J/ApJ/947/39ivo://CDS.VizieR/J/ApJ/947/39doi:10.26093/cds/vizier/ba-xk-17CDSDraghis P.A.Balakrishnan M.Miller J.M.Cackett E.Fabian A.C.,Miller-Jones J.Ng M.Raymond J.C.Reynolds M.Zoghbi A.2026-07-02T11:59:03Z2025-05-30T13:32:23ZCDS support team

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

cds-question@unistra.frblack-holesx-ray-binary-starsThe origin and distribution of stellar-mass black hole spins are a rare window into the progenitor stars and supernova events that create them. Swift J1728.9-3613 is an X-ray binary, likely associated with the supernova remnant (SNR) G351.9-0.9. An NuSTAR X-ray spectrum of this source during its 2019 outburst reveals reflection from an accretion disk extending to the innermost stable circular orbit. Modeling of the relativistic Doppler shifts and gravitational redshifts imprinted on the spectrum measures a dimensionless spin parameter of a=0.86+/-0.02 (1{sigma} confidence), a small inclination angle of the inner accretion disk {theta}<10{deg}, and a subsolar iron abundance in the disk AFe<0.84. This high spin value rules out a neutron star primary at the 5{sigma} level of confidence. If the black hole is located in a still visible SNR, it must be young. Therefore, we place a lower limit on the natal black hole spin of a>0.82, concluding that the black hole must have formed with a high spin. This demonstrates that black hole formation channels that leave an SNR, and those that do not (e.g., Cyg X-1), can both lead to high natal spin with no requirement for subsequent accretion within the binary system. Emerging disparities between the population of high-spin black holes in X-ray binaries and the low-spin black holes that merge in gravitational wave events may therefore be explained in terms of different stellar conditions prior to collapse, rather than different environmental factors after formation.2023ApJ...947...39Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/947/39CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012-)B/chandra : The Chandra Archive Log (CXC, 1999-2014)J/MNRAS/426/1701 : High-frequency QPO in black hole binaries (Belloni+, 2012)J/ApJ/800/17 : Mass-transfer sequences in 16 Galactic LMXBs (Fragos+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/947/39https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/947/39http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/947/39https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/947/39https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/947/39http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/947/39GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/ApJ/947/39/fig2Light curve of the NuSTAR observationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/308] Sequential bin numberem.binintTime[0/55500] Timestime.epochfloatCR[2.7/7] Count rate (panel 1 in Figure 2) (1)ct/sphot.count;em.X-raydoublee_CR[0.3/2.3] Uncertainty in CRct/sstat.error;phot.count;em.X-raydoubleRatio1[4.2/6] 3-7keV to 7-10keV ratio (panel 2 in Figure 2)phot.count;arith.ratio;em.X-ray.mediumdoublee_Ratio1[0.1/1.1] Uncertainty in Ratio1stat.error;phot.count;arith.ratiodoubleRatio2[7.4/13.1] 3-7keV to 10-20keV ratio (panel 3 in Figure 2)phot.count;arith.ratio;em.X-raydoublee_Ratio2[0.3/2.3] Uncertainty in Ratio2stat.error;phot.count;arith.ratiodoubleRatio3[34.2/88.5] 3-7keV to 20-79keV ratio (panel 4 in Figure 2)phot.count;arith.ratio;em.X-ray.mediumdoublee_Ratio3[2.7/61.2] Uncertainty in Ratio3stat.error;phot.count;arith.ratiodoubleRatio4[6.9/19.1] 7-10keV to 20-79keV ratio (panel 5 in Figure 2)phot.count;arith.ratio;em.X-ray.mediumdoublee_Ratio4[0.6/15.1] Uncertainty in Ratio4stat.error;phot.count;arith.ratiodoubleJ/ApJ/947/39/fig3Unfolded and modeled spectrum of Swift J1728.9-3613e_ResArelx[1]? Uncertainty in ResArelxstat.error;stat.fit.residualfloatnullableEnergy3Bx[3/78] Residuals to FPMB spectrum for constant*TBabs*(diskbb+relxill) model, EnergykeVphys.energy;em.X-raydoublee_Energy3Bx[0.07/8] Uncertainty in Energy3BxkeVstat.error;phys.energy;em.X-raydoubleResBrelx[-2.5/3.6] Residuals to FPMB spectrum for constant*TBabs*(diskbb+relxill) model, {sigma} (Panel c in Figure 3)stat.fit.residualdoublee_ResBrelx[1] Uncertainty in panel2Bystat.error;stat.fit.residualfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/127] Sequential bin numberem.binintEnergy[3/73]? FPMA spectrum, EnergykeVphys.energy;em.X-raydoublenullablee_Energy[0.07/7]? Uncertainty in EnergykeVstat.error;phys.energy;em.X-raydoublenullableFluxA[0.4/5.2]? FPMA spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoublenullablee_FluxA[0.01/0.04]? Uncertainty in FluxAkeV**2stat.error;phot.flux;em.X-raydoublenullableFluxATot[0.4/5.2]? Total model, FPMA spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoublenullableFluxAdisk[9.2e-19/3.8]? Diskbb model component, FPMA spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoublenullableFluxArelx[0.4/1.5]? Relxill model component, FPMA spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoublenullableFluxB[0.58/5.3] FPMB spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoublee_FluxB[0.01/0.2] Uncertainty in FluxBkeV**2stat.error;phot.flux;em.X-raydoubleFluxBTot[0.4/5.3] Solid line, Total model, FPMB spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoubleFluxBdisk[2.5e-21/4] Diskbb model component, FPMB spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoubleFluxBrelx[0.4/1.6] Relxill model component, FPMB spectrum, Flux (Panel a in Figure 3) (1)keV**2phot.flux;em.X-raydoubleEnergy2Ax[3/73]? Residuals to FPMA spectrum for constant*TBabs*(diskbb+powerlaw) model, EnergykeVphys.energy;em.X-raydoublenullablee_Energy2Ax[0.07/7]? Uncertainty in Energy2AxkeVstat.error;phys.energy;em.X-raydoublenullableResA[-5.7/5]? Residuals to FPMA spectrum for constant*TBabs*(diskbb+powerlaw) model, {sigma} (Panel b in Figure 3)stat.fit.residualdoublenullablee_ResA[1]? Uncertainty in ResAstat.error;stat.fit.residualfloatnullableEnergy2Bx[3/78] Residuals to FPMB spectrum for constant*TBabs*(diskbb+powerlaw) model, EnergykeVphys.energy;em.X-raydoublee_Energy2Bx[0.07/8] Uncertainty in Energy2BxkeVstat.error;phys.energy;em.X-raydoubleResB[-4.6/4.5] Residuals to FPMB spectrum for constant*TBabs*(diskbb+powerlaw) model, {sigma} (Panel b in Figure 3)stat.fit.residualdoublee_ResB[1] Uncertainty in ResBstat.error;stat.fit.residualfloatEnergy3Ax[3/73]? Residuals to FPMA spectrum for constant*TBabs*(diskbb+relxill) model, EnergykeVphys.energy;em.X-raydoublenullablee_Energy3Ax[0.07/8]? Uncertainty in Energy3AxkeVstat.error;phys.energy;em.X-raydoublenullableResArelx[-3.6/2.5]? Residuals to FPMA spectrum for constant*TBabs*(diskbb+relxill) model, {sigma} (Panel c in Figure 3)stat.fit.residualdoublenullable