Prof. Immo Appenzeller is the emeritus director of the Heidelberg Observatory (Landessternwarte Heidelberg). From 1994 - 1997 he served as General Secretary of the International Astronomical Union. He was PI or CO of various large national and international instrumentation and research projects. His current main research topics are very distant (young) galaxies, active galaxies and QSOs, massive luminous stars, cosmic X-ray sources, astronomical instrumentation.
From the reviews: “This ambitious book aims to summarize our view of high-redshift galaxies and their contents. … He describes how to find high-redshift objects, how to characterize them, how to deal with selection effects, and so on. … Appenzeller has done a fine job in summarizing the study of high-redshift galaxies and this will act as an excellent introduction to the subject for students and researchers.” (Paul O’Brien, The Observatory, Vol. 130 (1214), February, 2010)