth, and often extend over 50 kpc. Of the tidally distorted galaxies about 2 ¡ 3 are remnants and 1 ¡ 3 are interacting with a companion galaxy. The companions are usually bright red galaxies as well: the median R-band luminosity ratio of the tidal pairs is 0.31, and the median color difference after correcting for the slope £ ¢ of the color-magnitude relation is ¢ 0 02 in B R. If the ongoing mergers are representative for the progenitors of the remnants ¤ 35 % of bulge-dominated galaxies experienced a merger with mass ratio 1 : 4 in the recent past. -
Download Date 30/09/2021 18:12:24
GALAXY ANGULAR MOMENTUM Item Type text; Dissertation-Reproduction (electronic) Authors Thompson, Laird Alan, 1947- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 30/09/2021 18:12:24 Link to Item http://hdl.handle.net/10150/288356 INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While ihs most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. t 1.The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. You will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., was part of the material being photographed the photographer followed a definite method in "sectioning" the material. -
Properties of Simulated Milky Way-Mass Galaxies in Loose Group and field Environments
A&A 547, A63 (2012) Astronomy DOI: 10.1051/0004-6361/201219649 & c ESO 2012 Astrophysics Properties of simulated Milky Way-mass galaxies in loose group and field environments C. G. Few1,B.K.Gibson1,2,3,S.Courty4, L. Michel-Dansac4,C.B.Brook5, and G. S. Stinson6 1 Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE, UK e-mail: [email protected] 2 Department of Astronomy & Physics, Saint Mary’s University, Halifax, Nova Scotia, B3H 3C3, Canada 3 Monash Centre for Astrophysics, Monash University, 3800 Victoria, Australia 4 Université de Lyon, Université Lyon 1, Observatoire de Lyon, CNRS, UMR 5574, Centre de Recherche Astrophysique de Lyon, École Normale Supérieure de Lyon, 9 avenue Charles André, 69230 Saint-Genis Laval, France 5 Grupo de Astrofísica, Departamento de Fisica Teorica, Modulo C-15, Universidad Autónoma de Madrid, 28049 Cantoblanco, Spain 6 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany Received 22 May 2012 / Accepted 27 September 2012 ABSTRACT Aims. We test the validity of comparing simulated field disk galaxies with the empirical properties of systems situated within envi- ronments more comparable to loose groups, including the Milky Way’s Local Group. Methods. Cosmological simulations of Milky Way-mass galaxies have been realised in two different environment samples: in the field and in loose groups environments with similar properties to the Local Group. Apart from the differing environments of the galaxies, the samples are kept as homogeneous as possible with equivalent ranges in last major merger time, halo mass and halo spin. Comparison of these two samples allow for systematic differences in the simulations to be identified. -
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. -
Galaxy Classification Questions of the Day
Galaxy classification Questions of the Day • What are elliptical, spiral, lenticular and dwarf galaxies? • What is the Hubble sequence? • What determines the colors of galaxies? Top View of the Milky Way The MW is a “spiral” galaxy, or a “late type” galaxy. The different components have different colors, motions, and chemical compositions different origins! Other Late Type Spiral Galaxies • More disk than bulge (if any!). • High current star formation. These are also “late-type” galaxies. Apparent shape depends on orientation Other Types: “Early type galaxies” • More bulge than disk. • Low current star formation. “Sombrero Galaxy” And even earlier type galaxies: • Elliptical Galaxies (or just “ellipticals”) – No disk! All bulge! Have evolved to the point – Very little gas where no gas is left for – Probably old! making new stars! “spheroidals” And in between, “lenticulars” • Just a hint of a disk. • Low current star formation. “S0” galaxies: Like ellipticals, but usually a bit flatter. Many galaxies have “bars” – linear arrangements of stars (The Milky Way has a bar!) All of these different types of galaxy fit nicely into a sequence. Ellipticals Unbarred and Barred Spirals Lenticulars Number indicates how flat the elliptical is Lowercase “a”, “b”, “c” indicates how unlike the spiral is to an elliptical Things that vary along the Hubble Sequence: 1. “Bulge-to-Disk Ratio” 2. Lumpiness of the spiral arms 3. How tightly the spiral arms are wound E Sa Sb Sc “early type” “late type” Things that vary along the Hubble Sequence: 1. “Bulge-to-Disk Ratio” 2. Lumpiness of the spiral arms 3. How tightly the spiral arms are wound E Sa Sb Sc Note: These are not exact trends! Galaxies are much more complex than stars! 1. -
The Evolution of Galaxy Morphology
The Morphological Evolution of Galaxies Roberto G. Abraham Sidney van den Bergh Dept. of Astronomy & Dominion Astrophysical Observatory Astrophysics Herzberg Institute of Astrophysics University of Toronto National Research Council of Canada 60 St. George Street Victoria, British Columbia Toronto, Ontario M5S 3H8, V9E 2E7, Canada Canada ABSTRACT Many galaxies appear to have taken on their familiar appearance relatively recently. In the distant Universe, galaxy morphology started to deviate significantly (and systematically) from that of nearby galaxies at redshifts, z, as low as z = 0.3. This corresponds to a time ~3.5 Gyr in the past, which is only ~25% of the present age of the Universe. Beyond z = 0.5 (5 Gyr in the past) spiral arms are less well-developed and more chaotic, and barred spiral galaxies may become rarer. By z = 1, around 30% of the galaxy population is sufficiently peculiar that classification on Hubble’s traditional “tuning fork” system is meaningless. On the other hand, some characteristics of galaxies do not seem to have changed much over time. The co-moving space density of luminous disk galaxies has not changed significantly since z = 1, indicating that while the general appearance of these objects has continuously changed with cosmic epoch, their overall numbers have been conserved. Attempts to explain these results with hierarchical models for the formation of galaxies have met with mixed success. denoted Sa, Sb, and Sc (SBa, SBb, SBc in of Hubble’s classification system are Introduction the case of barred spirals). A final “catch- based on the idea that most matter in the all” category for irregular galaxies is also Universe is not in stellar or gaseous form, Nearby galaxies are usually classified on included. -
Upper Limits on the Presence of Central Massive Black Holes in Two Ultra-Compact Dwarf Galaxies in Centaurus A
The Astrophysical Journal, 858:20 (15pp), 2018 May 1 https://doi.org/10.3847/1538-4357/aabae5 © 2018. The American Astronomical Society. All rights reserved. Upper Limits on the Presence of Central Massive Black Holes in Two Ultra-compact Dwarf Galaxies in Centaurus A Karina T. Voggel1 , Anil C. Seth1, Nadine Neumayer2 , Steffen Mieske3, Igor Chilingarian4,5 , Christopher Ahn1 , Holger Baumgardt6, Michael Hilker7, Dieu D. Nguyen1 , Aaron J. Romanowsky8,9 , Jonelle L. Walsh10 , Mark den Brok11, and Jay Strader12 1 University of Utah, Department of Physics & Astronomy, 115 S 1400 E, Salt Lake City, UT 84105, USA; [email protected] 2 Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany 3 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile 4 Smithsonian Astrophysical Observatory, 60 Garden Street MS09, 02138 Cambridge, MA, USA 5 Sternberg Astronomical Institute, M.V. Lomonosov Moscow State University, 13 Universitetsky prospect, 119992 Moscow, Russia 6 School of Mathematics and Physics, University of Queensland, St. Lucia, QLD 4072, Australia 7 European Southern Observatory, Karl-Schwarzschild-Straße 2, D-85748 Garching bei München, Germany 8 Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192, USA 9 University of California Observatories, 1156 High Street, Santa Cruz, CA 95064, USA 10 George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843,