There is little to add to the remarks which I made in the preface to Volume 1 of High energy astrophysics. The process of revising and updating the first edition has resulted in a very major expansion in the length of the text, so that it could not be contained within a single volume. I had hoped to complete the work in two volumes, but, as the work progressed, it became apparent that the second volume would have become unwieldy, and so this book is Volume 2 of what will be a three-volume work. In this volume, I concentrate upon the high energy astrophysics of our own Galaxy, and Volume 3 will be devoted to extragalactic high energy astrophysics.

It is worthwhile explaining the point of view which I have adopted in introducing the various topics contained in Volumes 2 and 3. As in the first edition, my aim has been to produce self-contained texts which include most of the essential astronomy and astrophysics needed to understand the context as well as the content of high energy astrophysics. For this reason, the present volume begins with descriptions of the current picture of the large-scale distribution of matter and radiation in the Universe, as well as a broad survey of relevant astrophysics, before getting down to studying the high energy astrophysics in detail. In my view, it is no longer possible, if it ever was, to consider the high energy processes independently of the astrophysical environments within which they take place.