%0 Journal Article %@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S} %@nexthigherunit 8JMKD3MGPCW/3ETR8EH %3 1-s2.0-S0273117701004367-main.pdf %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. %N 2-3 %T HEXTE studies of SCO X-1 spectra: detections of hard X-ray tails beyond 200 Kev %K ASTROFÍSICA, espectro raio X, estrela de neutron, binarias raio X, buracos negros, X ray spectra, neutron stars, X ray binaries, black holes. %@secondarytype PRE PI %@archivingpolicy denypublisher denyfinaldraft24 %@usergroup administrator %@usergroup jefferson %@group DAS-INPE-MCT-BR %@secondarykey INPE-8644-PRE/4378 %F 9618 %@issn 0273-1177 %2 sid.inpe.br/iris@1905/2005/08.02.21.48.47 %B Advances in Space Research %@versiontype publisher %P 389-394 %4 sid.inpe.br/iris@1905/2005/08.02.21.48.44 %@documentstage not transferred %D 2001 %V 28 %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., %@dissemination WEBSCI; PORTALCAPES; MGA; COMPENDEX. %@area CEA