Kinematics and Metallicity of RGB Stars in the Triangulum (M33) Galaxy This Dissertation Is Submitted for the Degree of Master of Science

Total Page:16

File Type:pdf, Size:1020Kb

Kinematics and Metallicity of RGB Stars in the Triangulum (M33) Galaxy This Dissertation Is Submitted for the Degree of Master of Science Kinematics and Metallicity of RGB Stars in the Triangulum (M33) Galaxy This dissertation is submitted for the degree of Master of Science David Trethewey Institute of Astronomy & Robinson College University of Cambridge April 28, 2011 ii Preface Declaration This dissertation is the result of my own work and includes nothing which is the outcome of work done in collaboration except where specifically indicated in the text. No part of this dissertation has been submitted for any other degree or qualification. This dissertation does not exceed 60,000 words. iii Figure 1: An image of the sky centred on M31 (upper right) and M33 (lower left), taken by the author using a Nikon D50 (at 70mm focal length) piggybacked on the Thorrowgood telescope mount at the Institute of Astronomy, Cambridge. 10 mins exposure, a background flattening routine is applied using MaxIm DL to reduce the visual impact of light pollution. iv Acknowledgements I thank my supervisors, Scott Chapman and Mike Irwin for guiding me in my research during my time at the Institute, and other members of the Institute of Astronomy who have also helped me in my academic life. I thank my office mates in O26 (and the now demolished SPO13) at the Institute of Astronomy; Scott Brown, Tim Staley, Duncan Hanson, Christopher Berry, Jonathan Crass, and other fellow graduate students I have known during my time here. I would also like to thank all of the IoA support staff, for everything from computing to morning coffee at the Institute. I thank the students, fellows and staff of Robinson College for the role they have played in the last nine years of my life, one third of my time on this Earth to date. One of them, Matt Davis as a PhD student in Geophysics always said he was more “down to earth” than me. I would like to thank the editors of Astronomy Now, noting that my interest in astronomy really began at the age of eight, with the January 1993 issue of that magazine. I also thank others who have been important in guiding me through my time as a graduate student. I thank Tony James, Peter Squibb, Mick Harvey and other members of the Cornwall Astronomical Society, through which my interest in astronomy developed. I also thank the people of the IAYC (International Astronomical Youth Camp) who I enjoyed spending time with in the forests of Central Europe. Finally I thank my family, for encouraging me and supporting me at every stage. v vi Abstract Kinematics and Metallicity of RGB Stars in the Triangulum (M33) Galaxy David Trethewey Eleven Keck DEIMOS (DEep Imaging Multi Object Spectrometer) fields around the Triangulum Galaxy (M33) are analysed in this work in combination with CFHT (Canada France Hawaii Telescope) photometry taken as part of the PAndAS (Pan-Andromeda Archaeological Survey) survey (McConnachie et al., 2009), containing a total of 2000 targets. A stellar population of candidate M33 RGB (Red Giant Branch) stars ∼ that is not rotating with the M33 disk is detected in most fields. The relative contribution of this population is estimated using kinematic windowing, both using a method of hard “disk” and “halo” kinematic windows in radial velocity and a Bayesian method taking account of priors for the expected disk and halo radial velocity distributions and relative contributions. The “disk” component has an exponential scale length of 1.7 kpc, agreeing with previous photometric work. If the non-disk population is assumed to be a “true” ∼ smooth halo, and fit by an exponential, it would contribute far more (9% of the disk luminosity integrated at 1% Bayesian halo prior and 17% integrated using simple windowing) than is indicated by photometric