Book reviews

Space Science Reviews -     

Accretion disks in stellar X-ray sources

This review presents an introduction to the theory of accretion disks. After explaining the importance of accretion disks in stellar X-ray sources, it considers observational and theoretical indications of the formation of accretion disks in close binary systems. The simple Shakura and Sunyaev model and its problems are discussed. A survey of other models that try to improve upon this model is given (in Table III), and critically discussed.     

ROSAT observations of X-ray sources in globular clusters

We review the first observations of globular clusters obtained with the X-ray telescope on board of the ROSAT satellite. In the All-Sky Survey, all known bright sources and two new transient sources were detected. In addition a super-soft source was found in NGC5272. Concerning the dim sources, the survey suggests that those outside the core of ω Cen are not related to the cluster. The survey further improved by one or two magnitudes on many upper limits previously obtained by the HEAO-1 satellite. Pointed observations have improved the positional accuracy of a number of sources, and added to the number of known dim sources. In 47 Tuc, the known central source is resolved into 4 separate sources, which we argue are all soft X-ray transients. A comparison with observations of the old open cluster M67 leads us to suggest that some of the dim sources may be conglomerates of a large number of RS Can Ven type binaries.     

Spectroscopy in Utrecht: A Brief History

In the first half of the 20th century, Leonard Ornstein turned the Physics Laboratory of Utrecht University into a center for testing the nascent quantum mechanics through accurate measurements of line intensities in flame spectra. The microphotometer of instrument builder Willem Moll was the key to this success. Marcel Minneart used this instrument to study stellar spectra at the Utrecht Astronomical Institute, and in particular for the Photometric Atlas of the Solar Spectrum. When the opportunity came in the 1960s to build instruments for research from space, it was natural that Kees de Jager opted for spectroscopy, in X-ray observations of the Sun. The expertise developed in this program allowed the Space Research Organisation of the Netherlands to be a principal player in the development of X-ray spectrographs on the Einstein, EXOSAT, Chandra and XMM-Newton satellites.     

Lee Hartmann,Accretion Processes in Star Formation

Space Science Reviews -