Search Publications
Large-scale distribution of galactic gamma radiation observed by COS-B
Caraveo, P. A.; Bignami, G. F.; Hermsen, W. +13 more
A complete survey of the Galaxy in high-energy gamma rays was performed aboard the ESA satellite COS-B. Gamma-ray maps were derived for energy ranges between 70 MeV and 5 GeV from 1975-1979, and are presented as both contour maps and as longitude and latitude profiles for three energy intervals. The spectral ratio is derived in the form of a color…
COS-B gamma-ray measurements, cosmic rays and the local interstellar medium
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +7 more
A study of the relation between galaxy counts and gamma rays measured by the COS-B satellite clearly shows that there exists a bidimensional correlation between these quantities. Though the 21 cm measurements are more accurate than galaxy counts they show a weaker correlation with gamma rays. A significant fraction of the local gas in molecular fo…
The local interstellar medium as traced by gamma rays
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +8 more
Gamma-ray flux measurements (70-5000 MeV) made with the COS-B satellite have been used to study the distribution of total gas column density in the latitude range from 11 deg to 19 deg. A close correlation with the distribution found from galaxy counts exists. The dominant structure is associated with Gould's Belt, but several other major features…
On the spin down episodes of Vel X-1.
Molteni, D.; Robba, N. R.; Rapisarda, M. +1 more
The ESA COS-B satellite observed the X-ray source Vela X-1 in July/August 1976 and in October/November 1979 in the energy range 2-12 keV. Different pulse periods, 282.819 and 282.782 s, were determined for the two observations respectively. These values confirm the presence of spin up and spin down processes in this source.
The X-ray flux variations of CYG X-2.
van der Klis, M.; Bonnet-Bidaud, J. M.
Results of a 47 d observation of Cygnus X-2 by the COS-B X-ray experiment are presented. The observed variability of the X-ray intensity is investigated for the presence of modulation at either the 9.843 d optical period or the 11.23 d X-ray period claimed for this source. Upper limits are given to pulse amplitudes for periods between 1 d and 200 …
Discrete sources of cosmic gamma rays
Wolfendale, A. W.; Li, T. P.
The possibility is considered that some unidentified gamma-ray sources are in fact not discrete sources but rather 'apparent sources' caused by cosmic-ray irradiation of the clumpy interstellar medium. It is shown that six of nine unidentified gamma-ray sources in the 2CG catalog can be explained in terms of the mechanism considered and that the s…