Hot Interstellar Matter in Elliptical Galaxies For further volumes: http://www.springer.com/series/5664 Astrophysics and Space Science Library EDITORIAL BOARD Chairman W. B. BURTON, National Radio Astronomy Observatory, Charlottesville, Virginia, U.S.A. ([email protected]); University of Leiden, The Netherlands ([email protected]) F. BERTOLA, University of Padua, Italy J. P. CASSINELLI, University of Wisconsin, Madison, U.S.A. C. J. CESARSKY, Commission for Atomic Energy, Saclay, France P. EHRENFREUND, Leiden University, The Netherlands O. ENGVOLD, University of Oslo, Norway A. HECK, Strasbourg Astronomical Observatory, France E. P. J. VAN DEN HEUVEL, University of Amsterdam, The Netherlands V. M. KASPI, McGill University, Montreal, Canada J. M. E. KUIJPERS, University of Nijmegen, The Netherlands H. VAN DER LAAN, University of Utrecht, The Netherlands P. G. MURDIN, Institute of Astronomy, Cambridge, UK F. PACINI, Istituto Astronomia Arcetri, Firenze, Italy V. RADHAKRISHNAN, Raman Research Institute, Bangalore, India B . V. S O M OV, Astronomical Institute, Moscow State University, Russia R. A. SUNYAEV, Space Research Institute, Moscow, Russia Dong-Woo Kim Silvia Pellegrini Editors Hot Interstellar Matter in Elliptical Galaxies 123 Editors Dong-Woo Kim Harvard Smithsonian Center for Astrophysics Garden Street 60 02138 Cambridge Massachusetts USA [email protected] Silvia Pellegrini Dipartimento di Astronomia Universita` di Bologna Via Ranzani 1 40127 Bologna Italy [email protected] Cover figure: Chandra image of NGC 7619. From Kim et al. (2008). Reproduced by permission of the AAS. ISSN 0067-0057 ISBN 978-1-4614-0579-5 e-ISBN 978-1-4614-0580-1 DOI 10.1007/978-1-4614-0580-1 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2011938147 c Springer Science+Business Media, LLC 2012 This work is subject to copyright. 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Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preface The physical properties of the hot interstellar matter (ISM) in elliptical galaxies are directly related to the formation and evolution of these systems, via star formation episodes, the passive evolution of their aging stellar population, environmental effects such as stripping, infall, and mergers, and the growth of supermassive black holes. The recent successful X-ray space missions Chandra and XMM-Newton have provided a large amount of unprecedented high quality observational data on the hot ISM in elliptical galaxies. Thanks to the outstanding angular resolution of Chandra and the large collecting area of XMM-Newton, the fine structure of the hot gas has been imaged in detail, and key physical quantities have been accurately measured, so that theoretical predictions can be compared and tested against the observational results. At the same time, theoretical studies with numerical simulations and analytical modeling of the dynamical and chemical evolution of elliptical galaxies and their hot gas have made significant progress, and start to predict various observable quantities. With contributions from eight leading experts in this field, we intend in this book to review the most significant improvements to our understanding of the hot ISM in elliptical galaxies, and present in detail a number of key discoveries obtained during the last 10 years of the Chandra and XMM-Newton missions, and the corresponding theoretical work. The need for this book originally emerged during the Joint Discussion between the “Galaxies” and “ISM” IAU Divisions, organized for the XXVII IAU General Assembly of 2009 in Brazil; upon this occasion both observers and theorists in the field were brought together to identify important, but unsolved problems for further investigation, with special emphasis on the spectral and spatial properties of the hot ISM and the comparison with recent theoretical models. Throughout this Joint Discussion, it became clear that time was ripe for an extensive publication, covering a large amount of new important material, and acting as a useful reference for students who approach this field, as well as for experts in related fields. As this book is primarily intended for graduate students and non-specialists, we provide first in each chapter an introductory and historical background, fol- lowed by state-of-the-art results, with a special