Santa Cruz Summer Workshops in Astronomy and Astrophysics S.M. Faber Editor Nearly Nonnal Galaxies From the Planck Time to the Present The Eighth Santa Cruz Summer Workshop in Astronomy and Astrophysies July 21-August 1, 1986, Liek Observatory With 133 Illustrations Springer-Verlag New York Berlin Heidelberg London Paris Tokyo S. M. Faber Department of Astronomy University of California Santa Cruz, CA 95064, USA Library of Congress Cataloging-in-Publication Data Santa Cruz Summer Workshop in Astronomy and Astrophysics (8th: 1986) Nearly normal galaxies. (Santa Cruz summer workshops in astrophysics) I. Galaxies-Congresses. 2. Astrophysics- Congresses. I. Faber, Sandra M. 11. Title. 111. Series. Q8856.S26 1986 523.1' 12 87-9559 © 1987 by Springer-Verlag New York Inc. Softcover reprint ofthe hardcover 1st edition 1987 All rights reserved. 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Permission to photocopy for internal or personal use, or the internal or personal use of specific c1ients, is granted by Springer-Verlag New York Inc. for libraries registered with the Copyright Clearance Center (CCC), provided that the base fee of $0.00 per copy, plus $0.20 per page is paid directly to CCC, 21 Congress Street, Salem, MA 01970. U.S.A. Special requests should be addressed directly to Springer-Verlag New York, 175 Fifth Avenue, New York, New York 10010, U.S.A. 96521-1/1987 $0.00 + .20 987654321 ISBN-13:978-1-4612-9145-9 e-ISBN-13978-1-4612-4762-3 DOI: 10.1007/978-1-4612-4762-3 ALBERT EDWARD WHITFORD On October 22, 1985, Albert Whitford celebrated his eightieth birthday. Whitford is honored as one of the founding fathers of photoelectric photometry, the technique that transformed twentieth-century astronomy from a qualitative to a quantitative science. Together with collaborator and mentor Joel Stebbins, Whit­ ford began, in the early 1930s, a systematic survey of stellar and galaxy photometry that initiated the modern era of this subject. Concepts encountered in this early work included interstellar extinction, color excess, effective wavelengths, galaxy surface-brightness profiles, and K-corrections. Techniques developed by Whitford and Stebbins to deal with these have become such apart of the lore of observational astronomy that their origins to today's students are obscure. Whitford's own con­ tribut ion to this work lay principally in the perfection of the equipment, notably in low-noise amplification of the signal. Joining Stebbins as a junior collaborator and fresh Ph.D. (in physics from Wisconsin), Whitford exercised skills as an instru­ mentalist so outstanding that, within a short while, Stebbins came to regard hirn as indispensable. vi Albert Edward Whitford World War II intervened, and Whitford spent five years in war work at the MIT Radiation Laboratory. After the war, he returned to Washburn Observatory at Wisconsin, where he shortly became Director and Full Professor. In 1958 he moved west to become Director of the Liek Observatory. There his technieal acumen enabled hirn to take charge of the 120-inch telescope project when it was far behind schedule and get it rapidly back on track. Within little more than a year the telescope was in full operation and continues to this day as the mainstay of the optieal astronomy program of the University of California. At about this time Whitford wrote what is probably his most quoted paper setting forth a standard interstellar extinction curve, the so-called Whitford law. In the 1960s he was president of the Ameriean Astronomieal Society and chaired the first National Academy of Sciences review on the progress and needs of observa­ tional astronomy. Ground Based Astronomy: A Ten Year Program was so weil and wisely written that it became a model for N AS discipline reviews and has inspired two subsequent astronomie al reviews in a pattern that now threatens to become established custom. Rereading the Whitford Report, one finds that its recommen­ dations were closely followed and that its vision shaped the pattern for the technieal advancement of observational astronomy from the 19605 onward. In 1973, Albert Whitford became Emeritus Professor / Astronomer, but with retirement his scientific productivity if anything began to increase. In a pro­ fession renowned for the vigor of its older practitioners, Whiford's achievements after retirement inspire the greatest admiration. A major early impetus for the Stebbins-Whitford photoelectrie photometry program was an interest in galaxy stellar populations and in quantifying comparisons between galaxy spectral-energy Albert Edward Whitford Vll distributions and those of stars. In