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Stellar Tidal Streams As Cosmological Diagnostics: Comparing Data and Simulations at Low Galactic Scales
RUPRECHT-KARLS-UNIVERSITÄT HEIDELBERG DOCTORAL THESIS Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Author: Referees: Gustavo MORALES Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL Astronomisches Rechen-Institut Heidelberg Graduate School of Fundamental Physics Department of Physics and Astronomy 14th May, 2018 ii DISSERTATION submitted to the Combined Faculties of the Natural Sciences and Mathematics of the Ruperto-Carola-University of Heidelberg, Germany for the degree of DOCTOR OF NATURAL SCIENCES Put forward by GUSTAVO MORALES born in Copiapo ORAL EXAMINATION ON JULY 26, 2018 iii Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Referees: Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL iv NOTE: Some parts of the written contents of this thesis have been adapted from a paper submitted as a co-authored scientific publication to the Astronomy & Astrophysics Journal: Morales et al. (2018). v NOTE: Some parts of this thesis have been adapted from a paper accepted for publi- cation in the Astronomy & Astrophysics Journal: Morales, G. et al. (2018). “Systematic search for tidal features around nearby galaxies: I. Enhanced SDSS imaging of the Local Volume". arXiv:1804.03330. DOI: 10.1051/0004-6361/201732271 vii Abstract In hierarchical models of galaxy formation, stellar tidal streams are expected around most galaxies. Although these features may provide useful diagnostics of the LCDM model, their observational properties remain poorly constrained. Statistical analysis of the counts and properties of such features is of interest for a direct comparison against results from numeri- cal simulations. In this work, we aim to study systematically the frequency of occurrence and other observational properties of tidal features around nearby galaxies. -
Astronomy Magazine Special Issue
γ ι ζ γ δ α κ β κ ε γ β ρ ε ζ υ α φ ψ ω χ α π χ φ γ ω ο ι δ κ α ξ υ λ τ μ β α σ θ ε β σ δ γ ψ λ ω σ η ν θ Aι must-have for all stargazers η δ μ NEW EDITION! ζ λ β ε η κ NGC 6664 NGC 6539 ε τ μ NGC 6712 α υ δ ζ M26 ν NGC 6649 ψ Struve 2325 ζ ξ ATLAS χ α NGC 6604 ξ ο ν ν SCUTUM M16 of the γ SERP β NGC 6605 γ V450 ξ η υ η NGC 6645 M17 φ θ M18 ζ ρ ρ1 π Barnard 92 ο χ σ M25 M24 STARS M23 ν β κ All-in-one introduction ALL NEW MAPS WITH: to the night sky 42,000 more stars (87,000 plotted down to magnitude 8.5) AND 150+ more deep-sky objects (more than 1,200 total) The Eagle Nebula (M16) combines a dark nebula and a star cluster. In 100+ this intense region of star formation, “pillars” form at the boundaries spectacular between hot and cold gas. You’ll find this object on Map 14, a celestial portion of which lies above. photos PLUS: How to observe star clusters, nebulae, and galaxies AS2-CV0610.indd 1 6/10/10 4:17 PM NEW EDITION! AtlAs Tour the night sky of the The staff of Astronomy magazine decided to This atlas presents produce its first star atlas in 2006. -
The Outermost Hii Regions of Nearby Galaxies
THE OUTERMOST HII REGIONS OF NEARBY GALAXIES by Jessica K. Werk A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Astronomy and Astrophysics) in The University of Michigan 2010 Doctoral Committee: Professor Mario L. Mateo, Co-Chair Associate Professor Mary E. Putman, Co-Chair, Columbia University Professor Fred C. Adams Professor Lee W. Hartmann Associate Professor Marion S. Oey Professor Gerhardt R. Meurer, University of Western Australia Jessica K. Werk Copyright c 2010 All Rights Reserved To Mom and Dad, for all your love and encouragement while I was taking up space. ii ACKNOWLEDGMENTS I owe a deep debt of gratitude to a long list of individuals, institutions, and substances that have seen me through the last six years of graduate school. My first undergraduate advisor in Astronomy, Kathryn Johnston, was also my first Astronomy Professor. She piqued my interest in the subject from day one with her enthusiasm and knowledge. I don’t doubt that I would be studying something far less interesting if it weren’t for her. John Salzer, my next and last undergraduate advisor, not only taught me so much about observing and organization, but also is responsible for convincing me to go on in Astronomy. Were it not for John, I’d probably be making a lot more money right now doing something totally mind-numbing and soul-crushing. And Laura Chomiuk, a fellow Wesleyan Astronomy Alumnus, has been there for me through everything − problem sets and personal heartbreak alike. To know her as a friend, goat-lover, and scientist has meant so much to me over the last 10 years, that confining my gratitude to these couple sentences just seems wrong. -
