Front Matter

Cambridge University Press 978-0-521-62062-8 - The Multiwavelength Atlas of Galaxies Glen Mackie Frontmatter More information

The Multiwavelength Atlas of Galaxies

Since the radio signature of our own Milky Way was detected in 1931, galaxies have been observed from ultra-high-energy gamma rays to long-wavelength radio waves, providing funda- mental insights into their formation, evolution and structural components. Unveiling the secrets of some of the best-observed galaxies, this atlas contains over 250 full-color images spanning the whole electromagnetic spectrum. The accompanying text explains why we see the component stars, gas and dust through different radiation processes, and describes the telescopes and instruments used. This atlas is a valuable reference resource on galaxies for students seeking an overview of multiwavelength observations and what they tell us, and for researchers needing detailed summaries of individual galaxies. An accompay- ing website, hosted by the author, contains slide shows of the galaxies covered in this book. This is available at www.cambridge.org/9780521620628. Glen Mackie is a Lecturer in the Centre for Astrophysics and Supercomputing and Assistant Coordinator of Swin- burne Astronomy Online (SAO) at Swinburne University of Technology. His research interests include galaxy formation and evolution in the rich cluster environment, multiwavelength properties of galaxies, galaxy interactions and mergers, astronomy education and history.

The Multiwavelength Atlas of Galaxies

Glen Mackie Swinburne University of Technology

CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, Sao˜ Paulo, Delhi, Dubai, Tokyo, Mexico City

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c G. Mackie 2011

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First published 2011

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Library of Congress Cataloging-in-Publication Data

Mackie, Glen H., 1961– The multiwavelength atlas of galaxies / Glen H. Mackie. p. cm. ISBN 978-0-521-62062-8 (Hardback) 1. Galaxies–Atlases. 2. Galaxies–Observations. I. Title. QB856.M33 2010 523.112–dc22 2010033387

ISBN 978-0-521-62062-8 Hardback

Additional resources for this publication at www.cambridge.org/9780521620628

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For Corinne, with love. She outshines even these brilliant galaxies.

Contents

Preface page ix 2.4.6 Submillimeter 40 Acknowledgements xi 2.4.7 Radio 41 2.5 Caveat #1: Mass versus light and dark matter 43 2.6 Caveat #2: Looking back to the beginning 45 Galaxies 1 1 2.7 Caveat #3: Observational bias 48 1.1 Prehistory of galaxies 2 2.8 Galaxy research and multiwavelength 49 1.2 “It is worthy of notice” 5 observations 2.8.1 A unified scheme of active galaxies 49 1.3 Multiwavelength laboratories in space 6 2.8.2 The far-IR radio correlation 50 1.4 The atlas galaxy sample 9 2.8.3 A non-universal IMF 51 1.5 Atlas galaxy categories 9 2.8.4 Gamma ray bursts 51 1.5.1 Normal galaxies 9 2.8.5 Magnetic fields in galaxies 51 1.5.2 Interacting galaxies 9 2.9 Additional reading 53 1.5.3 Merging galaxies 11 1.5.4 Starburst galaxies 11 1.5.5 Active galaxies 12 3 A view from the inside: The Galaxy 55 1.6 Properties of the atlas sample 16 ∗ 1.6.1 Galaxy nomenclature 16 3.1 Quiet monster – Sagittarius A 55 1.6.2 Galaxy morphology 16 3.2 All-sky maps of the Galaxy 58 1.6.3 Distances and luminosities 22 3.2.1 Gamma ray – >100 MeV 58 1.6.4 Multiple classifications 23 3.2.2 Gamma ray – 1.8 MeV 58 1.7 Epoch of formation and galaxy ages 25 3.2.3 Soft X-ray 60 3.2.4 Optical 60 1.8 Additional reading 27 3.2.5 Optical – Hα at 6563 A˚ 60 3.2.6 Near-infrared 60 Observing the electromagnetic 3.2.7 Mid- and far-infrared 60 spectrum 29 2 3.2.8 Radio – molecular hydrogen 65 2.1 Earth’s atmosphere and extraneous radiation 29 3.2.9 Radio – atomic hydrogen 65 3.2.10 Radio – 73 cm/408 MHz continuum 65 2.2 Temperature, energy, wavelength 30 and frequency 3.3 Additional reading 65 2.3 Astronomical sources of radiation 33 2.4 Origin of astronomical radiation 33 4 The Atlas 67 2.4.1 Gamma rays 33 2.4.2 X-rays 35 4.1 Normal galaxies 68 2.4.3 Ultraviolet 37 4.1.1 NGC 224/Messier 31 68 2.4.4 Optical 37 4.1.2 Small Magellanic Cloud 75 2.4.5 Infrared 40 4.1.3 NGC 300 78

