J/ApJ/902/146ivo://CDS.VizieR/J/ApJ/902/146doi:10.26093/cds/vizier.19020146CDSLeahy D.Wang Y.2022-09-05T14:22:28Z2022-05-12T15:00:12ZCDS support team

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

cds-question@unistra.frx-ray-binary-starsx-ray-sourcesSwift/BAT and RXTE/ASM observations have monitored the X-ray binary system Her X-1 for approximately 14.5yr each, and both were monitoring Her X-1 for a period of ~5.5yr. Here we study the 35d cycle using these observations. Using a cross-correlation method we find the times of peaks of the 35 day cycles for ~150 cycles observed by Swift/BAT and ~150 cycles observed by RXTE/ASM. These cycles include ~60 observed with both instruments. The noise level of the RXTE/ASM measurements is larger than that of Swift/BAT, resulting in larger uncertainty in peak times. The distribution of 35d cycle lengths can be fit with a Gaussian with mean 34.79d and {sigma} of 1.1d. The distribution of orbital phases of 35 day cycle peaks is well fit by a uniform distribution, with 76% of the cycles, plus a Gaussian distribution peaked at orbital phase ~0.5, with 24% of the cycles. We construct the long-term average 35 day lightcurve in the 15-50keV band from Swift/BAT, and in the 2-12keV band from RXTE/ASM. The high-energy band shows more variability in the short high state and the low-energy band shows more variability in the main high state. This is consistent with a precessing accretion disk model as the cause of the 35d cycle.2020ApJ...902..146Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/902/146CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2014)B/swift : Swift Master Catalog (HEASARC, 2004-)B/xmm : XMM-Newton Observation Log (XMM-Newton Science Operation Center, 2012)B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)V/106 : Catalogue of X-ray binaries (Liu+ 2001)J/AZh/79/1087 : UBV photometry of X-ray binary HZ Her (Sheffer+, 2002)J/A+A/467/785 : SuperWASP/ROSAT periodic variable stars (Norton+, 2007)J/A+A/522/A68 : Variable sources detected by INTEGRAL (Telezhinsky+, 2010)J/ApJS/187/149 : StarCAT: STIS UV echelle spectra of stars (Ayres, 2010)J/AJ/141/129 : Chandra Transmission Grating Data Cat. (Huenemoerder+, 2011)J/A+A/548/A79 : INTEGRAL-OMC optically var. sources (Alfonso-Garzon+, 2012)J/ApJS/209/14 : The Swift/BAT hard X-ray transient monitor (Krimm+, 2013)J/A+A/550/A110 : Her X-1 pulse profiles (Staubert+, 2013)J/BaltA/24/395 : X-ray and radio sources in binaries (Malkov+, 2015)J/other/NewA/47.81 : Distances of X-ray binaries (Islam+, 2016)J/ApJS/223/15 : 8yr INTEGRAL/IBIS soft gamma-ray source obs. (Bird+, 2016)J/A+A/625/A122 : CIELO-RGS, soft X-ray ionized emission lines cat. (Mao+, 2019)J/A+A/645/A18 : SVOM-ECLAIRs known X-ray sources catalogue (Dagoneau+, 2021)http://xte.mit.edu/asmlc/ASM.html : RXTE ASM Light Curves home pagehttp://swift.gsfc.nasa.gov/results/transients/ : Swift/BAT Hard X-ray Transienthttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/902/146https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/902/146http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/902/146https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/902/146https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/902/146http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/902/146GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/ApJ/902/146/table1Swift/BAT cyclesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNumB[0/151] Cycle numbermeta.numberintMJD[53437.82/58692] Modified Julian Date of the main high state (MH) peak time (G1)dtime.epochdoubleLength[31.2/39.5] Cycle length (G1)dtime.intervalfloatPhase[-1/0.998] MH peak orbital phase (G1)(G2)time.phasedoubleLabel[0/2]? Label of cycle (G3)meta.codeintnullableJ/ApJ/902/146/table2RXTE/ASM cyclesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNumA[2/162] Cycle number (1)meta.numberintMJD[50146.5/55705.5] Modified Julian Date of the main high state (MH) peak time (G1)dtime.epochdoubleLength[-1/38.7] Cycle length (G1)dtime.intervalfloatPhase[-1/0.99] MH peak orbital phase (G2)time.phasedoubleLabel[0/1]? Label of cycle (G3)meta.codeintnullableJ/ApJ/902/146/table4ASM & BAT comparison for overlap periodrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNumA[97/162] Cycle number for ASMmeta.numberintNumB[0/65] Cycle number for BATmeta.numberintdt[-1.27/1.6] MH peak time difference; ASM-BATdtime.epoch;arith.diff;stat.maxdoubledphi[-1.11/1.92] MH peak orbital phase difference; ASM-BATtime.phase;arith.diffdouble