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. -
Cold Gas Accretion in Galaxies
Astron Astrophys Rev (2008) 15:189–223 DOI 10.1007/s00159-008-0010-0 REVIEW ARTICLE Cold gas accretion in galaxies Renzo Sancisi · Filippo Fraternali · Tom Oosterloo · Thijs van der Hulst Received: 28 January 2008 / Published online: 17 April 2008 © The Author(s) 2008 Abstract Evidence for the accretion of cold gas in galaxies has been rapidly accumulating in the past years. H I observations of galaxies and their environment have brought to light new facts and phenomena which are evidence of ongoing or recent accretion: (1) A large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by H I cloud complexes, tails and filaments. This suggests ongoing minor mergers and recent arrival of external gas. It may be regarded, therefore, as direct evidence of cold gas accretion in the local universe. It is probably the same kind of phenomenon of material infall as the stellar streams observed in the halos of our galaxy and M 31. (2) Considerable amounts of extra-planar H I have been found in nearby spiral galaxies. While a large fraction of this gas is undoubtedly produced by galactic fountains, it is likely that a part of it is of extragalactic origin. Also the Milky Way has extra-planar gas complexes: the Intermediate- and High-Velocity Clouds (IVCs and HVCs). (3) Spirals are known to have extended and warped outer layers of H I. It is not clear how these have formed, and how and for how long the warps can R. Sancisi (B) Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy e-mail: [email protected] R. -
Revisiting the Low-Luminosity Galaxy Population of the NGC 5846 Group with SDSS
A&A 511, A12 (2010) Astronomy DOI: 10.1051/0004-6361/200811013 & c ESO 2010 Astrophysics Revisiting the low-luminosity galaxy population of the NGC 5846 group with SDSS P. Eigenthaler and W. W. Zeilinger Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, 1180 Vienna, Austria e-mail: [email protected] Received 22 September 2008 / Accepted 26 November 2009 ABSTRACT Context. Low-luminosity galaxies are known to outnumber the bright galaxy population in poor groups and clusters of galaxies. Yet, the investigation of low-luminosity galaxy populations outside the Local Group remains rare and the dependence on different group environments is still poorly understood. Previous investigations have uncovered the photometric scaling relations of early-type dwarfs and a strong dependence of morphology with environment. Aims. The present study aims to analyse the photometric and spectroscopic properties of the low-luminosity galaxy population in the nearby, well-evolved and early-type dominated NGC 5846 group of galaxies. It is the third most massive aggregate of early-type galaxies after the Virgo and Fornax clusters in the local universe. Photometric scaling relations and the distribution of morphological types as well as the characteristics of emission-line galaxies are investigated. Methods. Spectroscopically selected low-luminosity group members from the Sloan Digital Sky Survey with cz < 3000 km s−1 within aradiusof2◦ = 0.91 Mpc around NGC 5846 are analysed. Surface brightness profiles of early-type galaxies are fit by a Sérsic model ∝r1/n. Star formation rates, oxygen abundances, and emission characteristics are determined for emission-line galaxies. Results. Seven new group members showing no entry in previous catalogues are identified in the outer (>1.33◦) parts of the system. -
A Search For" Dwarf" Seyfert Nuclei. VII. a Catalog of Central Stellar
TO APPEAR IN The Astrophysical Journal Supplement Series. Preprint typeset using LATEX style emulateapj v. 26/01/00 A SEARCH FOR “DWARF” SEYFERT NUCLEI. VII. A CATALOG OF CENTRAL STELLAR VELOCITY DISPERSIONS OF NEARBY GALAXIES LUIS C. HO The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 JENNY E. GREENE1 Department of Astrophysical Sciences, Princeton University, Princeton, NJ ALEXEI V. FILIPPENKO Department of Astronomy, University of California, Berkeley, CA 94720-3411 AND WALLACE L. W. SARGENT Palomar Observatory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 To appear in The Astrophysical Journal Supplement Series. ABSTRACT We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being rela- −1 tively late-type systems with low velocity dispersions (∼<100kms ). