Gamma astronomy

A new era of European supremacy will open up in the domain of nuclear gamma astronomy, for no large-scale project has been proposed across the Atlantic to take up where the CGRO observatory left off. Let us hope that European science will make the most of this boon. ... 

The best illustration of radioactive astronomy is titanium-44. We shall take it as the archetype of a good radioactive isotope. It is relatively abundant and has a reasonable lifetime of around 100 years, neither too long, nor too short. Only aluminium-26 can rival it in this respect and nuclear gamma astronomy has already reaped some of the rewards (see Fig. 4.4). 

The revelatory power of the new astronomy, especially astronomy associated with the extreme forms of radiation, resides in its capacity to expose previously unknown processes to reason and understanding gamma astronomy, the most violent phenomena in the Universe, such as the rupture and destruction of stars, and infrared astronomy, the gentle events, such as the birth of stars. Optical astronomy fills the relatively calm gap between stellar birth and death, whilst millimetre radioastronomy opens our minds to the formation of molecular structure in great clouds of cold gases and opaque dusts, far from any devastating light. 

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. 

Astronomy s new eyes carry code names like HST (Hubble Space Telescope), XMM (X-ray Multi-Mirror) and GRO (Gamma-Ray Observatory). Each wavelength region has its own squadron, extended by future spacecraft that take us ever further towards sensitivity and detailed analysis of images and spectra. 

As gamma rays pay no heed to lenses and mirrors, INTEGRAL is a rather special telescope, resembhng rather a nuclear physics installation than an astronomical instrument. As a result, its resolving power will be much lower than that of an optical, UV or X-ray telescope. The identification of gamma sources will thus require support from more conventional forms of astronomy. INTEGRAL is an ESA project. 

UV, X-ray and gamma-ray observatories are all space-borne because these wavelengths are blocked by the Earth s atmosphere. And what could be more natural than to place eyes in orbits But who sent them up there and why Astrophysicists are no longer naive when it comes to the relationship between the tools of military surveillance and those of astronomy. And this is not a recent invention. Galileo himself offered his refracting telescope to the delighted dignitaries of the Venetian senate in order to draw attention to its military potential. His salary was immediately doubled and he was appointed professor at the University of Padua ... 

These gamma-ray detections of5 Co and 57Co in supernova 1987A are among the most important observations in the history of astronomy. This gave birth to a... 

D.Yu. Tsvetkov, S.I. Blinnikov, N.N. Pavlyuk (2001). Gamma-ray Bursts, Type Ib/c Su-pemovae and Star-forming Sites in Host Galaxies , Astronomy Letters, v.27, issue 7, pp.411-415. 

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

Aharonian, F. A., Akhperjanian, A.-G., Aye, K., et al. (2004c). Very high energy gamma rays from the direction of Sagittarius A. Astronomy and Astrophysics, 425 L13. 

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. 

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