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Cambridge University Press 978-1-107-02380-2 - Local Group Cosmology Edited by David Martínez-Delgado Frontmatter More information

LOCAL GROUP COSMOLOGY

One of the most fascinating unresolved problems of modern astrophysics is how the galaxies we observe today were formed. The Lambda–Cold Dark Matter paradigm predicts that large spiral galaxies such as the Milky Way formed through accretion and tidal disruption of satellite galaxies, a notion previously postulated on empirical grounds from the character of stellar populations found in our Galaxy. The Local Group galaxies are the best laboratory in which to investigate these galaxy formation processes because they can be studied with suﬃciently high resolution to exhume fossils of galactic evolution embedded in the spatial distribution, kinematics, and chemical abundances of their oldest stars. Based on the twentieth Canary Island Winter School of Astrophysics, this volume provides a ﬁrm grounding for graduate students and early career researchers working on Local Group cosmology. It presents modules from seven eminent and experienced scientists at the forefront of Local Group research, and includes overviews of observational techniques, diagnostic tools, and various theoretical models.

David Mart´ınez-Delgado is an astronomer at the Max-Planck Institute for Astronomy, Heidelberg, Germany, and at the Instituto de Astrof´ısica de Canarias, Spain.

Canary Islands Winter School of Astrophysics

Volume XX Series Editor Francisco S´anchez, Instituto de Astrof´ısica de Canarias

Previous books in this series

I. Solar Physics II. Physical and Observational Cosmology III. Star Formation in Stellar Systems IV. Infrared Astronomy V. The Formation of Galaxies VI. The Structure of the Sun VII. Instrumentation for Large Telescopes: A Course for Astronomers VIII. Stellar Astrophysics for the Local Group: A First Step to the Universe IX. Astrophysics with Large Databases in the Internet Age X. Globular Clusters XI. Galaxies at High Redshift XII. Astrophysical Spectropolarimetry XIII. Cosmochemistry: The Melting Pot of Elements XIV. Dark Matter and Dark Energy in the Universe XV. Payload and Mission Deﬁnition in Space Sciences XVI. Extrasolar Planets XVII. 3D Spectroscopy in Astronomy XVIII. The Emission-Line Universe XIX. The Cosmic Microwave Background: From Quantum Fluctuations to the Present Universe

Participants of the XX Canary Islands Winter School of Astrophysics

LOCAL GROUP COSMOLOGY

Edited by DAVID MART´INEZ-DELGADO

Max-Planck-Institut f¨ur Astronomie, Heidelberg

32 Avenue of the Americas, New York, NY 10013-2473, USA

Cambridge University Press is part of the University of Cambridge. It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning, and research at the highest international levels of excellence.

www.cambridge.org Information on this title: www.cambridge.org/9781107023802 c Cambridge University Press 2013 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2013 Printed in the United States of America A catalog record for this publication is available from the British Library. Library of Congress Cataloging in Publication data Canary Islands Winter School of Astrophysics (20th : 2008 : Tenerife, Canary Islands) Local Group cosmology / [edited by] David Mart´ınez-Delgado, Max-Planck-Institut f¨ur Astronomie, Heidelberg. pages cm Lectures presented at the XX Canary Islands Winter School of Astrophysics, held in Tenerife, Spain, November 17–18, 2008. Includes bibliographical references. ISBN 978-1-107-02380-2 (hardback) 1. Local Group (Astronomy) – Congresses. I. Mart´ınez Delgado, D. (David), editor of compilation. II. Title. QB858.8.L63C36 2008 523.112–dc23 2013012345 ISBN 978-1-107-02380-2 Hardback Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party Internet Web sites referred to in this publication and does not guarantee that any content on such Web sites is, or will remain, accurate or appropriate.

Contents

List of contributors page ix

List of participants xi

Preface xiii

Acknowledgments xv

Abbreviations xvii

1 The formation of the Milky Way in the CDM paradigm 1 K. C. Freeman

2 Dark matter content and tidal eﬀects in Local Group dwarf galaxies 47 Steven R. Majewski

3 Notes on the missing satellites problem 95 James Bullock

4 The Milky Way satellite galaxies as critical tests of contemporary cosmological theory 123 P. Kroupa

5 Stellar tidal streams 162 R. Ibata

6 Tutorial: The analysis of colour-magnitude diagrams 192 D. Valls-Gabaud

7 Tutorial: Modeling tidal streams using N-body simulations 226 J. Pe˜narrubia

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List of contributors

Bullock, James, University of California Irvine, USA Freeman, K. C., Australian National University, Australia Ibata, R., Strasbourg Observatory, France Kroupa, P., Angelander-Institut f¨ur Astronomie, Germany Majewski, Steven R., University of Virginia, USA Penarrubia,˜ J., Institute of Astronomy, University of Cambridge, UK Valls-Gabaud, D., Observatoire de Paris, France