surveys (such as the INT-WFC (Isaac Newton Telescope Wide Field Camera) survey as published in Ferguson et al. 2007) and theoretical expectations, which constrain the contribution of a smooth stellar halo to the overall luminosity to less than a few percent. The metallicity properties of both the “disk” and “halo” samples are analysed. Photometric metallicities are derived using the Dartmouth isochrones (Dotter et al., 2008), and spectroscopic metallicities are derived from the equivalent widths of the Ca II triplet of stacked spectra. The “disk” shows a downward metallicity 1 trend with radius on the major axis of a magnitude 0.02-0.04 dex kpc− consistent between the photometric and spectroscopic analyses, which in the photometric analysis is significant at the 2σ level. The “halo” sample 1 shows a downward metallicity trend with radius on the major axis of a magnitude 0.04-0.05 dex kpc− in the photometric analysis, but this is not significant at 2σ level, and can be taken to be consistent with constant [Fe/H]. In the spectroscopic analysis, the metallicity trend of the halo is stronger, being of magnitude 0.11- 1 0.14 dex kpc− and significant at a 2σ level. The overall weighted mean [Fe/H]s of the “halo” sample across all fields, are -1.37 and -1.07 in the spectroscopic (CaT2 only) and photometric analyses respectively, and for the “disk” sample, -0.93 and -0.97. It is likely that the “halo” sample is largely the result of tidal stripping during a past interaction with M31 rather than a “true” primordial halo. vii viii Contents 1 Introduction 1 1.1 Andromeda and Triangulum historically . ...... 1 1.1.1 Distances to galaxies in the Local Group . ....... 4 1.2 Galaxy formation and motivation for the present study . ............. 4 1.2.1 The structure of galaxies . ..... 5 1.3 Near-field cosmology in the Local Group . ....... 7 1.3.1 Review of the study of galaxy formation and near-field cosmology. ........ 7 1.4 Introduction to the Local Group . ....... 8 1.4.1 The Local Group in context . .... 8 1.4.2 Basic parameters of the Milky Way, Andromeda and Triangulum galaxies ....... 10 1.4.3 Satellites of the major Local Group galaxies . ......... 14 1.5 TheTriangulumGalaxy ................................. ...... 17 1.5.1 Context of its relation to Andromeda . ...... 17 1.5.2 Previous work on Triangulum . ..... 17 1.5.3 DistancetoM33 ................................... 21 2 Context - The INT and PAndAS surveys and DEIMOS spectroscopic observations 23 2.1 Photometric studies . ...... 23 2.1.1 TheINTWFCsurvey .................................. 23 2.1.2 PAndAS - the Pan-Andromeda Archaeological Survey . 23 2.2 Spectroscopic work with DEIMOS . ...... 26 2.2.1 Technical detail about the DEIMOS instrument and its operation . ...... 26 2.2.2 The use of DEIMOS to observe Andromeda and Triangulum . 30 2.2.3 Targetselection................................... ..... 30 2.2.4 Accuracy of radial velocity and metallicity measurements. ....... 30 2.2.5 Summary of scientific work using DEIMOS on M31 . 30 2.2.6 TheDEIMOSdatainM33 ............................... 32 3 M33 disk and halo in the DEIMOS data 35 3.1 Processing of the pipelined data . ...... 35 3.1.1 Kinematic summary plots . 35 3.1.2 Diskrotation .................................. ....... 40 ix 3.1.3 Milky Way dwarf contamination . ....... 41 3.1.4 Quality cuts to the data . 46 3.1.5 Kinematic windowing . 47 3.2 Halo and disk profiles . ..... 50 3.2.1 Bayesianselection ................................. ..... 50 3.2.2 Simple kinematic windowing . 52 3.2.3 Halo/diskratios ................................ ....... 52 3.3 The outer two fields - EC2 and 511TrS . ..... 56 3.4 Halo velocity dispersions . ......... 56 3.5 Photometric metallicities - how photometry in various colour bands can provide information onmetallicity........................................ ..... 61 3.5.1 Consequences of the distance assumption . 61 3.5.2 Effect of age and alpha assumptions on photometric metallicity results . ........ 