Active galactic nuclei (AGN) are among the most interesting astrophysical objects in the Universe. IAU Symposium 304, dedicated to marking the centenary of B. E. Markarian's birth, addresses the most important questions in this area: understanding the possible evolutionary and/or physical connections between the different classes of AGN; the relation of AGN to their host galaxies; and understanding the true fraction of heavily obscured AGN in order to determine the true AGN luminosity function and its variation with redshift. This volume's topics include: historical spectral and colorimetric surveys, multiwavelength AGN surveys, AGN statistics, unification and other models of AGN, AGN feedback in galaxies and clusters, their host galaxies and environments, binary AGN and merging supermassive black holes, AGN variability, and future large projects. This fresh summary of AGN surveys is especially useful for researchers engaged in this exciting field and helping them plan for future surveys and observations.

A lavish coffee-table book featuring spectacular images from the Chandra X-Ray Observatory, the most powerful X-Ray telescope ever built Take a journey through the cosmos with Light from the Void, a stunning collection of photographs from the Chandra X-Ray Observatory's two decades of operation. The book showcases rarely-seen celestial phenomena such as black holes, planetary nebulae, galaxy clusters, gravitational waves, stellar birth and death, and more. Accompanying these images of incredible natural phenomena are captions explaining how they occur. The images start close to home and move outward: beginning with images of the Chandra launch, then moving into the solar system, through the nearby universe, and finally to the most distant galaxies Chandra has observed, the book brings readers on a far-out visual voyage.

Blazars (also known as BL Lac objects), first discovered in 1978, are unusually energetic objects in the extragalactic universe. About 200 are known or suspected. They are radio sources with highly variable optical and radio emission, as well as high polarisation, and their optical spectra normally have no distinguishable features. It is generally accepted that they belong to that class of galaxies with active galactic nuclei, which are presumed to be driven by infall of matter to a supermassive black hole. In this book researchers give a complete summary of the observations of blazars and the theoretical interpretation. A comprehensive listing of confirmed and candidate objects is included. Mechanisms in which the variability can arise from shocks and relativistic jets are discussed. There are at least four different answers given to the question: what is a blazar? This book is a complete overview of the violent activity observed in these extreme active galactic nuclei.

The book collects 29 papers which have been particularly influential in the development of accretion theory. As an introductory paper a recent review on the subject is reported. An extensive list of references closes the volume.

Knowing the distance of an astrophysical object is key to understanding its formation and evolution. Without an accurate distance, we do not know how bright it is, how large it is, or even when it existed. This volume highlights the tremendous amount of recent and continuing research into a myriad of exciting and promising aspects of accurately pinning down the cosmic distance scale, where possible focused on space-based contributions. These papers go one step further, putting the many recent results and new developments into the broader context of the physics driving cosmic distance determination. Thus, the volume will benefit researchers spanning a wide range of expertise, including theorists, observers, and modelers working on a large variety of spatial scales. Originally published in Space Science Reviews in the Topical Collection "Astronomical Distance Determination in the Space Age"