These contributions by recognized authorities originate from a Royal Society discussion meeting held to review the most recent results obtained from the current generation of X-ray telescope research. The launch of Chandra and XMM-Newton has revolutionized research in X-ray astronomy over the past few years, and high quality X-ray observations now being made have had a major impact on topics ranging from protostars to cosmology. This book is a valuable reference for research astronomers and graduate students.