J/ApJS/268/20ivo://CDS.VizieR/J/ApJS/268/20CDSKapanadze B.Gurchumelia A.Aller M.2024-01-12T13:29:19Z2024-01-08T08:33:38ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsx-ray-sourcesvisible-astronomybroad-band-photometryultraviolet-astronomygamma-ray-astronomyThis paper presents the results of a detailed X-ray timing and spectral analysis of Mrk 501, which are based mainly on the Swift data obtained during 2021 February-2022 December. The source showed strongly enhanced X-ray activity, characterized by a long-term increase in the baseline 0.3-10keV flux level superimposed by shorter-term flares on timescales of a few weeks to about 2 months. During some time intervals, Mrk 501 was the brightest blazar in the X-ray sky and, moreover, showed an intense intraday variability, which was sometimes detected within the exposures lasting a few hundred seconds. These instances were characterized by fractional variability amplitudes of 4%-18% and were mostly observed during short-term X-ray flares. The source exhibited extreme spectral properties with dominance of the spectral curvature, frequent occurrence of hard photon indices in the 0.3-10keV and 0.3-300GeV bands, and the peak of a synchrotron spectral energy distribution in the hard X-ray range. These properties demonstrate the importance of relativistic magnetic reconnection, first-order Fermi mechanism within the magnetic field of different confinement efficiencies, stochastic acceleration, and hadronic processes. The X-ray and {gamma}-ray fluxes showed a log-normal distribution, which hints at the imprint of accretion disk instabilities on the blazar jet, as well as the possible presence of hadronic cascades and random fluctuations in the particle acceleration rate. The optical-UV and {gamma}-ray variabilities showed a weak or absent correlation with the X-ray flaring activity, which is not consistent with simple leptonic models and requires more complex particle acceleration, emission, and variability scenarios.2023ApJS..268...20Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/268/20CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/swift : Swift Master Catalog (HEASARC, 2004-)J/ApJ/663/320 : IR-through-UV extinction curve (Fitzpatrick+, 2007)J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)J/ApJS/209/14 : The Swift/BAT hard X-ray transient monitor (Krimm+, 2013)J/ApJ/831/102 : Swift and NuSTAR obs. of Mrk 421 (Kapanadze+, 2016)J/MNRAS/468/4992 : MOJAVE XIV. AGN jet shapes & angles (Pushkarev+, 2017)J/ApJS/235/39 : Jet properties of {gamma}-ray-loud 3FGL AGNs (Chen, 2018)J/ApJS/238/13 : Spectral & timing results of 1ES 1959+650 (Kapanadze+, 2018)J/ApJS/247/33 : Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)J/ApJS/247/27 : Swift obs. of Mrk 421. III. (Kapanadze+, 2020)J/A+A/668/A75 : Long-term MWL variability of 1ES 0033+595 (Kapanadze+, 2022)J/ApJS/266/37 : Time evolution of Mrk501 emission during 4yrs (Abe+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/268/20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/268/20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/268/20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/268/20https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/268/20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/268/20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayX-rayUVOpticaldefaultJ/ApJS/268/20/table2XRT observations of Mrk 501ObsIDXRT Observation identifiermeta.id;obs.param;obsintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStStart Date, YYYY-MM-DD (UTC)stime.startnullableEndStart Date, YYYY-MM-DD (UTC)stime.startnullableExpTime[240/1584] Total Exposure timestime.duration;obs.exposureintMJD[59257.5/59945.8] Modified Julian Date, observation start (JD-2400000.5)dtime.epochdoubleCR[2.5/15.6] Mean 0.3-1.0keV count ratect/sphot.count;em.X-rayfloate_CR[0.05/0.3] Error in CRct/sstat.errorfloatchi2r[0.28/37.2] Reduced {chi}^2^meta.notefloatdof[1/19] Degrees of freedom of fitstat.fit.dofintBinTime bin ("120", "60" or "Or"=Orbit)stime.intervalcharVarBrightness variability? (1)meta.codecharJ/ApJS/268/20/table3Results from the UVOT observationsJDJD start time of the observation converted from the UT start time taken in B/swiftdtime.epochcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsID[11184079/96558009] XRT Observation identifiermeta.id;obs.param;obsintFiltFilter (U, B, V, UVM2, UVW1 or UVW2)meta.id;instr.filtercharomag[13/14]? Observed magnitude in Filtmagphot.magfloatnullablee_omag[0.02/0.14]? Uncertainty in omagmagstat.error;phot.magfloatnullableFlux[2/14.4]? Observed Flux in FiltmJyphot.flux.densityfloatnullablee_Flux[0.04/0.7]? Uncertainty in FluxmJystat.error;phot.fluxfloatnullablelognuFnu[-10.52/-10.1]? Snu Flux density in Filtphot.flux.densityfloatnullablee_lognuFnu[0.007/0.06]? Uncertainty in lognuFnustat.errorfloatnullableJ/ApJS/268/20/table60.3-10keV intraday variabilities (IDVs) detected at the 99.997% and 99.5% confidence levelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSet[1/2] IDV subset (1)meta.noteintObsID2? XRT second observation ID if neededmeta.id;obsintnullableDate1Date of ObsID1time.epochnullableDate2Date of ObsID2, if neededtime.epochnullableMJD1[49576/59919] Modified Julian date, ObsID1dtime.epochintMJD2[56787/59780]? Modified Julian date, ObsID2dtime.epochintnullableExpTime[0.07/23.82] Total length of the particular observation (1)stime.expofloatchi2r[2.42/37.2] Reduced {chi}^2^meta.notefloatdof[3/25] Degrees of freedom of fitstat.fit.dofintBin[60/120]? Time binstime.intervalintnullableFvar[3.8/19.2] Fractional variability amplitude%phot.mag;arith.ratiofloate_Fvar[0.6/3] Uncertainty in fvar%stat.errorfloata1[1.6/2.2]? Logparabolic photon index, or lower limit of rangespect.indexfloatnullablee_a1[0.03/0.07]? Uncertainty in a1stat.errorfloatnullablea2[1.7/2.2]? Logparabolic photon index, upper limit of range if neededspect.indexfloatnullablee_a2[0.03/0.05]? Uncertainty in a2stat.errorfloatnullableGamma1[1.7/2.3]? 0.3-10keV photon index, or lower limit of rangespect.indexfloatnullablee_Gamma1[0.03/0.06]? Uncertainty in Gamma1stat.errorfloatnullableGamma2[1.8/2.3]? 0.3-10keV photon index, upper limit of range if neededspect.indexfloatnullablee_Gamma2[0.03/0.05]? Uncertainty in Gamma2stat.errorfloatnullableb1[0.1/2.2]? Curvature parameter, or lower limit of rangestat.fit.paramfloatnullablee_b1[0.06/0.2]? Uncertainty in b1stat.errorfloatnullableb2[0.17/0.5]? Curvature parameter, upper limit of range if neededstat.fit.paramfloatnullablee_b2[0.07/0.2]? Uncertainty in b2stat.errorfloatnullableEp1[0.26/4.3]? Synchrotron SED peak, or lower limit of rangekeVem.energyfloatnullablee_Ep1[0.08/0.4]? Uncertainty in Ep1keVstat.errorfloatnullableEp2[0.7/6]? Synchrotron SED peak, upper limit of range if neededkeVem.energyfloatnullablee_Ep2[0.09/0.6]? Uncertainty in Ep2keVstat.errorfloatnullableObsID1XRT Observation identifier, 1st observation (2)meta.id;obscharJ/ApJS/268/20/table7Results of the Swift-XRT spectral analysis with the log-parabolic modelF1[5.36/33] Unabsorbed 0.3-2keV Flux, in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.softfloate_F1[0.1/3.5] Uncertainty in F31e-14W.m**-2stat.errorfloatF2[4/27.6] Unabsorbed 2-10keV Flux, in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_F2[0.2/2] Uncertainty in F31e-14W.m**-2stat.errorfloatF3[10.7/53.3] Unabsorbed 0.3-10keV Flux, in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_F3[0.3/2] Uncertainty in F31e-14W.m**-2stat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintORSXRT Observation ID + orbit (Or#) or Segment (S#) numbermeta.id;obschara[1.62/2.19] Photon indexmeta.code;spect.indexfloate_a[0.03/0.07] Uncertainty in astat.errorfloatb[0.12/0.62] Curvature parameterstat.fit.paramfloate_b[0.06/0.17] Uncertainty in bstat.errorfloatEp[0.24/5.8] Synchrotron SED peakem.energyfloate_Ep[0.07/0.52] Uncertainty in Epstat.errorfloatK[2.11/8.94] Normalisation factor (10*K)arith.factor;phot.magfloate_K[0.06/0.26] Uncertainty in Kstat.errorfloatchi2r[0.84/1.17] Reduced {chi}^2meta.notefloatdof[52/200] Degrees of freedom of fitstat.fit.dofintJ/ApJS/268/20/table11Results of the Swift-XRT spectral analysis with a simple power-law modelrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintORSXRT Observation ID + orbit (Or#) or Segment (S#) numbermeta.id;obscharGamma[1.76/2.3] 0.3-10keV photon indexmeta.code;spect.index;em.X-ray.mediumfloate_Gamma[0.02/0.06] Uncertainty in Gammastat.errorfloatK[1.75/9.1] Normalisation factor (10*K)arith.factor;phot.magfloate_K[0.04/0.3] Uncertainty in Kstat.errorfloatchi2r[0.8/1.2] Reduced {chi}^2^meta.notefloatdof[32/165] Degrees of freedom of fitstat.fit.dofintF1[5.3/41.2] Unabsorbed 0.3-2keV Flux in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.softfloate_F1[0.16/4.1] Uncertainty in F31e-14W.m**-2stat.errorfloatF2[3.7/29.8] Unabsorbed 2-10keV Flux in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_F2[0.2/1.4] Uncertainty in F31e-14W.m**-2stat.errorfloatF3[9.89/54.7] Unabsorbed 0.3-10keV Flux in 10^-11^erg/s/cm^2^1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_F3[0.05/7] Uncertainty in F31e-14W.m**-2stat.errorfloat