65 3.6 Spectroscopic metallicities . ........ 66 3.6.1 Stacking the spectra . 66 3.6.2 Effect of distance of the [Fe/H] calibration . ....... 77 3.7 Overall trends in metallicity . ........ 78 4 Discussion 83 4.1 Thediskprofile....................................... ..... 83 4.1.1 General properties of the disk . 83 4.1.2 The disk scale length . 83 4.2 Thehaloprofile....................................... ..... 84 4.2.1 Comparing the observed “halo” population to photometric surveys. ........ 84 4.2.2 Theoretical expectations . 87 4.3 Metallicity and age properties . ......... 88 4.3.1 Disk.......................................... 89 4.3.2 Halo.......................................... 92 4.4 Modelling of a possible interaction between M31 and M33 . ......... 93 4.5 The “halo” population - genuine stellar halo or stripped disk material? ............. 97 A Summary of M31 DEIMOS Fields 101 B [Fe/H] results for various combinations of CaT lines 105 C Tables of the individual stars 107 x List of Figures 1 An image of the Andromeda-Triangulum area of the sky . iv 1.1 A drawing of M33 based on Lord Rosse’s observations . ......... 2 1.2 Early photographs of M33 and M31 . ...... 3 1.3 The Hubble “tuning fork” classification of galaxies. .......... 6 1.4 Spatial density of SDSS stars around the north Galactic cap showing the Sagittarius and other streams............................................. .... 9 1.5 Visible light and near-IR (2MASS) all-sky panoramas . ......... 12 1.6 The distribution of Local Group members, as viewed from two orthogonal directions. 15 1.7 Structural properties of galaxies. (from Tolstoy et al. 2009) . ............... 16 1.8 M33 from the 2nd Palomar Digitised Sky Survey . ........ 18 1.9 Positions of fields studied in M33 in the literature . .......... 19 2.1 CoverageoftheINTsurveyofM31. ........ 24 2.2 CoverageoftheINTsurveyofM33. ........ 25 2.3 Coverage of the PAndAS survey. ...... 27 2.4 A diagram showing the mounting of DEIMOS on Keck II. ...... 28 2.5 The optics of the DEIMOS instrument. ..... 29 2.6 Locations of the DEIMOS spectroscopic masks around M31 and M33 shown on an image of the PAndAS survey . 31 2.7 The locations of the M33 DEIMOS masks on a section of an image of the PAndAS survey. 33 3.1 Velocity histogram for the 7 southern DEIMOS masks in M33.
Recommended publications
  • Draft181 182Chapter 10
    Chapter 10 Formation and evolution of the Local Group 480 Myr <t< 13.7 Gyr; 10 >z> 0; 30 K > T > 2.725 K The fact that the [G]alactic system is a member of a group is a very fortunate accident. Edwin Hubble, The Realm of the Nebulae Summary: The Local Group (LG) is the group of galaxies gravitationally associ- ated with the Galaxy and M 31. Galaxies within the LG have overcome the general expansion of the universe. There are approximately 75 galaxies in the LG within a 12 diameter of ∼3 Mpc having a total mass of 2-5 × 10 M⊙. A strong morphology- density relation exists in which gas-poor dwarf spheroidals (dSphs) are preferentially found closer to the Galaxy/M 31 than gas-rich dwarf irregulars (dIrrs). This is often promoted as evidence of environmental processes due to the massive Galaxy and M 31 driving the evolutionary change between dwarf galaxy types. High Veloc- ity Clouds (HVCs) are likely to be either remnant gas left over from the formation of the Galaxy, or associated with other galaxies that have been tidally disturbed by the Galaxy. Our Galaxy halo is about 12 Gyr old. A thin disk with ongoing star formation and older thick disk built by z ≥ 2 minor mergers exist. The Galaxy and M 31 will merge in 5.9 Gyr and ultimately resemble an elliptical galaxy. The LG has −1 vLG = 627 ± 22 km s with respect to the CMB. About 44% of the LG motion is due to the infall into the region of the Great Attractor, and the remaining amount of motion is due to more distant overdensities between 130 and 180 h−1 Mpc, primarily the Shapley supercluster.