the 1970s Whitford realized that the nuclear bulge of the Galaxy provided a unique opportunity to study, star-by-star, a strong­ lined, old stellar population like that found in elliptical galaxies and spiral bulges. Since then, he and his collaborators Jay Frogel, Mike Rich, and Don Terndrup have been collecting fundamental data - colors, magnitudes, and spectra - of bulge stars. As in all great enterprises, this one has not been without its surprises, turning up giant branch stars that are simultaneously metal-rich but rather blue. The bulge studies are clearly yielding unique data on old stars of fundamental importance to population syntheses of external galaxies. In view of Whitford's age, it is not surprising that his recent collaborators are all younger than he, but it is significant that two of them - Rich and Terndrup - were graduate students. Albert Whitford seems to have had a special affinity for graduate students in his emeritus years. His office was and is a place students can go to find encouragement and a sympathetic ear. Several Lick students, including Alan Dressler, David Burstein, and Nick Suntzeff, remember Albert for the benign infiuence he has had on their graduate careers. In recognition of his lifetime of achievement in the areas of photoelectric photometry and galactic stellar populations, the first session of this year's Santa Cruz Workshop is enthusiastically dedicated to Albert Edward Whitford. S. M. Faber July 1986 Preface It is sometimes said that astronomy is the crossroads of physics. In the same spirit, it can forcefully be argued that galaxies are the crossroads of astronomy. Internal pro ces ses within galaxies involve all of the fundamental components of astrophysics: stellar evolution, star formation, low-density astrophysics, dynamics, hydrodynamics, and high-energy astrophysics. Indeed, one can hardly name an observational datum in any wavelength range on any kind of celestial object that does not provide a useful clue to galaxy formation and evolution. Although internal processes in galaxies until recently occupied most of our attention, we now know that it is also vital to relate galaxies to their environment. How galaxies congregate in larger structures and are in turn influenced by them are crucial questions for galactic evolution. On a grander level we have also come to regard galaxies as the basic building blocks of the universe, the basic units whereby the large­ scale structure of the universe is apprehended and quantified. On a grander level still, we also believe strongly that galaxies are the direct descendents of early density irregularities in the Big Bang. Galaxy properties are now viewed as providing a crucial constraint on the physics of the Big Bang and a vital link between the macroscopic and microscopic structure of the universe. A picture of galactic evolution as the crossroads of astronomy and cosmology thus emerges very strongly - a melding of basic physics and astrophysics, an eclectic borrowing of diverse observation al techniques, and the convergence of the very large with the very small. To understand galaxies in all their ramifications clearly entails a synthesis of the highest order. x Preface Such a synthesis was the avowed goal of this summer's Santa Cruz Summer Workshop on galaxies. The extended, two-week format allowed participants to cover essentially all of the major issues of current interest in galaxy formation and evolution - from stellar evolution to cosmic strings and virtually everything in between. It was the first time, to my knowledge, that an organized meeting of such long duration was devoted to the subject, and the result was a more comprehensive, unified view than could be had from the usual two- or three-day conference. This book, wh ich summarizes the morning talks by the invited speakers, is therefore of special value. The fifty-odd papers contained herein provide a remarkably complete snapshot of the field of galactic evolution as it exists in 1986. Most of the papers are excellent reviews that provide both student and professional alike with a convenient jumping-off place into the literature. Because of the wide range of topics covered, the volume mayaiso be useful as a collection of supplemental readings for graduate courses on galactic evolution. Special thanks are due to all the speakers for providing manuscripts of such uniformly high quality. Readers will note that the present volume is the first of a new series. Since the last three Santa Cruz Workshops have produced proceedings in response to public demand, it seems that this is an idea that has taken permanent root.