VIII CONTENTS

4.1.4 NGC 598/Messier 33 82 4.5.5 3C 273 186 4.1.5 NGC 891 90 4.5.6 NGC 4486/Messier 87 188 4.1.6 NGC 1399 94 4.5.7 NGC 4594/Messier 104 193 4.1.7 Large Magellanic Cloud 98 4.5.8 NGC 5128 197 4.1.8 NGC 2915 105 4.5.9 A1795 #1 206 4.1.9 Malin 2 108 4.5.10 Arp 220 209 4.1.10 NGC 5457/Messier 101 110 4.5.11 Cygnus A 212 4.1.11 NGC 6822 116 4.2 Interacting galaxies 119 Appendices and references 219 4.2.1 NGC 4406/Messier 86 119 4.2.2 NGC 4472/Messier 49 122 Appendix A: Telescopes and instruments 220 4.2.3 NGC 4676 124 Appendix B: Source list of all-sky Galaxy images 223 4.2.4 NGC 5194/Messier 51 127 Appendix C: Source list of galaxy images 224 4.3 Merging galaxies 135 4.3.1 NGC 520 135 Appendix D: Cross-reference list 234 4.3.2 NGC 1275 138 Appendix E: Common abbreviations 236 4.3.3 NGC 1316 141 and acronyms 4.3.4 NGC 4038/NGC 4039 146 Appendix F: Astronomical constants and units 237 4.3.5 NGC 7252 151 Appendix G: Other atlases of galaxies 237 4.4 Starburst galaxies 154 Appendix H: Spectral energy distributions 238 4.4.1 NGC 253 154 4.4.2 NGC 3034/Messier 82 161 General text references 240 4.4.3 NGC 5236/Messier 83 165 Major image sources and references 242 4.5 Active galaxies 171 Selected references by galaxy 243 4.5.1 NGC 1068/Messier 77 171 4.5.2 NGC 1365 174 Acknowledgements and permissions 250 4.5.3 NGC 3031/Messier 81 177 Galaxy index 252 4.5.4 NGC 4258/Messier 106 182 Index 253

Preface

In the early 1930s Karl Jansky1 detected the center of right. Almost overnight, the true nature of the Universe our Galaxy in radio waves at a wavelength of 14.6 m or a was discovered. Our Galaxy was one of billions. frequency of 20.5 MHz. Since Jansky’s breakthrough in the early 1930s Until this time all observations of galaxies had been astronomers interested in studying the formation and made in the optical region, which has radiation with evolution of galaxies have rapidly ventured into other wavelengths between 330 and 800 nanometers. Galaxies regions of the electromagnetic spectrum. In 1951 Ewen that can be seen by eye, appearing as faint, cloud-like and Purcell discovered 21 cm radio emission from inter- objects, are the two Magellanic Clouds (named after the stellar hydrogen, as predicted by Van de Hulst in 1945. Portuguese explorer Ferdinand Magellan) in the south- In 1961 the satellite Explorer 11 detected 22 events ern hemisphere and the Andromeda Galaxy (NGC 224 from high-energy gamma rays (and 22,000 events due or Messier 31) in the northern hemisphere. Observers to charged cosmic rays!). The first extrasolar X-ray with very good eyesight may also detect NGC 598/M 33, source was detected in 1962, using a sounding rocket, in the constellation Triangulum. We also get a myopic by the X-ray astronomy group at American Science view of nearby stars (about 6000 within a few thousand and Engineering. In the late 1960s Neugebauer and light-years) and a wide-field view of diffuse light, “the Leighton completed the first major near-infrared survey Milky Way”, from distant stars, near the plane of our of the sky. From 1968 onwards Orbiting Astronomical own Galaxy. Observatory (OAO) satellites provided the first detec- Since the early seventeenth century, telescopes have tions of sources in the ultraviolet. In 1987 the James provided higher resolution observations to fainter bright- Clerk Maxwell Telescope (JCMT) began dedicated obser- ness levels than possible with the eye. In 2009 the world vations in the submillimeter region. The optical and celebrated the International Year of Astronomy (IYA), near-infrared regions have also benefited by advances as sanctioned by the United Nations and directed by in instrumentation and active and adaptive optics on the the International Astronomical Union partly to celebrate latest generation of very large ground-based telescopes. 400 years of telescopic observations since the initial Near-diffraction-limited observing has been achieved by endeavors of Thomas Harriot and Galileo Galilei. placing telescopes above the Earth’s atmosphere (e.g. In terms of effective galaxy research tools, we had the Hubble Space Telescope since 1990). to wait until the mid-nineteenth century for large tele- Radiation from all regions of the electromagnetic scopes to be built. Observations by eye, photography and spectrum has now been detected from galaxies. These by spectroscopy all played vital roles. The Andromeda observations have utilized telescopes at ground-based Galaxy, and others, became known as “spiral nebulae” observatories (many located at high-altitude mountain and came under close scrutiny. The nature and con- sites), telescopes in aircraft (>10 km altitude), detec- tent of the spiral nebulae were increasingly debated tors on balloons that voyaged to the upper atmosphere until the mid-1920s when their true distances were (30–40 km altitude), instrument payloads on rockets that revealed. The spiral nebulae were not part of our reached space, observatory satellites in Earth and solar Galaxy, which many had thought constituted the Uni- orbit, as well as instruments aboard planetary missions verse. They were separate, distant galaxies in their own journeying through the Solar System.

