Search Publications
The COS-B X-ray observations of X-ray binaries.
van der Klis, M.
The observational information on X-ray binaries that was collected with the 80 sq cm auxiliary X-ray detector onboard the COS-B gamma-ray satellite is reviewed. The results illustrate that in the study of X-ray binaries observations of long duration are extremely effective, even when using a small instrument.
The COS-B X-ray observations of X-ray binaries
van der Klis, M.
The observational information on X-ray binaries that was collected with the 80 cm2 auxiliary X-ray detector onboard the COS-B gamma-ray satellite is reviewed. The results illustrate that in the study of X-ray binaries observations of long duration are extremely effective, even when using a small instrument.
COS-B views on the diffuse galactic gamma-ray emission and some point sources
Hermsen, W.
The correlation between diffuse galactic gamma rays and gas tracers is studied using the final COS-B database and H i and CO surveys covering the entire galactic plane. A good quantitative fit to the gamma rays is obtained, with a small galacto-centric gradient in the gamma-ray emissivity per hydrogen atom. The average ratio of H2 colum…
Cygnus X-3 not Seen at High-Energy Gamma-Rays
Hermsen, W.
The ESA satellite COS-B viewed the Cyg-X region 7 times between November 1975 and March 1982. A search for periodic gamma-ray emission (E > 70 MeV) from Cyg X-3 at the characteristic ∼4.8 h period did not reveal the source. Combining all observations, the 2σ upperlimit (E > 70 MeV) on the flux for the phase interval in which X-ray emission h…
Gamma-Ray Sources Observed by Cos-B
Hermsen, W.
The nature of the fine-scale structure in the gamma-ray distribution is not yet disclosed. Considerable debate is going on whether these structures which appear point-like in the data, are mainly diffuse in nature or are genuinely compact objects. Most of the uncertainty is due to the experimental limitations. A status report is presented on the e…
The Use of Gamma-Rays to Trace the Local Interstellar Hydrogen
Strong, A. W.
COS-B data in the latitude range 11° <¦b¦ < 19° show the gamma-ray intensity to be closely correlated with the total line-of-sight absorption derived from galaxy counts. It is found that to a good approximation the gamma-ray intensity is proportional to the total gas column density, and on this basis a map of the angular distribution of loca…
Cos-B X-Ray Observations of CYGNUS-X-3 - an Indications for Apsidal Motion
van der Klis, M.; Bonnet-Bidaud, J. M.
Results are presented of three ∼40 d COS-B X-ray observations of Cyg X-3. The shape of the 4.8 h light curve showed variations on all observational time scales. An ∼20 d periodicity was found in the arrival time of the minimum of the light curve, interpreted as apsidal motion of an orbit with an eccentricity of ∼0.03.