    [Show full text]
  • Perseus I and the NGC 3109 Association in the Context of the Local Group Dwarf Galaxy Structures
    MNRAS 440, 908–919 (2014) doi:10.1093/mnras/stu321 Advance Access publication 2014 March 15 Perseus I and the NGC 3109 association in the context of the Local Group dwarf galaxy structures Marcel S. Pawlowski‹ and Stacy S. McGaugh Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA Accepted 2014 February 13. Received 2014 February 13; in original form 2014 January 8 ABSTRACT The recently discovered dwarf galaxy Perseus I appears to be associated with the dominant Downloaded from plane of non-satellite galaxies in the Local Group (LG). We predict its velocity dispersion and those of the other isolated dwarf spheroidals Cetus and Tucana to be 6.5, 8.2 and 5.5 km s−1, respectively. The NGC 3109 association, including the recently discovered dwarf galaxy Leo P, aligns with the dwarf galaxy structures in the LG such that all known nearby non-satellite http://mnras.oxfordjournals.org/ galaxies in the northern Galactic hemisphere lie in a common thin plane (rms height 53 kpc; diameter 1.2 Mpc). This plane has an orientation similar to the preferred orbital plane of the Milky Way (MW) satellites in the vast polar structure. Five of seven of these northern galaxies were identified as possible backsplash objects, even though only about one is expected from cosmological simulations. This may pose a problem, or instead the search for local backsplash galaxies might be identifying ancient tidal dwarf galaxies expelled in a past major galaxy encounter. The NGC 3109 association supports the notion that material preferentially falls towards the MW from the Galactic south and recedes towards the north, as if the MW were moving through a stream of dwarf galaxies.
    [Show full text]
  • 2.4 Colisión De Galaxias
    Simulación de colisión de dos galaxias para estudiar la formación de las galaxias enanas esferoidales satélites de la Vía Láctea Omar Alfonso Bohórquez Pacheco Universidad Nacional de Colombia Facultad de Ciencias, Departamento de Física Bogotá, Colombia 2016 Simulación de colisión de dos galaxias para estudiar la formación de las galaxias enanas esferoidales satélites de la Vía Láctea Omar Alfonso Bohórquez Pacheco Trabajo de grado presentado como requisito parcial para optar al título de: Magister en Ciencias - Física Director: Dr. rer. nat. Rigoberto Casas Miranda Grupo de Investigación: Astrofísica Universidad Nacional de Colombia Facultad de Ciencias, Departamento de Física Bogotá, Colombia 2016 A mis padres y en especial a mi abuela Esther Vega viuda de Pacheco, sin su ayuda no hubiera sido posible. Posible es que me equivoque y tome por oro y diamantes lo que solo es cobre y vidrio. René Descartes Agradecimientos Un gran agradecimiento al CECAD - Centro de Computación de Alto Desempeño de la Universidad Distrital “Francisco José de Caldas” y a mis amigos José Benavides, Diana Judith Cubillos Jara y Yeimy Camargo, sin su ayuda no habría sido posible. Resumen y Abstract IX Resumen En la actualidad dentro del área de la astrofísica se presentan un sinnúmero de problemas sin resolver, entre ellos el problema del origen de las galaxias satélite de la VL. Estas galaxias se caracterizan por ser de tipo enana esferoidal. La mayoría de estas se encuentran distribuidas en una estructura tipo disco que se encuentra dispuesta de casi forma perpendicular al plano de la galaxia, esta estructura es conocida con el nombre de disco de satélites (DoS) o Vast Polar Structure Of Satellite Galaxies (VPOS).
    [Show full text]
  • Monitoring Survey of Pulsating Giant Stars in the M
    Journal of Physics: Conference Series PAPER • OPEN ACCESS Related content - MASS LOSS AND R 136A-TYPE STARS. Monitoring survey of pulsating giant stars in the M. S. Vardya - M33 IR Variable Stars Local Group galaxies: survey description, science K. B. W. McQuinn, Charles E. Woodward, goals, target selection S. P. Willner et al. - MASS LOSS FROM EVOLVED STARS Robert J. Sopka To cite this article: E Saremi et al 2017 J. Phys.: Conf. Ser. 869 012068 View the article online for updates and enhancements. This content was downloaded from IP address 160.5.148.227 on 19/10/2017 at 09:54 Frontiers in Theoretical and Applied Physics/UAE 2017 (FTAPS 2017) IOP Publishing IOP Conf. Series: Journal of Physics: Conf. Series 1234567890869 (2017) 012068 doi :10.1088/1742-6596/869/1/012068 Monitoring survey of pulsating giant stars in the Local Group galaxies: survey description, science goals, target selection E Saremi1,2, A Javadi2, J Th van Loon3, H Khosroshahi2, A Abedi1, J Bamber3, S A Hashemi4, F Nikzat5 and A Molaei Nezhad2 1 Physics Department, University of Birjand, Birjand 97175-615, Iran 2 School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran, 19395-5531, Iran 3 Lennard-Jones Laboratories, Keele University, ST5 5BG, UK 4 Physics Department, Sharif University of Tecnology, Tehran 1458889694, Iran 5 Instituto de Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, 782-0436 Macul, Santiago, Chile Email: [email protected] Abstract. The population of nearby dwarf galaxies in the Local Group constitutes a complete galactic environment, perfect suited for studying the connection between stellar populations and galaxy evolution.
