J/ApJ/951/94ivo://CDS.VizieR/J/ApJ/951/94doi:10.26093/cds/vizier/ba-xq-2yCDSWani K.Gaur H.Patil M.K.2026-07-02T12:00:00Z2025-09-24T09:29:02ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsx-ray-sourcesHigh synchrotron energy peaked blazar 1ES 1959+650 was studied with the Swift and XMM-Newton satellites in a total of 127 observations during the period 2018 June-2020 December. We extensively studied its flux and spectral variability on intraday and long-term timescales. Discrete correlation function analysis between soft and hard X-ray bands indicates soft as well as hard lags. The results were used to constrain the magnetic field of the emitting region, which was found to be 0.64+/-0.05G. On long-term timescales, the distribution of fluxes shows lognormal behavior, which could be attributed to the minijets-in-a-jet model or might be due to the propagation of relativistic shocks down the jet. The spectral energy distribution around the synchrotron peak is well described by the log-parabola model. Spectral parameters like the peak energy Ep, curvature {beta}, and peak luminosity Lp were derived from spectral analysis. Their correlations were studied to constrain the acceleration processes of the emitting particles. Ep shows strong correlation with Lp during the high state of the source, which indicates spectral changes might be caused by the variations of the average electron energy. Low values of the curvature parameter {beta} and a weak correlation between Ep and {beta} indicate the coexistence of stochastic/statistical acceleration of electrons in the emitting region. Implications of other results are also discussed.2023ApJ...951...94Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/951/94CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/swift : Swift Master Catalog (HEASARC, 2004-)B/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012-)J/ApJS/97/1 : HST Quasar Absorption Line Key Project. X. (Lockman+ 1995)J/ApJ/617/262 : X-ray sources in NGC 1600 (Sivakoff+, 2004)J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)J/MNRAS/421/1861 : OJ287 polarization and VLBI jet direction (Valtonen+, 2012)J/ApJ/848/103 : ~1.5yr Swift observations of Mrk 421 (Kapanadze+, 2017)J/ApJS/238/13 : Spectral & timing results of 1ES 1959+650 (Kapanadze+, 2018)J/ApJS/247/27 : Swift obs. of Mrk 421. III. ~3yr obs. (Kapanadze+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/951/94https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/951/94http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/951/94https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/951/94https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/951/94http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/951/94GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/ApJ/951/94/obsObservation log of XMM-Newton and Swift-XRT data for blazar 1ES 1959+650 (Table 1), best spectral fit parameters for the Power Law and Log Parabolic Model (Table 2) and results of Chi2 test for hardness ratio analysis (Table 4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTelSatellite ("Swift-XRT" or "XMM-Newton")meta.id;instr.telcharobsIDObservation identifiermeta.id;obsOrbitOrbit numbermeta.id;meta.maincharObs[2018/2020] Observation year'Y:M:D'time.epochExpTime[114.5/42140] Exposure timestime.duration;obs.exposuredoubleFvar