J/ApJ/862/155ivo://CDS.VizieR/J/ApJ/862/155doi:10.26093/cds/vizier.18620155CDSLan L.Lu H.-J.Zhong S.-Q.Zhang H.-M.Rice J.Cheng J.-G.Du S.-S.,Li L.Lin J.Lu R.-J.Liang E.-W.2025-05-22T20:11:28Z2023-10-05T12:30:20ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomygamma-ray-burstsTwo-episode emission components separated by quiescent gaps in the prompt emission of gamma-ray bursts (GRBs) have been observed in the Swift era, but there is a lack of spectral information due to the narrow energy band of the Swift/Burst Alert Telescope. In this paper, a systematic analysis of the spectral and temporal properties of the prompt emission of 101 Fermi/Gamma-ray Burst Monitor detected long GRBs show the existence of two-episode emission components in the light curves, with quiescent times of up to hundreds of seconds. We focus on investigating the differences of those two emission episodes. We find that the light curves of the two emission components exhibit different behavior, e.g., a soft emission component that either precedes or follows the main prompt emission or that the intensity of the two emission episodes are comparable with each other. No statistically significant correlation in the duration of the two emission episodes can be claimed. We define a new parameter {epsilon} as the ratio of the peak flux of the first and second emission episodes and find that a higher {epsilon} corresponds to a larger fluence. The preferred spectral model in our analysis is a cutoff power-law model for most GRBs. The distribution of E_p_ for episodes I and II range from tens of keV to 1000 keV with a lognormal fit and there are no significant differences between them. Moreover, we do not find significant relationships between {epsilon} and E_p_ for the two emission episodes. Those results suggest that these two-episode emission components likely share the same physical origin.2018ApJ...862..155Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/862/155CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/720/1146 : Spectral analysis of GRBs (Lu+, 2010)J/ApJ/754/121 : GRBs from Fermi/GBM and LAT (The Fermi Team, 2012)J/ApJS/199/18 : The Fermi GBM catalog (Paciesas+, 2012)J/ApJ/756/112 : Fermi/GBM GRB time-resolved spectral analysis (Lu+, 2012)J/ApJ/763/15 : Fermi GRB analysis. III. T_90_ distributions (Qin+, 2013)J/ApJ/787/66 : Burst duration measurements for a GRB sample (Zhang+, 2014)J/ApJ/865/153 : Analysis of Fermi GRB data. IV. Spectral lags (Lu+, 2018)J/ApJ/886/20 : Bayesian time-resolved spectra of Fermi GBM pulses (Yu+, 2019)J/ApJ/893/46 : The 4th Fermi-GBM GRB catalog: 10 years (von Kienlin+, 2020)J/ApJ/913/60 : GRB energetics from Fermi-GBM 10years (Poolakkil+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/862/155https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/862/155http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/862/155https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/862/155https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/862/155http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/862/155GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/862/155/table1 (Results of the temporal and spectral analysis of 101 GRBs in our sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/862/155/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/862/155/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/862/155/table1?GETtext/xml+votable180.050000true358.332.90.0055555555555555566/137 240 607 646 2507 2942 3637 3684 3881 4347 4449 4487 5098 5148 5153 5530 6047 6214 8023 8320 8333 8932 9524 9817 11220 12438 12826 14065 14448 14516 14655 15340 15485 15588 15940 16572 17140 17464 17646 18538 18697 18731 18783 18897 18901 19500 19588 19694 20077 20414 20426 20453 20668 20736 21100 21756 22299 23406 25174 25916 26415 26910 27249 27964 29449 29731 30066 30310 32419 33240 33306 34461 34831 35738 35764 37505 38282 38319 38615 38944 39023 39304 39594 40044 40484 40957 41522 42710 43278 44228 44277 45137 45464 45483 46000 47201 47975 48171 48387 48934 48953https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/862/155?format=asciiGamma-raydefaultJ/ApJ/862/155/table1Results of the temporal and spectral analysis of 101 GRBs in our samplee_EpII[2/440] EpII uncertaintykeVstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFermiTrigger ID (bnYYMMDDddd)meta.id;meta.maincharTEI[0.4/80.3] Duration of the first emission episode, T_E,I_stime.durationfloatFpI[0.17/123] Flux of the first emission episode in 10^-7^erg/cm^2^/s, F_p,I_1e-10W.m**-2phot.flux.density;em.gamma.hardfloate_FpI[0.05/21] FpI uncertainty1e-10W.m**-2stat.errorfloatEpI[34/947] Peak energy of CPL model fits of the first emission episode, E_p,I_keVem.energyfloate_EpI[1/235] EpI uncertaintykeVstat.errorfloatalpI[0.05/1.94] The low energy photon index of CPL model fits for the first emission episode, {alpha}_I_meta.codefloate_alpI[0.01/0.3] alpI uncertaintystat.errorfloatChi2I[193/326] Fit {chi}^2^ for the first emission episodestat.fit.param;meta.modelledintdofI[232/241] Dof for the first emission episodestat.fit.dofintTq[5.4/223.4] The quiescent times that are calculated from the end of the first episode to the beginning of the second episodestime.epochfloatTEII[1.6/137] Duration of the second emission episode, T_E,II_stime.intervalfloatFpII[0.98/167] Flux of the second emission episode in 10^-7^erg/cm^2^/s, F_p,II_1e-10W.m**-2phot.flux.density;em.gamma.hardfloate_FpII[0.09/21] FpII uncertainty1e-10W.m**-2stat.errorfloatEpII[18/1362] Peak energy of CPL model fits of the second emission episode, E_p,II_keVem.energyfloatalpII[0.13/2.2] The low energy photon index of CPL model fits for the second emission episode, {alpha}_II_meta.codefloate_alpII[0.01/0.4] alpII uncertaintystat.errorfloatChi2II[177/316] Fit {chi}^2^ for the second emission episodestat.fit.param;meta.modelledintdofII[235/241] Dof for the second emission episodestat.fit.dofint_RAPositions from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD (declination part)degpos.eq.dec;meta.main