    [Show full text]
  • Watkins Laura.Pdf (PDF, 5Mb)
    Tracer Populations in the Local Group This dissertation is submitted for the degree of Doctor of Philosophy by Laura Louise Watkins Institute of Astronomy & Gonville and Caius College University of Cambridge 31st January 2011 For Mum and Dad, who gave me wings so I could fly and a nest to come home to Contents Declaration ix Acknowledgments xi Summary xiii 1 Introduction 1 1.1 Structure formation..................................................3 1.1.1 Dark matter...................................................3 1.1.2 Overview of current structure formation theory.........................4 1.1.3 Overmerging and the missing satellite problem.........................6 1.1.4 Dominance and survivability of structure.............................7 1.2 The Milky Way......................................................8 1.2.1 The bulge....................................................8 1.2.2 The thin disk..................................................9 1.2.3 The thick disk................................................. 10 1.2.4 The halo..................................................... 11 1.3 The Andromeda galaxy................................................ 18 1.4 Dwarf spheroidal galaxies.............................................. 22 1.4.1 Milky Way dwarfs............................................... 22 1.4.2 M31 dwarfs................................................... 23 1.4.3 Comparison with star clusters...................................... 24 1.4.4 Dwarf properties............................................... 26 1.5
    [Show full text]
  • Arxiv:1204.1562V2
    The observed properties of dwarf galaxies in and around the Local Group Alan W. McConnachie [email protected] NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, B.C., V9E 2E7, Canada Received ; accepted Submitted to AJ, December 22 2011 arXiv:1204.1562v2 [astro-ph.CO] 5 May 2012 –2– ABSTRACT Positional, structural and dynamical parameters for all dwarf galaxies in and around the Local Group are presented, and various aspects of our observational understanding of this volume-limited sample are discussed. Over 100 nearby galaxies that have distance estimates reliably placing them within 3 Mpc of the Sun are identified. This distance threshold samples dwarfs in a large range of en- vironments, from the satellite systems of the MW and M31, to the quasi-isolated dwarfs in the outer regions of the Local Group, to the numerous isolated galaxies that are found in its surroundings. It extends to, but does not include, the galax- ies associated with the next nearest groups, such as Maffei, Sculptor, and IC342. Our basic knowledge of this important galactic subset and their resolved stellar populations will continue to improve dramatically over the coming years with ex- isting and future observational capabilities, and they will continue to provide the most detailed information available on numerous aspects of dwarf galaxy forma- tion and evolution. Basic observational parameters, such as distances, velocities, magnitudes, mean metallicities, as well as structural and dynamical character- istics, are collated, homogenized (as far as possible), and presented in tables that will be continually updated to provide a convenient and current on-line resource.
    [Show full text]
  • Impact Des Fusions Majeures Sur L'evolution Des Galaxies Spirales Et
    Impact des fusions majeures sur l’evolution des galaxies spirales et naines Sylvain Fouquet To cite this version: Sylvain Fouquet. Impact des fusions majeures sur l’evolution des galaxies spirales et naines. Astro- physique galactique [astro-ph.GA]. Université Paris-Diderot - Paris VII, 2013. Français. tel-00975096 HAL Id: tel-00975096 https://tel.archives-ouvertes.fr/tel-00975096 Submitted on 7 Apr 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. UNIVERSITÉ PARIS. DIDEROT (Paris 7) École doctorale d’Astronomie et d’Astrophysique d’Île de France Observatoire de Paris-Meudon Laboratoire Galaxies, Étoiles, Physique et Instrumentation - UMR 8111 THÈSE Présentée en vue de l’obtention du titre de : Docteur en astronomie par Sylvain FOUQUET Impact des fusions majeures sur l’évolution des galaxies spirales et naines Thèse dirigée par François Hammer Soutenue le 24 juin 2013 M. Didier Pelat, Président M. François Hammer, Directeur de thèse M. Pavel Kroupa, Rapporteur M. Rodrigo Ibata, Rapporteur Mme Simona Mei, Examinateur M. Albert Bosma, Examinateur Remerciements La thèse comme la plupart de ce que l’on accomplit n’est pas une oeuvre personnelle mais le résultat d’une collaboration.