1 K.G. Jansky, 1933, Electrical disturbances apparently of extraterrestrial origin, Proceedings of the IRE, 21, 1387; K.G. Jansky, 1933, Radio waves from outside the solar system, Nature, 132, 66.

X PREFACE

This atlas is a compendium of galaxy images span- descriptions from the literature. The book concludes ning the gamma ray, X-ray, ultraviolet, optical, infrared, (page 219) with appendices describing telescopes and submillimeter and radio regions of the electromagnetic instruments, image sources, technical descriptions of spectrum. Explanatory text describes how different radi- each image, a cross-reference list of galaxies, and ation is produced, which objects (i.e. cold, warm or example plots of spectral energy distributions. Gen- hot gas, dust, stars, particles, atoms and molecules) it eral text references and atlas galaxy references are also originates from, and what types of telescopes are used given. to detect it. The galaxies are divided into categories The images presented will help the general reader of normal, interacting, merging, starburst and active, appreciate the incredible information content of mul- though many have been classified across one or more tiwavelength observations without needing an extensive categories. scientific or mathematical background. The accom- The purpose of this atlas is to display and describe panying text provides specific discussion of galaxy some of the best multiwavelength images of galaxies. properties, and astronomical radiation origins and pro- The images originate from a variety of telescopes, instru- cesses useful for those wanting more astrophysics ments and detectors, and therefore possess wide ranges content. Research summaries of individual atlas galax- of signal-to-noise,2 angular resolution, sampling or pixel ies are given for those interested in more detailed sizes and fields of view. multiwavelength information. The atlas consists of four parts. The first part intro- An accompanying website duces galaxies, discusses the atlas sample, categories of http://astronomy.swin.edu.au/∼gmackie/MAG galaxies and properties of the sample. Part 2 (page 29) exists. I would appreciate correspondence from resear- describes the various origins of radiation emitted by chers who may have relevant information and/or images. galaxies and presents some important galaxy research topics that use multiwavelength observations. Part 3 Glen Mackie, (page 55) discusses multiwavelength radiation from the [email protected], Galactic center and finishes with all-sky multiwave- Centre for Astrophysics and Supercomputing, length images of our Galaxy. Part 4 (page 67) com- Swinburne University of Technology, prises the multiwavelength atlas images with scientific December, 2009, IYA

2 Signal-to-noise is a measure of the amount of detected radiation from a source above the inherent radiation or noise of the detector and background signal.

