%0 Journal Article
%4 sid.inpe.br/iris@1905/2005/08.02.21.48.44
%2 sid.inpe.br/iris@1905/2005/08.02.21.48.47
%@issn 0273-1177
%F 9618
%T HEXTE studies of SCO X-1 spectra: detections of hard X-ray tails beyond 200 Kev
%D 2001
%A D'Amico, Flávio,
%A Heindl, W. A.,
%A Rothschild, R. E.,
%A Peterson, L. E.,
%A Gruber, D. E.,
%A Pelling, M.,
%A Tomsick, J. A.,
%B Advances in Space Research
%V 28
%N 2-3
%P 389-394
%K ASTROFÍSICA, espectro raio X, estrela de neutron, binarias raio X, buracos negros, X ray spectra, neutron stars, X ray binaries, black holes.
%X Using the HEXTE experiment on-board the RXTE satellite, we performed a search for hard X-ray tails in Sco X-1 spectra. We found strong evidence for the presence of such a non-thermal component on several occasions. Using the PCAIRXTE we were able to track the position of the source along the Z diagram, and we observed that the presence of the hard X-ray tail is not confined to a particular region. However, we found a correlation between the power law index of the non-thermal component and the position of the source in the Z diagram, suggesting that the hard X-ray spectrum (i.e., E > 50 keV)becomes flatter as the mass accretion rate increases. We were also able to study the temporal variation of the appearance/absence of the hard X-ray component. With our derived luminosities, we were also able to test the idea that X-ray luminosities can be used to distinguish between X-ray binary systems containing neutron stars and black holes.
%@language en
%3 1-s2.0-S0273117701004367-main.pdf