Properties Of The Hard X-ray Emission From The Black Hole Candidates: Cygnus X-1 And 1E1740.7-2942

Simple item page
dc.creatorKuznetsov, S.
dc.creatorGilfanov, M.
dc.creatorChurazov, E.
dc.creatorSunyaev, R.
dc.creatorKorel, I.
dc.creatorKhavenson, N.
dc.creatorDyachkov, A.
dc.creatorNovikov, B.
dc.creatorBallet, J.
dc.creatorLaurent, P.
dc.creatorVargas, M.
dc.creatorGoldwurm, A.
dc.creatorRoques, J. P.
dc.creatorJourdain, E.
dc.creatorBouchet, L.
dc.creatorBorrel, V.
dc.date1997-04-28
dc.date.accessioned2026-07-07T02:23:17Z
dc.date.available2026-07-07T02:23:17Z
dc.descriptionThe entire dataset of the GRANAT/SIGMA observations of Cyg X-1 and 1E1740.7-2942 in 1990-1994 was analyzed in order to search for correlations between primary observational characteristics of the hard X-ray (40-200 keV) emission - hard X-ray luminosity, hardness of the spectrum (quantified in terms of the best-fit thermal bremsstrahlung temperature kT) and the RMS of short-term flux variations. Although no strict point-to-point correlations were detected certain general tendencies are evident. It was found that for Cyg X-1 the spectral hardness is in general positively correlated with relative amplitude of short-term variability. The correlation of similar kind was found for X-ray transient GRO J0422+32 (X-ray Nova Persei 1992) and recently for GX339-4. For both sources approximate correlation between kT and L_X was found. At low hard X-ray luminosity - below 10E37 erg/sec - the kT increases with increase of L_X. At higher luminosity the spectral hardness depends weaker or does not depend at all on the hard X-ray luminosity. The low luminosity end of these approximate correlations (low kT and low RMS) corresponds to extended episodes of very low hard X-ray flux occurred for both sources during SIGMA observations.
dc.description4 pages, 6 figures, uses esa_sp_latex.sty esa_sp_latex.tex, Proceedings 2nd INTEGRAL Workshop "The Transparent Universe", St. Malo, France, 16-20 September 1996. Also available at http://hea.iki.rssi.ru/~sik/PAPERS/proc96.ps.gz (gzipped PostScript)
dc.identifierhttps://arxiv.org/abs/astro-ph/9704266
dc.identifierhttp://arxiv.org/abs/astro-ph/9704266
dc.identifierESA SP-382, p. 213-216
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/11190
dc.subjectAstrophysics
dc.titleProperties Of The Hard X-ray Emission From The Black Hole Candidates: Cygnus X-1 And 1E1740.7-2942
dc.typetext

Files

Collections

arXiv