Acknowledgements

This atlas has come about due to the generosity of images of the Galaxy and reformatting several images. many astronomers that have kindly provided their data Karen Smale (LHEA), Kathy Lestition (Chandra X-ray and information about their observations. I would like Observatory Center), Dan Brocious (Smithsonian Insti- to thank P. Amram, P. Barthel, R. Beck, L. Blitz, M. tution, Whipple Observatory), Catherine Ishida (Subaru Birkinshaw, G. Bothun, G. Bower, A. Bridle, U. Briel, E. Telescope) and support staff at STScI helped with my Brinks, M. Burton, H. Bushouse, B. Canzian, C. Carilli, J. many enquiries. I worked on the beginnings of this Chapman, P. Choi, J. Condon, P. Cox, P. Crane, T. Dame, atlas whilst visiting the Anglo-Australian Observatory R. Diehl, S. Digel, S. Do¨bereiner, M. Dopita, N. Duric, E. and I thank the then Director, Prof. Brian Boyle, for his Dwek, M. Ehle, G. Fabbiano, E. Feigelson, L. Ferrarese, hospitality. D. Finkbeiner, K. Freeman, P. Guhathakurta, R. Genzel, I would also like to thank the editorial staff at Cam- M. Haas, D. Hartmann, R. Haynes, D. Heeschen, J. bridge University Press, especially Adam Black for his P. Henry, J. Hibbard, H. Hippelein, S. Holmes, J. C. initial interest in the atlas, and Vince Higgs and Lindsay Howk, J. Holtzman, Hubble Heritage Team, A. Hughes, E. Barnes for their expert guidance to get it to completion. Hummel, J. Hutchings, G. Jacoby, S. Jorsater, N. Junkes, The construction (construction tends to more ade- P. Kahabka, J. Kamphuis, W. Keel, D. Kelly, N. Killeen, U. quately describe the process of producing this atlas than Klein, B. Koribalski, K. Kraemer, M. Kramer, M. Krause, writing!) and presentation of this work were greatly R. Laing, S. Larsen, D. Leisawitz, G. Lewis, L. Lindegren, improved due to the keen eye of my wife, Corinne. She Local Group Survey Team, B. Madore, P. Massey, A. quizzed me on many statements during enthusiastic read- Mattingly, D. Maoz, A. Marlowe, A. McConnachie, S. ings of the chapters. I thank her for wonderful support McGaugh, K. McLeod, MCELS Team, D. Meier, K. M. and encouragement. Merrill, G. Meurer, C. Mundell, N. Neininger, R. Norris, I hope this atlas represents a tribute to the rapid U. Oberlack, K. Olsen, A. Pedlar, R. Perley, W. Pietsch, J. progress made in multiwavelength observations of galax- Pinkney, P. Planesas, R. Pogge, S. Points, M. Putman, R. ies and credit is due to all astronomers involved in Rand, S. Raychaudhury, T. Rector, M. Regan, W. Rice, G. this type of research. It was always heartening to hear Rieke, M. Rieke, A. Rots, M. Rubio, S. Ryder, B. Savage, E. support from astronomers who corresponded with me Seaquist, E. Schlegel, S. Schoofs, N. Scoville, E. Shaya, S. about the atlas during its construction, and who were Shostak, C. Smith, S. Snowden, W. Sparks, S. A. Stanford, extremely generous with their time and knowledge: L. Staveley-Smith, R. Supper, R. Sutherland, P.Thaddeus, many thanks to Rainer Beck, John Hibbard, Annie R. Tilanus, S. Tingay, G. Trinchieri, J. Trumper,¨ B. Tully, J. Hughes, Phil Massey, and Sean Points. Turner, J. Ulvestad, E. Valentijn, J. van der Hulst, G. van I received valuable comments on drafts of this atlas Moorsel, L. Vigroux, A. Vogler, W. Walsh, R. Walterbos, from astronomers Chris Flynn, Virginia Kilborn, Bill B. Whitmore, R. Wielebinski, A. Wilson, F. Winkler, T. Keel, Malcolm Longair, Emma Ryan-Weber and Steve Wong, J. Wrobel, C. M. Young, and H. Zimmermann. Tingay which greatly improved the ﬁnal product. I have Credits for atlas image observers and data owners are also beneﬁted from comments from anonymous referees also summarized in Appendix C (page 224). appointed by Cambridge University Press. Any errors or Seth Digel (GSFC) was of great assistance in pro- omissions remaining are entirely my responsibility. viding many of the Astrophysics Data Facility all-sky G.M.