List of participants

Alonso Garc´ıa, Javier University of Michigan – Department of Astronomy (United States of America) Antoja, Teresa Universitat de Barcelona – Institut de Ciències del Cosmos Department d’Astronomia i Meteorologia (Spain) Bakos, Judit Instituto de Astrof´ısica de Canarias (Spain) Beaton, Rachael University of Virginia (United States of America) Besla, Gurtina Harvard-Smithsonian Center for Astrophysics (United States of America) Bovill, Mia University of Maryland – Department of Astronomy (United States of America) Brink, Thomas University of Michigan – Department of Astronomy (United States of America) Carballo Bello, Julio Alberto Instituto de Astrof´ısica de Canarias (Spain) Carrera, Ricardo Osservatorio Astronomico di Bologna (Italy) Cheng, Judy UC Santa Cruz (United States of America) Comerón Limbourg, Sébastien Instituto de Astrof´ısica de Canarias (Spain) Conn, Blair European Southern Observatory (Chile) Correnti, Matteo Universitá degli studi di Bologna (Italy) Damke, Guillermo University of Virginia – Astronomy Building (United States of America) Ebrová, Ivana Academy of Sciences of the Czech Republic (Czech Republic) Ferré Mateu, Anna Instituto de Astrof´ısica de Canarias (Spain) Fliri, Jürgen Instituto de Astrof´ısica de Canarias (Spain) Guerras Valera, Eduardo Instituto de Astrof´ısica de Canarias (Spain) Hamden, Erika Columbia University and Astronomy Department (United States of America) Hayward, Chris Harvard-Smithsonian Center for Astrophysics (United States of America) Hummels, Cameron Columbia University and Astronomy Department (United States of America) Ibarra Medel, Héctor Javier Instituto Nacional de Astrof´ısica, Optica´ y Electrónica (Mexico) Kang, Aram University of Edinburgh – Institute of Astronomy (United Kingdom) Karlsson, Torgny University of Sidney – Institute of Astronomy (Australia) Kirby, Emma Research School of Astronomy and Astrophysics – Mt Stromlo Observatory (Australia) Klimentowski, Jaroslaw Nicolaus Copernicus Astronomical Center (Poland) Kordopatis, George Observatoire de la Cote d’Azur (France) Li, Yang-Shyang Kaptein Astronomical Institute (The Netherlands) Marks, Michael Argelander-Institut für Astronomie (Germany) Mateu, Cecilia Centro de Investigación de Astronom´ıa (Venezuela) Narbutis, Donatas University of Vilnius (Lithuania) Navarro González, Javier Instituto de Astrof´ısica de Canarias (Spain) Paudel, Sanjaya Astronomisches Rechen-Institut Zentrum für Astronomie (Germany)

xii List of participants Petrov, Mykola University of Vienna – Institute of Astronomy (Austria) Radburn-Smith, David STScI (United States of America) Rivero Losada, Illa Instituto de Astrof´ısica de Canarias (Spain) Rubele, Stefano Universita di Padova – Dipartimento di Astronomia (Italy) Ruhland, Christine Max-Planck Institut für Astronomie (Germany) Sale, Stuart Astrophysics Group Blackett Laboratory – Imperial College London (United Kingdom) Salinas, Ricardo European Southern Observatory (Chile) Sánchez Gallego, José Ramón Instituto de Astrof´ısica de Canarias (Spain) Simpson, Christine Columbia University (United States of America) Sollima, Antonio Instituto de Astrof´ısica de Canarias (Spain) Starkenburg, Else Kapteyn Astronomical Institute (The Netherlands) Tapia Peralta, Trinidad Instituto de Astrof´ısica de Canarias (Spain) Tempel, Elmo Tartu Observatory (Estonia) Teyssier, Maureen Columbia University Astronomy Department (United States of America) Tikhonov, Anton Sobolev Astronomical Institute, Saint-Petersburg State University – Department of Mathematics and Mechanics (Russia) Valentini, Marica Universita di Padova (Italy)

Preface

Background One of the unresolved problems of modern astrophysics is how the galaxies we observe today were formed. The Lambda–Cold Dark Matter paradigm predicts that large spiral galaxies like the Milky Way formed through the accretion and tidal disruption of satellite galaxies, a notion previously postulated on empirical grounds from the character of stellar populations found in our Galaxy. The Local Group galaxies are the best laboratory in which to investigate these galaxy formation processes as they can be studied with suﬃciently high resolution to exhume the fossils of galactic evolution embedded in the spatial distribution, kinematics, and chemical abundances of their oldest stars.