    [Show full text]
  • The Observed Properties of Dwarf Galaxies in and Around the Local Group
    The Astronomical Journal,144:4(36pp),2012July doi:10.1088/0004-6256/144/1/4 C 2012. National Research Council Canada. All rights reserved. Printed in the U.S.A. ! THE OBSERVED PROPERTIES OF DWARF GALAXIES IN AND AROUND THE LOCAL GROUP Alan W. McConnachie NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7, Canada; [email protected] Received 2011 December 22; accepted 2012 April 2; published 2012 June 4 ABSTRACT Positional, structural, and dynamical parameters for all dwarf galaxies in and around the Local Group are presented, and various aspects of our observational understanding of this volume-limited sample are discussed. Over 100 nearby galaxies that have distance estimates reliably placing them within 3 Mpc of the Sun are identified. This distance threshold samples dwarfs in a large range of environments, from the satellite systems of the MW and M31, to the quasi-isolated dwarfs in the outer regions of the Local Group, to the numerous isolated galaxies that are found in its surroundings. It extends to, but does not include, the galaxies associated with the next nearest groups, such as Maffei, Sculptor, and IC 342. Our basic knowledge of this important galactic subset and their resolved stellar populations will continue to improve dramatically over the coming years with existing and future observational capabilities, and they will continue to provide the most detailed information available on numerous aspects of dwarf galaxy formation and evolution. Basic observational parameters, such as distances, velocities, magnitudes, mean metallicities, as well as structural and dynamical characteristics, are collated, homogenized (as far as possible), and presented in tables that will be continually updated to provide a convenient and current online resource.
    [Show full text]
  • A Kinematic Study of the Andromeda Dwarf Spheroidal System
    The Astrophysical Journal, 768:172 (36pp), 2013 May 10 doi:10.1088/0004-637X/768/2/172 C 2013. The American Astronomical Society. All rights reserved. Printed in the U.S.A. A KINEMATIC STUDY OF THE ANDROMEDA DWARF SPHEROIDAL SYSTEM Michelle L. M. Collins1,2, Scott C. Chapman2,3, R. Michael Rich4, Rodrigo A. Ibata5, Nicolas F. Martin1,5, Michael J. Irwin2, Nicholas F. Bate6, Geraint F. Lewis6, Jorge Penarrubia˜ 7,8,15, Nobuo Arimoto9,10, Caitlin M. Casey11, Annette M. N. Ferguson8, Andreas Koch12, Alan W. McConnachie13, and Nial Tanvir14 1 Max-Planck-Institut fur¨ Astronomie, Konigstuhl¨ 17, D-69117 Heidelberg, Germany 2 Institute of Astronomy, Madingley Rise, Cambridge CB3 0HA, UK 3 Dalhousie University Department of Physics and Atmospheric Science Coburg Road, Halifax B3H1A6, Canada 4 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547, USA 5 Observatoire astronomique de Strasbourg, Universit de Strasbourg, CNRS, UMR 7550, 11 rue de lUniversit, F-67000 Strasbourg, France 6 Sydney Institute for Astronomy, School of Physics, A28, University of Sydney, NSW 2006, Australia 7 Instituto de Astrof´ısica de Andalucia-CSIC, Glorieta de la Astronom´ıa s/n, E-18008 Granada, Spain 8 Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK 9 Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI 96720, USA 10 Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 11 Institute for Astronomy,
    [Show full text]
  • Tracer Populations in the Local Group
    Tracer Populations in the Local Group This dissertation is submitted for the degree of Doctor of Philosophy by Laura Louise Watkins Institute of Astronomy & Gonville and Caius College University of Cambridge January 31st 2011 For Mum and Dad, who gave me wings so I could fly and a nest to come home to Contents Declaration ix Acknowledgments xi Summary xiii 1 Introduction 1 1.1 Structure formation..................................................3 1.1.1 Dark matter...................................................3 1.1.2 Overview of current structure formation theory.........................4 1.1.3 Overmerging and the missing satellite problem.........................6 1.1.4 Dominance and survivability of structure.............................7 1.2 The Milky Way......................................................8 1.2.1 The bulge....................................................8 1.2.2 The thin disk..................................................9 1.2.3 The thick disk................................................. 10 1.2.4 The halo..................................................... 11 1.3 The Andromeda galaxy................................................ 