STScI Preprint #1267

Continuum Processes in X-Ray and -Ray Astronomy

1 Introduction
My assignment is to discuss the physics and astrophysics of continuum radiation processes in X-ray and -ray astronomy. This is an enormous subject and is central to the interpretation of observations in these wavebands. The astrophysics of X-ray and -ray sources is developing very rapidly and so I will concentrate upon basic physical processes as well as some examples of their application to current issues in X-ray and -ray astrophysics. I have no illusions about the transient nature of some of these topics, but I hope the underlying concepts and ideas may prove fruitful for understanding the literature. I should also emphasise that I am not a specialist in X-ray and -ray astronomy and so my impressions are from the outside, rather than from someone working at the coal-face every day. The topics I will cover are as follows:

• Overview of continuum processes from hot plasmas;
• Basic concepts in the radiation of charged particles;
• Bremsstrahlung;
• Synchrotron radiation;
• Inverse Compton radiation;
• Synchro-Compton radiation;
• -ray processes;
• Relativistic beaming;
• Acceleration of charged particles.

Aspects of some of these topics will be dealt with by other contributors to this volume, and you will find it illuminating to compare and contrast their treatments with mine. I make no apology for adopting a somewhat pedagogical approach to the topics listed above - my excuse is that there are numerous points where newcomers sometimes have problems and these are usually the apparently simple pieces of the story rather than the difficult bits. Finally, I make no pretense that this is a complete exposition of what you need to know. The bibliography includes texts which provide much further detail on all the above topics.

Status:

To appear in: the proceedings of the School of the European Astrophysics Doctoral Network held September 1997 in Utrecht, The Netherlands; to be published bu Springer-Verlag

(The full text can not be made available here.)

Affiliations:

¹)Space Telescope Science Institute, 3700 San Martin Drive Baltimore, 21218, MD
²)Current address: Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK