J/A+A/447/245ivo://CDS.VizieR/J/A+A/447/245doi:10.26093/cds/vizier.34470245CDSWilms J.Nowak M.A.Pottschmidt K.Pooley G.G.Fritz S.2006-04-08T23:31:00Z2006-04-08T23:28:24ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frx-ray-binary-starsvariable-starsContinuing the observational campaign initiated by our group, we present the long term spectral evolution of the Galactic black hole candidate Cygnus X-1 in the X-rays and at 15GHz. We present about 200 pointed observations taken between early 1999 and late 2004 with the Rossi X-ray Timing Explorer and the Ryle radio telescope. The X-ray spectra are remarkably well described by a simple broken power law spectrum with an exponential cutoff. Physically motivated Comptonization models, e.g., by Titarchuk (1994ApJ...434..570T, compTT) and by Coppi (1999, eqpair), can reproduce this simplicity; however, the success of the phenomenological broken power law models cautions against ``over-parameterizing'' the more physical models. Broken power law models reveal a significant linear correlation between the photon index of the lower energy power law and the hardening of the power law at about 10keV. This phenomenological soft/hard power law correlation is partly attributable to correlations of broad band continuum components, rather than being dominated by the weak hardness/reflection fraction correlation present in the Comptonization model. Specifically, the Comptonization models show that the bolometric flux of a soft excess (e.g., disk component) is strongly correlated with the compactness ratio of the Comptonizing medium, with L_disk{propto}(l_h_/l_s_)^-0.19^. Over the course of our campaign, Cyg X-1 transited several times into the soft state, and exhibited a large number of ``failed state transitions''. The fraction of the time spent in such low radio emission/soft X-ray spectral states has increased from about 10% in 1996-2000 to about 34% since early 2000. We find that radio flares typically occur during state transitions and failed state transitions (at l_h_/l_s_~3), and that there is a strong correlation between the 10-50keV X-ray flux and the radio luminosity of the source. We demonstrate that rather than there being distinctly separated states, in contrast to the timing properties the spectrum of Cyg X-1 shows variations between extremes of properties, with clear cut examples of spectra at every intermediate point in the observed spectral correlations.2006A&A...447..245Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/447/245CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AZh/78/408 : Variability of Cyg X-1 in 1994-1998 (Karitskaya+, 2001)J/PAZh/26/27 : Variability of Cyg X-1 (V1357) in 1995-1996 (Karitskaya+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/447/245https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/447/245http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/447/245https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/447/245https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/447/245http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/447/245GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/447/245/table1Best-fit results for the broken power-law modelrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsStartDate of the start of the observation, YYYY-MM-DDThh:mm:ssstime.start;obsnullableObsEndDate of the end of the observation, YYYY-MM-DDThh:mm:ssstime.epochnullableMJDStartMJD of the start of observationdtime.epochdoubleMJDStopMJD of the end of observationdtime.epochdoubleExpTimeExposure timestime.duration;obs.exposureintCRCount ratect/sphot.count;em.X-rayfloate_CRrms uncertainty on CRct/sstat.errordoubleFph(2-5)2-5keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(2-5)2-5keV