J/ApJ/933/136ivo://CDS.VizieR/J/ApJ/933/136doi:10.26093/cds/vizier.19330136CDSEspinoza-Galeas D.Corcoran M.F.Hamaguchi K.Russell C.M.P.,Gull T.R.Moffat A.F.J.Richardson N.D.Weigelt G.Hillier D.J.,Damineli A.Stevens I.R.Madura T.Gendreau K.Arzoumanian Z.,Navarete F.2025-02-24T20:13:29Z2024-11-28T12:56:07ZCDS support team

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

cds-question@unistra.frx-ray-binary-starsx-ray-sourcesWe report high-precision X-ray monitoring observations in the 0.4-10keV band of the luminous, long-period colliding wind binary Eta Carinae, up to and through its most recent X-ray minimum/periastron passage in 2020 February. Eta Carinae reached its observed maximum X-ray flux on 2020 January 7, at a flux level of 3.30x10^-10^ergs/s/cm2, followed by a rapid plunge to its observed minimum flux, 0.03x10^-10^ergs/s/cm2, near 2020 February 17. The NICER observations show an X-ray recovery from the minimum of only ~16 days, the shortest X-ray minimum observed so far. We provide new constraints for the "deep" and "shallow" minimum intervals. Variations in the characteristic X-ray temperatures of the hottest observed X-ray emission indicate that the apex of the wind-wind "bow shock" enters the companion's wind acceleration zone about 81 days before the start of the X-ray minimum. There is a steplike increase in column density just before the X-ray minimum, probably associated with the presence of dense clumps near the shock apex. During the recovery and after, the column density shows a smooth decline, which agrees with previous NH measurements made by Swift at the same orbital phase, indicating that the changes in the mass-loss rate are only a few percent over the two cycles. Finally, we use the variations in the X-ray flux of the outer ejecta seen by NICER to derive a kinetic X-ray luminosity of the ejecta of ~10^41^ergs/s near the time of the "Great Eruption."2022ApJ...933..136Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/933/136CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2014)B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)J/A+AS/133/299 : Long-term spectroscopy of eta Carinae (Damineli+ 1998)J/A+A/343/847 : Geneva Photometry of Eta Car (van Genderen+ 1999)J/A+A/419/215 : Emission lines of Sr filament near {eta} Car (Hartman+, 2004)J/AJ/129/2018 : RXTE scaled fluxes of eta Car (Corcoran+, 2005)J/ApJS/157/138 : UV spectrum of eta Car (Nielsen+, 2005)J/ApJS/163/173 : UV spectrum of eta Car in 2003.5 (Gull+, 2006)J/A+A/465/993 : Spectral atlas of massive stars around He I (Groh+, 2007)J/ApJS/168/289 : NUV spectrum of eta Car in 2003.5 (Nielsen+, 2007)J/AJ/135/1249 : The early spectra of eta Carinae (Humphreys+, 2008)J/A+A/493/1093 : BVRI light curves of {eta} Car (Fernandez-Lajus+, 2009)J/ApJS/181/473 : Analysis of the spectrum of {eta} Car (Nielsen+, 2009)J/other/NewA/15.108 : UBVRIHa of {eta} Car in 2009 (Fernandez-Lajus+ 2010)J/A+A/540/A133 : {eta} Car emission spectrum (1700-10400{AA}) (Zethson+, 2012)J/ApJ/751/73 : Equivalent widths in {eta} Cat in 1998-2012 (Mehner+, 2012)J/A+A/564/A14 : Near-infrared photometry of {eta} Carinae (Mehner+, 2014)J/A+A/578/A122 : eta Carinae's 2014.6 spectroscopic event (Mehner+, 2015)J/AJ/150/109 : Spectroscopy of {eta} Car in 2009 (Richardson+, 2015)J/ApJ/808/174 : FeII radiative transition rates (Bautista+, 2015)J/A+A/594/A106 : eta Car velocity-resolved imaging (Weigelt+, 2016)J/ApJ/838/45 : eta Car obs. around the 2014 X-ray minimum (Corcoran+, 2017)J/ApJ/914/47 : ISS/NICER X-ray observations of eta Car (Kashi+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/933/136https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/933/136http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/933/136https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/933/136https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/933/136http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/933/136GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/ApJ/933/136/table4HETG Chandra observations (0.4-10.0 keV)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsID[632/23131] Observation identifiermeta.id;obsintExptime[14703.7/102189.1] Exposure timestime;obs.exposuredoubleDateDate of observation (UT)stime.epoch;obsnullableMJD[51867.6/58875.9] Modified Julian Datedtime.epochdoublePhase[0.527/3.991] Phasetime.phasefloatJ/ApJ/933/136/table6Log of NICER observations and ratesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOBSID[1110010101/3651032801] NICER Observation identifiermeta.id;obsMJD-Start[57954/59176] Modified Julian Date at observation startdtime.start;obsdoubleMJD-End[57954/59176] Modified Julian Date at observation enddtime.end;obsdoublePhase[3.534/4.138] Phasetime.phasefloatExptime[109/9946] Exposure timestime;obs.exposurefloatCR2-10keV[0.25/32.42] Total Rate, 2.0-10.0 keVct/sarith.rate;em.X-ray.mediumfloatl_CR2-10keVNetLimit flag for CR2-10keVNetmeta.code.error;arith.rate;em.X-ray.mediumcharCR2-10keVNet[0.02/31.87] Net Rate, 2.0-10.0 keVct/sarith.rate;em.X-ray.mediumfloate_CR2-10keVNet[0.01/0.4]? Uncertainty in CR2-10keVNetct/sstat.error;arith.rate;em.X-ray.mediumfloatnullableCR2-3keV[0.05/13.07] Total Rate, 2.0-3.0 keVct/sarith.rate;em.X-ray.mediumfloatl_CR2-3keVNetLimit flag for CR2-3keVNetmeta.code.error;arith.rate;em.X-ray.mediumcharCR2-3keVNet[0.01/12.96] Net Rate, 2.0-3.0 keVct/sarith.rate;em.X-ray.mediumfloate_CR2-3keVNet[0.01/0.25]? Uncertainty in CR2-3keVNetct/sstat.error;arith.rate;em.X-ray.mediumfloatnullableCR5-7keV[0.05/4.24] Total Rate, 5.0-7.0 keVct/sarith.rate;em.X-ray.mediumfloatl_CR5-7keVNetLimit flag for CR5-7keVNetmeta.code.error;arith.rate;em.X-ray.mediumcharCR5-7keVNet[0.01/4.16] Net Rate, 5.0-7.0 keVct/sarith.rate;em.X-ray.mediumfloate_CR5-7keVNet[0.01/0.15]? Uncertainty in CR5-7keVNetct/sstat.error;arith.rate;em.X-ray.mediumfloatnullableJ/ApJ/933/136/table7NICER spectral modeling parametersNH3[3.0/5.0]? Column density, NH31e+22cm**-2phys.columnDensityfloatnullablee_NH3[0.02/5.25]? Uncertainty in NH31e+22cm**-2stat.error;phys.columnDensityfloatnullablel_kT4Limit flag for kT4meta.code.error;phys.temperature;stat.meancharkT4[1.0/2.0]? weighted average temperaturekeVphys.temperature;stat.mean;em.X-ray.mediumfloatnullablee_kT4[0.01/2.08]? Uncertainty in kT4keVstat.error;phys.temperature;stat.meanfloatnullableEM4[0.0/6.33]? Emission measure1e+58cm**-3phys.emissMeasurefloatnullablee_EM4[0.0/11.73]? Uncertainty in EM41e+58cm**-3stat.error;phys.emissMeasurefloatnullableNH5[3.0/200.0]? Column density, NH51e+22cm**-2phys.columnDensityfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOBSID[1110010101/3651032801] NICER Observation identifiermeta.id;obsPhase[3.53/4.14] Phasetime.phasefloatFlux[0.01/30.43] Flux, 10^-11^ergs/cm2/s1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_NH5[0.05/182.9]? Uncertainty in NH51e+22cm**-2stat.error;phys.columnDensityfloatnullablekT6[2.0/6.0]? weighted average temperaturekeVphys.temperature;stat.mean;em.X-ray.mediumfloatnullablee_kT6[0.1/4.02]? Uncertainty in kT6keVstat.error;phys.temperature;stat.meanfloatnullableEM6[0.04/3.88]? Emission measure1e+58cm**-3phys.emissMeasurefloatnullablee_EM6[0.02/7.42]? Uncertainty in EM61e+58cm**-3stat.error;phys.emissMeasurefloatnullableFlux-FeK[0.74/51.31]? Flux, FeK1e-05ph.cm**-2.s**-1phot.flux;em.X-ray.mediumfloatnullablee_Flux-FeK[0.6/14.8]? Uncertainty in Flux-FeK1e-05ph.cm**-2.s**-1stat.error;phot.flux;em.X-ray.mediumfloatnullablel_kT6Limit flag for kT6meta.code.error;phys.temperature;stat.meanchar