J/ApJ/904/L21ivo://CDS.VizieR/J/ApJ/904/L21doi:10.26093/cds/vizier.19049021CDSYounes G.Guver T.Kouveliotou C.Baring M.G.Hu C.-P.Wadiasingh Z.,Begicarslan B.Enoto T.Gogus E.Lin L.Harding A.K.,van der Horst A.J.Majid W.A.Guillot S.Malacaria C.2022-06-13T12:54:07Z2022-04-11T06:58:15ZCDS support team

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

cds-question@unistra.frneutron-starsx-ray-sourcesgamma-ray-astronomygamma-ray-burstsWe report on NICER observations of the magnetar SGR1935+2154, covering its 2020 burst storm and long-term persistent emission evolution up to ~90days postoutburst. During the first 1120s taken on April 28 00:40:58 UTC, we detect over 217 bursts, corresponding to a burst rate of >0.2bursts/s. Three hours later, the rate was 0.008bursts/s, remaining at a comparatively low level thereafter. The T90 burst duration distribution peaks at 840ms; the distribution of waiting times to the next burst is fit with a lognormal with an average of 2.1s. The 1-10keV burst spectra are well fit by a blackbody, with an average temperature and area of kT=1.7keV and R2=53km^2^. The differential burst fluence distribution over ~3 orders of magnitude is well modeled with a power-law form dN/dF {prop}F-1.5{+/-}0.1. The source persistent emission pulse profile is double-peaked hours after the burst storm. We find that the burst peak arrival times follow a uniform distribution in pulse phase, though the fast radio burst associated with the source aligns in phase with the brighter peak. We measure the source spin-down from heavy-cadence observations covering days 21-39 postoutburst, {nu}=-3.72(3)x10^-12^Hz/s, a factor of 2.7 larger than the value measured after the 2014 outburst. Finally, the persistent emission flux and blackbody temperature decrease rapidly in the early stages of the outburst, reaching quiescence 40days later, while the size of the emitting area remains unchanged.2020ApJ...904L..21Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/904/L21CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/527/A139 : X-ray bursting neutron star atmos. models (Suleimanov+, 2011)J/A+A/545/A120 : X-ray burst neutron star atmos. models II (Suleimanov+, 2012)J/ApJS/218/11 : The 5 year Fermi/GBM magnetar burst catalog (Collazzi+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/904/L21https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/904/L21http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/904/L21https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/904/L21https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/904/L21http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/904/L21GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayX-raydefaultJ/ApJ/904/L21/table1Spectral properties of the persistent emissionRad[1.5/4] Radiuskmphys.size.radiusfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsIDNICER observation identifiermeta.id;obs.param;obsMJD[58967/59057] Modified Julian Date, exposure midpoint, MJD-2400000.5dtime.epochdoubleTexp[222/5177] Exposurestime.duration;obs.exposurefloatCR[0.12/2.74] Count rates**-1phot.count;em.X-rayfloate_CR[0.01/0.2] Uncertainty in CRs**-1stat.errorfloatkT[0.34/0.79] Average temperaturekeVphys.temperaturefloate_kT[0.01/0.1] Lower uncertainty on kTkeVstat.error;phys.energyfloatE_kT[0.01/0.1] Upper uncertainty on kTkeVstat.error;stat.maxfloatFlux[0.14/2.2] 0.3-10keV flux, unabsorbed1e-14W.m**-2phot.flux;em.X-ray.mediumfloate_Flux[0.01/0.1] Lower uncertainty on F1e-14W.m**-2stat.error;phot.fluxfloatE_Flux[0.01/0.1] Upper uncertainty on F1e-14W.m**-2stat.error;stat.maxfloate_Rad[0.1/2] Lower uncertainty on Radkmstat.errorfloatE_Rad[0.1/3] Upper uncertainty on Radkmstat.error;stat.maxfloatJ/ApJ/904/L21/table2*Burst propertiesBurst[1/223] Burst numbermeta.idintTpeak[0/7] Burst Peak time, hour UTCtime.epochrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGTI[1/4] uninterrupted good time intervaltime.intervalintTst[0/7] Burst Start time, hour UTCtime.epochTet[0/7] Burst End time, hour UTCtime.epochT90[0.06/30.9] burst durationstime.durationfloatR2[2/970]? emission areakm**2phys.areafloatnullablekT[0.5/3.9]? average temperaturekeVphys.temperaturefloatnullablee_kT[0.02/1]? Lower uncertainty on kTkeVstat.error;phys.energyfloatnullableE_kT[0.02/5]? Upper uncertainty on kTkeVstat.error;stat.maxfloatnullablee_R2[1/560]? Lower uncertainty on R2km**2stat.errorintnullableE_R2[3/1300]? Upper uncertainty on R2km**2stat.error;stat.maxintnullablelogF[-9.6/-6.26]? log10, 0.5-10 keV Flux, erg/s/cm2log(0.001W.m**-2)phot.flux;em.X-rayfloatnullablee_logF[0.01/0.2]? Lower uncertainty on logFlog(0.001W.m**-2)stat.errorfloatnullableE_logF[0.01/0.2]? Upper uncertainty on logFlog(0.001W.m**-2)stat.error;stat.maxfloatnullable