Extragalactic Astronomy and Cosmology

Abstract

Amazing times! I finished the manuscript for the first edition of this book just 8 years ago—but the necessity of a new edition was urgently felt. In these years we have witnessed an enormous development in the field of extragalactic astronomy and cosmology. On the instrument side, the final servicing mission to the Hubble Space Telescope brought two new very powerful instruments to this unique observatory, the Herschel and Planck satellites were launched and conducted their very successful missions, the South Pole Telescope and the Atacama Cosmology Telescope started operation, ALMA was inaugurated and began observations, and new powerful high-resolution instruments were installed on 10-m class telescopes. Scientifically, the redshift frontier has been extended, with candidate galaxies at redshifts of ten or higher and stellar explosions seen at redshifts beyond eight, a much improved understanding of the high-redshift galaxy population has been obtained, as a consequence of which also the origin of the cosmic infrared background is now understood, and greatly improved multi-wavelength surveys carried out with the most powerful telescopes, together with new simulation techniques, have provided us with a much better understanding of the evolution of the galaxy population. The Pierre Auger observatory has shed much light on the origin of the most energetic cosmic rays, and the advances of atmospheric Cherenkov telescopes have identified dozens of active galaxies emitting at energies of teraelectron Volts. Several blind surveys have detected galaxy clusters by their Sunyaev–Zeldovich effect, providing a new and powerful route for cluster cosmology. WMAP has finished its 9 years of surveying the microwave sky, and confirmed two of the predictions of inflation—the spatial flatness of our Universe and the finite tilt of the initial power spectrum. The first cosmological results from Planck were stunning, including an all-sky map of the gravitational potential which is responsible for lensing the cosmic microwave background. The use of baryonic acoustic oscillations as a standard rod to measure the geometry of our Universe has by now been firmly established. Two Nobel prizes in physics, given to cosmologists in 2006 and 2011 for studies of the cosmic microwave background and for the discovery of the accelerated expansion of the Universe using Type Ia supernovae, highlight the impact of this science in the broader physics context. In this second edition, I have tried to account for these new developments, by updating and (in some cases, substantially) expanding many sections. New material has been added, including a separate chapter on galaxy evolution, as well as sections on the standard model of elementary particles andWIMPs as dark matter candidates, properties of high-redshift galaxies and the galaxy population in clusters, and several other topics. Following the suggestion of several reviewers of the first edition, problems (and solutions) have been added to most chapters. However, I have tried to preserve the style and level of the original book, aiming at a text which combines the physical exploration of cosmic objects with the fascination of astronomical and cosmological research.