Scientific rationale This “Galactic archaeology” has recently undergone an unprecedented revolution, brought about by the spectacular increase in the quality and quantity of observations of Local Group galaxies using large-aperture ground-based telescopes and the Hubble Space Telescope, and with the advent of the first large-scale digital sky surveys (such as SLOAN and 2MASS) at the start of the twenty-first century. The possibility of contrasting these observations with results on a small scale of cosmological simulations has drawn the attention of cosmologists towards the study of Local Group grand design galaxies and their satellites, thus giving rise to new lines of research that have involved numerous resources and a considerable observational and theoretical effort. The disagreement between the results of simulations and observations has also given rise to serious controversies among observers and theoretical cosmologists and is still the subject of active debate in the international community. There is little doubt that the “golden age” of these investigations will take place in the coming years with the commissioning of ambitious observational projects such as the LSST (Large Synoptic Survey Telescope) in Chile or the launching of the astrometric satellite GAIA. These projects will constitute an enormous qualitative and quantitative leap in data and will require the training of young researchers in a field that has hitherto been the object of study for a relatively small number of scientists. Recognizing the importance of this field, the Instituto de Astrof´ısica de Canarias organized the XXth in its Winter School series around the topic “Local Group Cosmology.”

Outline of the school The primary aim of the school was to provide a wide-ranging and up-to-date overview of the theoretical, experimental, and analytical tools necessary for carrying out front- line research in the study of the structure, formation, and evolution of Local Group galaxies, based on the results of the latest cosmological simulations. The Winter School was particularly designed to oﬀer young researchers tips and guidelines to help them direct their future research toward these themes, which are among the most important in modern astrophysics. With this purpose, the school provided to the participants an introduction to the physics of the Local Group galaxies, observational techniques, diagnostic tools, and theoretical codes. In addition, the existing and planned experiments and surveys were reviewed with a description of the analysis methods involved and the constraints imposed on theoretical models. This was complemented by an overview of galactic and extragalac- tic foregrounds, as well as a summary of other major cosmological probes. To achieve these goals, the 40 lectures were given by eight eminent and experienced scientists who are actively working on a variety of forefront research projects and who xiii

xiv Preface have played a key role in major advances over recent years in the topic of the school. The list of teachers included leading cosmologists and pioneering observers in each area of the subject who were carefully chosen to represent all the leading research teams in each topic covered in the school, especially those topics where there is disagreement among the diﬀerent teams.

The Editor

Acknowledgments

The organizers of the XX Canary Islands Winter School of Astrophysics would like to express their sincere gratitude, first and foremost, to the lecturers, for making it a great scientific and educational event. The careful preparation of the lectures, the attendance and intense interaction with students, and the subsequent writing up of the manuscripts for this book have been a major commitment in their busy agendas. In particular, we would like to thank Professor Ken Freeman for his entertaining public lecture on “Dark Matter in Galaxies.” The students played an important role in the success of the Winter School: their enormous enthusiasm − maintained throughout the entire two weeks − and outstanding human quality resulted in a really pleasant and fruitful event. The editor wants to express his warmest gratitude to the efficient secretaries, Nieves Villoslada and Lourdes González. Their great knowledge and diligence before, during, and after the Winter School are a key component in its success. The Web page of the Winter School was a vital tool in the preparation and development of the event, and we thank Jorge Andrés Pérez (SIE/IAC) for its care and maintenance. The press room of the Winter School was the responsibility of Nadjejda Vicente and Iván Jiménez, who did a wonderful job interviewing the lecturers. Ramon Castro and Gabriel Pérez (SMM/IAC) designed the posters and additional multimedia support material for the Winter School. Ismael Mart´ınez-Delgado played a major part in the creation of this book, revising in minute detail and with enormous patience and technical editorial skill all the submitted manuscripts. Each year, the Canary Island Winter School of Astrophysics is a major institutional event at the IAC, whose various departments and support services always actively and enthusiastically contribute to it: Jesús Burgos, Carmen del Puerto, Terry Mahoney, Julio A. Carballo-Bello, Miguel Briganti, Monique Gómez and the technicians of the Servicios Informáticos Comunes (SIC) of the IAC. We thank all concerned for their support and efficiency. We also thank the respective managers and guides who made possible the visits to the Observatories on Tenerife and La Palma. Finally, we also wish to thank Spain’s Ministerio de Ciencia e Innovación, the local governments (Cabildos) of the islands of Tenerife and La Palma, the Puerto de la Cruz Council, and Iberia for their economical support to the organization of this Winter School.