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can ac- commodate composite stellar populations by calculating an optimal linear combination of input stellar templates. The original Palomar survey data were taken under conditions that are not ideally suited for deriving stellar veloc- ity dispersions for galaxies with a wide range of Hubble types. We describe an effective strategy to circumvent this complication and demonstrate that we can still obtain reliable velocity dispersions for this sample of well-studied nearby galaxies. Subject headings: galaxies: active — galaxies: kinematics and dynamics — galaxies: nuclei — galaxies: Seyfert — galaxies: starburst — surveys 1. INTRODUCTION tors, apertures, observing strategies, and analysis techniques. -
The Galaxy in Context: Structural, Kinematic & Integrated Properties
The Galaxy in Context: Structural, Kinematic & Integrated Properties Joss Bland-Hawthorn1, Ortwin Gerhard2 1Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006, Australia; email: [email protected] 2Max Planck Institute for extraterrestrial Physics, PO Box 1312, Giessenbachstr., 85741 Garching, Germany; email: [email protected] Annu. Rev. Astron. Astrophys. 2016. Keywords 54:529{596 Galaxy: Structural Components, Stellar Kinematics, Stellar This article's doi: 10.1146/annurev-astro-081915-023441 Populations, Dynamics, Evolution; Local Group; Cosmology Copyright c 2016 by Annual Reviews. Abstract All rights reserved Our Galaxy, the Milky Way, is a benchmark for understanding disk galaxies. It is the only galaxy whose formation history can be stud- ied using the full distribution of stars from faint dwarfs to supergiants. The oldest components provide us with unique insight into how galaxies form and evolve over billions of years. The Galaxy is a luminous (L?) barred spiral with a central box/peanut bulge, a dominant disk, and a diffuse stellar halo. Based on global properties, it falls in the sparsely populated \green valley" region of the galaxy colour-magnitude dia- arXiv:1602.07702v2 [astro-ph.GA] 5 Jan 2017 gram. Here we review the key integrated, structural and kinematic pa- rameters of the Galaxy, and point to uncertainties as well as directions for future progress. Galactic studies will continue to play a fundamen- tal role far into the future because there are measurements that can only be made in the near field and much of contemporary astrophysics depends on such observations. 529 Redshift (z) 20 10 5 2 1 0 1012 1011 ) ¯ 1010 M ( 9 r i 10 v 8 M 10 107 100 101 102 ) c p 1 k 10 ( r i v r 100 10-1 0.3 1 3 10 Time (Gyr) Figure 1 Left: The estimated growth of the Galaxy's virial mass (Mvir) and radius (rvir) from z = 20 to the present day, z = 0. -
ROTATING GALACTIC ARMS and LEADING-EDGE SHOCK WAVES in H 111 by Robert E
NASA TECHNICAL NOTE NASA TN D-2810 I -- c'- / 0 bo N d z c 4 VI 4 z ROTATING GALACTIC ARMS AND LEADING-EDGE SHOCK WAVES IN H 111 by Robert E. Duuidson Langley ReseurcrS Center Lungley Stution, Hampton, Vu, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 0 WASHINGTON, D. C. 0 MAY 1965 ROTATING GALACTIC ARMS AND LEADING-EDGE SHOCK WAVES IN H 111 By Robert E. Davidson Langley Research Center Langley Station, Hampton, Va. NATIONAL AERONAUT ICs AND SPACE ADMINISTRATION For sale by the Clearinghouse for Federal Scientific and Technical Information Springfield, Virginia 22151 - Price $1.00 ROTATING GALACTIC ARMS AND LEADING-EDGE SHOCK WAVES IN H I11 By Robert E. Davidson Langley Research Center SUMMARY A steady-state galactic-structure theory based on magnetohydrodynamic prin- ciples has been developed. Quasi-steady states, however, are not excluded. The theory provides an energy source for the coronal heating called for in the the- ories of Pickelner and Spitzer. The magnitude of the energy source can be cal- culated and appears adequate for Spitzer's theory and possibly is adequate for Pickelner's theory. In order to agree with other aspects of our knowledge of spiral galaxies, barred spirals in particular, it is necessary to assume that spiral arms are shaped by supersonic drag with attendant shocks. The angular motion of the galactic arms through the gas in the disk produces a flow over the arms which is subsonic within a certain distance of the galactic center and is supersonic outside it. From resulting aerodynamic effects an explanation of important galactic phenomena can be made. -
Studying Late-Type Spiral Galaxies Using SDSS Pohlen, M.; Trujillo, I
