Ray Astronomy

Advances in X-ray astronomy have led to good spectra of energetic objects like supernova remnants (see Fig. 3.30) and the hot gas in clusters of galaxies (see Fig. 3.31), from which some deductions about abundances can be made subject to realistic modelling, which is not always straightforward. The SNR shown in... 

They have been thrust to the forefront of cosmology, a boon for nuclear astrophysics The satellite INTEGRAL, dedicated to nuclear gamma-ray astronomy and on the point of spreading its wings, carries all the hopes and aspirations of the scientific community to which 1 belong. 

The launch of the American satellite Uhuru brought about a revolution in X-ray astronomy. The discovery of double X-ray sources, neutron stars, and black holes (the three candidates at present) fully confirmed the correctness of the accretion course chosen long before by Ya.B. [24 ], and made him a leading theoretical authority in international X-ray astronomy. 

The 16th Solvay Conference in Physics, held in September 1973, was entitled Astrophysics and Gravitation. 110 The progress undergone in many fundamental chapters of astrophysics with respect to the previous conference, held in 1964, was really striking. In particular, X-ray astronomy had won a status comparable with other conventional branches of astronomy. 

See Jim Lochner, NASA, X-ray Astronomy Supernovae and their remnants, http //imagine.gsfc.nasa.gov/docs/science/know ll/supernovae.html)... 

Moulton, Forest Ray. Astronomy. The Macmillan Company, New York. 1931. 

Keywords Imaging Air Cherenkov Telescopes, Gamma Ray Astronomy... 

The excess significance is 5.1 standard deviations (a), in accordance with the Li and Ma theory [9], which is usually applied within the gamma ray astronomy field. The initial significance was 5.6 a, it has been reduced in order to account for the position indetermination of the source. 

Rotation Modulation Collimators (RMC s) were originally introduced in X-ray astronomy to provide accurate source localizations over extended fields. This role has since been taken over by the grazing incidence telescope systems. The potential of the RMC s as wide field monitors have recently been demonstrated by the WATCH instruments on GRAN AT and EURECA. It now appears likely, that for use on large, 3-axis stabilized spacecraft, a pinhole camera system may provide better sensitivity than an RMC-system of corresponding physical dimensions. But due to its simplicity, low data rate, and ability to work on spin stabilized (micro)satellites, the RMC wide field monitor may still have a role to play in the X-ray astronomy of the future. 

The Rotation Modulation Collimator was originally conceived by Mertz [9] as a technique to encode an image formed in the focal plane of an optical Schmidt-telescope to allow electronic read-out by a photomultiplier. The technique was soon adapted to image forming in X-ray astronomy by Schnopper et al. [11], and was successfully used in a number of rocket flights to localize X-ray sources with good precision [12,14]. In 1974 the UK ARIEL-V and in 1975 the NASA SAS-3 satellite was launched both equipped with RMC systems. The source localizations provided by ARIEL-V and SAS-3 led to the discovery of many new X-ray sources and the identification of the optical counterparts of several sources [13,15,16]. 

Key words Mosaic crystals - X-Ray imaging - Concentrators - X-ray Astronomy... 

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