The Editor

Abbreviations

2MASS Two Micron All Sky Survey AAT Anglo Australian Telescope AGB Asymptotic Giant Branch APOD Astronomy Picture of the Day APOGEE Apache Point Observatory Galactic Evolution Experiment CCD Charge Coupled Device CCI Central Credible Interval CDM Cold Dark Matter CDMS Cryogenic Dark Matter Search CMB Cosmic Microwave Background CMD Color Magnitude Diagram CMSSM Constrained Minimal Supersymmetric Standard Model COBE COsmic Background Explorer COROT COnvection ROtation and Planetary Transits CPU Central Processing Unit CR Credible Region dE dwarf Elliptical DES Dark Energy Survey DIRBE Diffuse Infrared Background Experiment DM Dark Matter DoS Disk of Satellites dSph dwarf Spheroidal ESA European Space Agency ESO European Southern Observatory FLAMES Fibre Large Array Multi-Element Spectrograph FWHM Full Width at High Maximum GR General Theory of Relativity GSC Guide Star Catalog HDM Hot Dark Matter HERMES High Efficiency and Resolution Multi-Element Spectrograph HRD Hertzsprung-Russell Diagram HSB High Surface Brightness HST Hubble Space Telescope IMF Initial Mass Function IPAC Infrared Processing and Analysis Center JASMINE Japan Astrometry Satellite Mission for INfrared Exploration LAB Leiden Argentine Bonn LG Local Group LMC Large Magellanic Cloud LSB Low Surface Brightness LSR Local Standard of Rest LSST Large Synoptic Survey Telescope MCI Minimum Credible Interval MFL Mass Follows Light MIKE Magellan Inamori Kyocera Echelle MLT Mixing Length Convection Theory MMT Multi Mirror Telescope MOG MOdified Gravity MOND MOdified Newtonian Dynamics

xvii

xviii Abbreviations MOS Multi-Object Spectroscopy MOST Microvariability and Oscillations of Stars Telescope MS Magellanic Stream MS Main Sequence MSP Missing Satellites Problem MW Milky Way NASA National Aeronautics and Space Administration NFW Navarro-Frenk-White OLR Outer Lindblad Resonance PAndAS Pan-Andromeda Archeological Survey Pan-STARRS Panoramic Survey Telescope & Rapid Response System PDF Probability Distribution Function PM2000 Bordeaux Proper Motion Catalogue RAVE RAdial Velocity Experiment RGB Red Giant Branch RHR Rosenberg-Hertzsprung-Russell Diagram RMS Root Mean Square SAM Semi Analytical Modelling SDSS Sloan Digital Sky Survey SEGUE Sloan Extension for Galactic Understanding and Exploration SEHO South-East H I Overdensity SFH Star-Formation History SFR Star-Formation Rate SMC Small Magellanic Cloud SNe Super Novae SPH Smoothed Particle Hydrodynamics SPM Southern Proper Motion STScI Space Telescope Science Institute TAMS Terminal Age Main Sequence TDG Tidal Dwarf Galaxies TO Turn-Oﬀ UCAC2 Second USNO CCD Astrograph Catalogue UCD Ultra Compact Dwarf Galaxy UKIDSS UK Infrared Telescope Infrared Deep Sky Survey USNO United States Naval Observatory VHS Vista Hemisphere Survey VISTA Visible and Infrared Survey Telescope for Astronomy VL II Via Lactea II Simulation VLT Very Large Telescope WDLF White Dwarf Luminosity Function WDM Warm Dark Matter WIMP Weakly Interacting Mass Particle WMAP Wilkinson Microwave Anisotropy Probe ZAMS Zero Age Mass Sequence ΛCDM Dark Energy + Cold Dark Matter