emphasis on the balance between v vi Preface observational and theoretical aspects. Throughout the book, the chapters are arranged in such a way that the observational and theoretical results can be compared side by side. Among the eight chapters, roughly half are observationally oriented and the other half are theoretically oriented. All chapters are cross- referenced whenever necessary, so that the readers can easily overview and grasp a coherent picture by finding the related materials discussed in the different parts of the book. By nature of the state-of-the-art science that is continuously advanced through arguing and counter-arguing, there may be occasionally differing views on an issue, and this is the case for the last two chapters of the book. While we try to minimize any potential confusion, conflicting views are unavoidable sometimes, so the two different positions are presented as they are, and we ask the readers to carefully consider the arguments of both. We hope that this case provides an excellent example for the students to start building their own research framework for their solid future. Cambridge Dong-Woo Kim Bologna Silvia Pellegrini Contents 1 The Hot ISM of Elliptical Galaxies: A Brief History .................... 1 Giuseppina Fabbiano 2 Hot Gas Flows on Global and Nuclear Galactic Scales .................. 21 Silvia Pellegrini 3 Feedback and Environmental Effects in Elliptical Galaxies ............ 55 Craig L. Sarazin 4 AGN Feedback in Elliptical Galaxies: Numerical Simulations ......... 83 Luca Ciotti and Jeremiah P. Ostriker 5 Metal Abundances in the Hot ISM of Elliptical Galaxies ............... 121 Dong-Woo Kim 6 Abundances and Abundance Ratios in Stars and Hot Gas in Elliptical Galaxies ......................................................... 163 Antonio Pipino 7 Hot Gas Morphology, Thermal Structure, and the AGN Connection in Normal Elliptical Galaxies ....................................................................... 207 Thomas S. Statler 8 Dark Matter in Elliptical Galaxies ......................................... 235 David A. Buote and Philip J. Humphrey Index ............................................................................... 279 vii Chapter 1 The Hot ISM of Elliptical Galaxies: A Brief History Giuseppina Fabbiano This chapter reviews the history of the discovery of a hot gaseous interstellar medium (ISM) in normal E and S0 galaxies with the imaging X-ray telescope of the Einstein Observatory. It also highlights the ensuing two-decade long debate on the ubiquity and properties of this medium, and on the suitability of X-ray observations for measuring the gravitational mass of early-type galaxies. Fundamental questions explored during this period included: How much of the X-ray emission is truly from a hot ISM? Is this ISM in hydrostatic equilibrium? Can the data constrain the physical and chemical evolution of this hot medium? While the debate went on, a deeper understanding on the evolution of the hot ISM was generated. Some of these outstanding questions have now been solved with the high spatial resolution observations of the Chandra X-ray Observatory and with the high signal-to-noise spectra of XMM-Newton. 1.1 X-ray Astronomy and the Discovery of Hot Gaseous Halos The first extended extragalactic X-ray sources were discovered early in the history of X-ray astronomy with the Uhuru satellite (Giacconi et al. 1971)intheVirgo (Kellogg et al. 1971)andComa(Gursky et al. 1971) clusters. These discoveries were extended soon after to several other galaxy clusters (e.g., Forman et al. 1972; Gursky et al. 1972; Kellogg and Murray 1974). Gursky et al. (1971) pointed out that the temperature of a hot gas derived from a fit to a bremsstrahlung model of the X-ray spectrum of the Coma cluster (73 106 K 7 keV), would give thermal velocities of 1;050 ˙ 90 km s1, comparable with the velocity dispersion of the galaxies in the cluster (1;470 km s1). Although observational confirmation that the diffuse emission was indeed the thermal emission of hot plasma had to await later G. Fabbiano () Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA D.-W. Kim and S. Pellegrini (eds.), Hot Interstellar Matter in Elliptical Galaxies, 1 Astrophysics and Space Science Library 378, DOI 10.1007/978-1-4614-0580-1 1, © Smithsonian Institution