band energy fluxmW.m**-2phot.flux;em.X-ray.mediumdoubleFph(5-10)5-10keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(5-10)5-10keV energy fluxmW.m**-2phot.flux;em.X-raydoubleFph(10-50)10-50keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(10-50)10-50keV band energy fluxmW.m**-2phot.flux;em.X-ray.harddoubleFph(50-100)50-100keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(50-100)50-100keV band energy fluxmW.m**-2phot.flux;em.X-ray.harddoubleFph(2-100)2-100keV band photon flux (G1)cm**-2.s**-1phot.flux.density;em.gamma.hardfloatFene(2-100)2-100keV band energy fluxmW.m**-2phot.flux;em.X-ray.harddoublechi2chi2 valuestat.fit.chi2floatDOFDegree of freedomstat.fit.dofintchi2redReduced chi2 valuestat.fit.chi2doublenHHydrogen column density1e+22cm**-2phys.columnDensitydoublee_nH90% uncertainty range on nH1e+22cm**-2stat.errordoublecutoffECutoff energykeVem.energydoublee_cutoffE90% uncertainty range on cutoffEkeVstat.errordoubleFoldEFolding energykeVem.energyfloate_FoldE90% uncertainty range on FoldEkeVstat.errorfloatlineEFe Kalpha line energykeVspect.line.intensityfloate_lineE90% uncertainty range on LineEkeVstat.errorfloatlineEsigmaFe Kalpha width (sigma)keVspect.line.widthdoublee_lineEsigma90% uncertainty range on lineEsigmakeVstat.errordoublelineENFe Kalpha norm (total photons in line)spect.line.intensitydoublee_lineEN90% uncertainty range on lineENstat.errordoublePI1Photon index below break energymeta.codefloate_PI190% uncertainty range on PI1stat.errorfloatBreakEBreak energykeVem.energyfloate_BreakE90% uncertainty range on BreakEkeVstat.errorfloatPI2Photon index above break energymeta.codefloate_PI290% uncertainty range on PI2stat.errorfloatbknpowerNPhoton flux of bkn powerlaw at 1keVstat.fit.paramfloate_bknpowerN90% uncertainty range on bknpoweNstat.errordoubleFactorFlux normalization factorstat.fit.paramdoublee_Factor90% uncertainty range on Factorstat.errordoubleJ/A+A/447/245/table2Best-fit results for the compTT modelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsStartDate of the start of the observation, YYYY-MM-DDThh:mm:ssstime.epochnullableObsEndDate of the end of the observation, YYYY-MM-DDThh:mm:ssstime.epochnullableMJDStartMJD of the start of observationdtime.epochdoubleMJDStopMJD of end of observationdtime.epochdoubleExpTimeExposure timestime.duration;obs.exposureintCRCount ratect/sphot.count;em.X-rayfloate_CRrms uncertainty on CRct/sstat.errordoubleFphDiskAccretion disk unabsorbed photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFeneDiskAccretion disk unabsorbed energy fluxmW.m**-2phot.flux;em.X-raydoubleFphTotalBolometric unabsorbed photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFeneTotalBolometric unabsorbed energy fluxmW.m**-2phot.flux;em.X-raydoubleFph(2-5)2-5keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(2-5)2-5keV band energy fluxmW.m**-2phot.flux;em.X-ray.mediumdoubleFph(5-10)5-10keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(5-10)5-10keV energy fluxmW.m**-2phot.flux;em.X-raydoubleFph(10-50)10-50keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(10-50)10-50keV band energy fluxmW.m**-2phot.flux;em.X-ray.harddoubleFph(50-100)50-100keV band photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(50-100)50-100keV band energy fluxmW.m**-2phot.flux;em.X-ray.harddoublechi2chi2 value of the best fitstat.fit.chi2floatDOFDegree of freedomstat.fit.dofintchi2redReduced chi2 valuestat.fit.chi2doublenHHydrogen column density1e+22cm**-2phys.columnDensitydoublee_nH90% uncertainty range on nH1e+22cm**-2stat.errordoubleTinInner disk temperaturekeVphys.temperaturedoublee_Tin90% uncertainty range on TinkeVstat.errordoublediskbbNNorm of disk (see XSPEC manual)meta.notefloate_diskbbN90% uncertainty range on