18 1.4 Dwarf spheroidal galaxies.............................................. 22 1.4.1 Milky Way dwarfs............................................... 22 1.4.2 M31 dwarfs................................................... 23 1.4.3 Comparison with star clusters...................................... 24 1.4.4 Dwarf properties............................................... 26 1.5
    [Show full text]
  • The Large-Scale Structure of the Halo of the Andromeda Galaxy II
    Draft version October 29, 2018 A Typeset using L TEX default style in AASTeX62 The large-scale structure of the halo of the Andromeda galaxy II. Hierarchical structure in the Pan-Andromeda Archaeological Survey Alan W. McConnachie,1 Rodrigo Ibata,2 Nicolas Martin,2 Annette M. N. Ferguson,3 Michelle Collins,4 Stephen Gwyn,1 Mike Irwin,5 Geraint F. Lewis,6 A. Dougal Mackey,7 Tim Davidge,1 Veronica Arias,8,6 Anthony Conn,6 Patrick Cotˆ e,´ 1 Denija Crnojevic,9 Avon Huxor,10 Jorge Penarrubia,3 Chelsea Spengler,11 Nial Tanvir,12 David Valls-Gabaud,13 Arif Babul,11 Pauline Barmby,14 Nicholas F. Bate,5,6 Edouard Bernard,15 Scott Chapman,16 Aaron Dotter,17 William Harris,18 Brendan McMonigal,6 Julio Navarro,11 Thomas H. Puzia,19 R. Michael Rich,20 Guillaume Thomas,1 and Lawrence M. Widrow21 1NRC Herzberg Astronomy and Astrophysics, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria, B.C., V9E 2E7, Canada 2Universit´ede Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France 3Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK 4Department of Physics, University of Surrey, Guildford, GU2 7XH, Surrey, UK 5Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK 6Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, Sydney, NSW 2006, Australia 7Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 8Departamento de F´ısica, Universidad de los
    [Show full text]
  • The Satellites and Stellar Halos of Nearby Milky Way-Mass Galaxies
    The Satellites and Stellar Halos of Nearby Milky Way-Mass Galaxies by Adam James Smercina A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Astronomy and Astrophysics) in The University of Michigan 2020 Doctoral Committee: Professor Eric F. Bell, Chair Associate Professor Jeremy Bailin Professor David Gerdes Professor Mario Mateo Professor John-David T. Smith Research Professor Monica Valluri Deer Mountain, RMNP Adam Smercina [email protected] ORCID iD: 0000-0003-2599-7524 © Adam Smercina 2020 All Rights Reserved For Darian, my love and greatest friend. ii ACKNOWLEDGEMENTS This dissertation would not have been possible without the love and support of a number of very special people. I first want to thank my Mom and Dad. Throughout my formative years, you always encouraged me to ask questions | like: \how does Davis{Besse work?" (Davis{Besse is the local nuclear plant in Ottawa County, OH) | and think creatively. Whether I was interested in dinosaurs or LEGOs, you al- ways provided me a space to grow and find myself. This encouragement and support ultimately fueled my creative spirit, my quest for greater knowledge, and my drive to follow my dreams. You have also continued to support me with unending enthusiasm through these later years, most importantly throughout my graduate career at Michi- gan. Whether it be driving to Ann Arbor and meeting for dinner or downloading and reading my papers as soon as they showed up on the arXiv (after learning what the arXiv was), you have remained constant pillars of support and joy in my life.
    [Show full text]