University of Groningen The structure of galactic disks - Studying late-type spiral galaxies using SDSS Pohlen, M.; Trujillo, I. Published in: Astronomy & astrophysics DOI: 10.1051/0004-6361:20064883 IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Final author's version (accepted by publisher, after peer review) Publication date: 2006 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Pohlen, M., & Trujillo, I. (2006). The structure of galactic disks - Studying late-type spiral galaxies using SDSS. Astronomy & astrophysics, 454(3), 759-U66. https://doi.org/10.1051/0004-6361:20064883 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date: 27-09-2021 Astronomy & Astrophysics manuscript no. SDSS May 5, 2006 (DOI: will be inserted by hand later) The structure of galactic disks Studying late-type spiral galaxies using SDSS M. Pohlen1,2 and I. -
1985Apjs ... 59 ...IW the Astrophysical Journal Supplement Series, 59:1-21,1985 September © 1985. the American Astronomical S
IW The Astrophysical Journal Supplement Series, 59:1-21,1985 September .... © 1985. The American Astronomical Society. All rights reserved. Printed in U.S.A. 59 ... A CATALOG OF STELLAR VELOCITY DISPERSIONS. I. 1985ApJS COMPILATION AND STANDARD GALAXIES Bradley C. Whitmore Space Telescope Science Institute Douglas B. McElroy Computer Sciences Corporation1 AND John L. Tonry California Institute of Technology Received 1984 October 23; accepted 1985 February 19 ABSTRACT A catalog of central stellar velocity dispersion measurements is presented, current through 1984 June. The catalog includes 1096 measurements of 725 galaxies. A set of 51 standard galaxies is defined which consists of galaxies with at least three reliable, concordant measurements. We suggest that future studies observe some of these standard galaxies in the course of their observations so that different studies can be normalized to the same system. We compare previous studies with the derived standards to determine relative accuracies and to compute scale factors where necessary. Subject headings: galaxies: internal motions I. INTRODUCTION be flattened by rotation. Results from Whitmore, Rubin, and The ability to make accurate measurements of stellar veloc- Ford (1984) conflict with the Kormendy and Illingworth con- ity dispersions has provided a major catalyst for the study of clusion. galactic structure and dynamics. Several important discoveries While most dispersion profiles are either flat or falling, have resulted from the use of this new tool. For example, a studies of cD galaxies at the center of rich clusters of galaxies correlation between the luminosity of an elliptical galaxy and have shown rising dispersion profiles (Dressier 1979; Carter the central stellar velocity dispersion was discovered by Faber et al 1981). -
DGSAT: Dwarf Galaxy Survey with Amateur Telescopes
Astronomy & Astrophysics manuscript no. arxiv30539 c ESO 2017 March 21, 2017 DGSAT: Dwarf Galaxy Survey with Amateur Telescopes II. A catalogue of isolated nearby edge-on disk galaxies and the discovery of new low surface brightness systems C. Henkel1;2, B. Javanmardi3, D. Mart´ınez-Delgado4, P. Kroupa5;6, and K. Teuwen7 1 Max-Planck-Institut f¨urRadioastronomie, Auf dem H¨ugel69, 53121 Bonn, Germany 2 Astronomy Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia 3 Argelander Institut f¨urAstronomie, Universit¨atBonn, Auf dem H¨ugel71, 53121 Bonn, Germany 4 Astronomisches Rechen-Institut, Zentrum f¨urAstronomie, Universit¨atHeidelberg, M¨onchhofstr. 12{14, 69120 Heidelberg, Germany 5 Helmholtz Institut f¨ur Strahlen- und Kernphysik (HISKP), Universit¨at Bonn, Nussallee 14{16, D-53121 Bonn, Germany 6 Charles University, Faculty of Mathematics and Physics, Astronomical Institute, V Holeˇsoviˇck´ach 2, CZ-18000 Praha 8, Czech Republic 7 Remote Observatories Southern Alps, Verclause, France Received date ; accepted date ABSTRACT The connection between the bulge mass or bulge luminosity in disk galaxies and the number, spatial and phase space distribution of associated dwarf galaxies is a dis- criminator between cosmological simulations related to galaxy formation in cold dark matter and generalised gravity models. Here, a nearby sample of isolated Milky Way- class edge-on galaxies is introduced, to facilitate observational campaigns to detect the associated families of dwarf galaxies at low surface brightness. Three galaxy pairs with at least one of the targets being edge-on are also introduced. Approximately 60% of the arXiv:1703.05356v2 [astro-ph.GA] 19 Mar 2017 catalogued isolated galaxies contain bulges of different size, while the remaining objects appear to be bulgeless.