diskbbNstat.errordoublekTTemperature of Comptonizing plasmakeVphys.temperaturefloate_kT90% uncertainty range on kTkeVstat.error;phys.energydoubletaupOptical depth of Comptonizing plasmaphys.absorption.opticalDepthdoublee_taup90% uncertainty range on taupstat.errordoublecompTTNNorm of compTT modelstat.paramdoublee_compTTN90% uncertainty range on compTTNstat.errordoubleReflomega/2pi for the reflecting mediumstat.paramdoublee_Refl90% uncertainty range on Reflstat.errordoubleReflsigmaomega/2pi for the reflecting medium (sigma)keVstat.paramdoublee_Reflsigma90% uncertainty range on ReflsigmakeVstat.errordoubleReflNomega/2pi for the reflecting medium normstat.paramdoublee_ReflN90% uncertainty range on ReflNstat.errordoubleFactorFlux normalization factorstat.fit.paramdoublee_Factor90% uncertainty range on Factorstat.errordoubleJ/A+A/447/245/table3Best-fit results for the eqpair modelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsStartEarliest time entering observation, YYYY-MM-SSThh:mm:ssstime.epochnullableObsEndLatest time entering observation, YYYY-MM-SSThh:mm:ssstime.epochnullableMJDStartMJD of the start of observationstime.epochdoubleMJDStopMJD of the end of observationstime.epochdoubleTimeExpExposure time of each filestime.epoch;meta.fileintCRCount rate of each filect/sphot.count;em.X-rayfloate_CRrms uncertainty of each count ratect/sstat.errordoubleFphDiskAccretion disk unabsorbed photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFeneDiskAccretion disk unabsorbed energy fluxmW.m**-2phot.flux;em.X-raydoubleFphTotalBolometric unabsorbed photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFeneTotalBolometric unabsorbed energy fluxmW.m**-2phot.flux;em.X-raydoubleFph(2-5)2-5keV band Photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(2-5)2-5keV band Energy fluxmW.m**-2phot.flux;em.X-ray.mediumdoubleFph(5-10)5-10keV band Photon flux (G1)cm**-2.s**-1phot.flux;em.X-rayfloatFene(5-10)5-10keV band Energy fluxmW.m**-2phot.flux;em.X-ray.mediumdoubleFph(10-50)10-50keV band Photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(10-50)10-50keV band Energy fluxmW.m**-2phot.flux;em.X-ray.harddoubleFph(50-100)50-100keV Photon flux (G1)cm**-2.s**-1phot.flux;em.X-raydoubleFene(50-100)50-100keV band Energy fluxmW.m**-2phot.flux;em.X-ray.harddoublechi2Chi-squared value of the best fitstat.fit.chi2floatDOFDegrees of freedomstat.fit.dofintchi2redReduced Chi-squaredstat.fit.chi2doublenHHydrogen column density1e+22cm**-2phys.columnDensitydoublee_nH90% uncertainty range of nH parameter1e+22cm**-2stat.errordoubleTinInnner disk temperaturekeVphys.temperaturedoublee_Tin90% uncertainty range of Tin parameterkeVstat.errordoubleDiskbbNnorm of the diskmeta.notedoublee_DiskbbN90% uncertainty range of DiskbbNstat.errordoubleLineEFe Kalpha line energykeVspect.line.intensityfloate_LineE90% uncertainty range of LineEkeVstat.errorfloatLineEsigmaFe Kalpha line widthkeVspect.line.widthdoublee_LineEsigma90% uncertainty range of LineEsigmakeVstat.errordoubleLineENFe Kalpha norm (total photons in line)phot.count;em.X-raydoublee_LineEN90% uncertainty range of LineENstat.errordoublelhlsRatio of hard to soft compactnessmeta.code;phys.sizedoublee_lhls90% uncertainty range of lhlsstat.errordoubletaupoptical depth of Comptonizing plasmaphys.absorption.opticalDepthdoublee_taup90% uncertainty range of taupstat.errordoubleReflOmega/2pi for reflecting mediumstat.paramdoublee_Refl90% uncertainty range of Reflstat.errordoublexiIonization parameter of reflectorphys.ionizParamdoublee_xi90% uncertainty range of xistat.errordoubleeqpairNNorm of eqpair modelstat.paramdoublee_eqpairN90% uncertainty range of eqpairNstat.errordoubleFactorFlux normalization factorstat.fit.paramdoublee_Factor90% uncertainty range of Factorstat.errordouble