J/ApJ/763/15ivo://CDS.VizieR/J/ApJ/763/15doi:10.26093/cds/vizier.17630015CDSQin Y.Liang E.-W.Liang Y.-F.Yi S.-X.Lin L.Zhang B.-B.Zhang J.,Lu H.-J.Lu R.-J.Lu L.-Z.Zhang B.2018-01-05T08:57:13Z2014-10-29T07:13:04ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyThe durations (T_90_) of 315 gamma-ray bursts (GRBs) detected with Fermi/GBM (8-1000keV) up to 2011 September are calculated using the Bayesian Block method. We compare the T_90_ distributions between this sample and those derived from previous/current GRB missions. We show that the T_90_ distribution of this GRB sample is bimodal, with a statistical significance level comparable to those derived from the BeppoSAX/GRBM sample and the Swift/BAT sample, but lower than that derived from the CGRO/BATSE sample. The short-to-long GRB number ratio is also much lower than that derived from the BATSE sample, i.e., 1:6.5 versus 1:3. We measure T_90_ in several bands, i.e., 8-15, 15-25, 25-50, 50-100, 100-350, and 350-1000keV, to investigate the energy-dependence effect of the bimodal T_90_distribution. It is found that the bimodal feature is well observed in the 50-100 and 100-350keV bands, but is only marginally acceptable in the 25-50keV and 350-1000keV bands. The hypothesis of bimodality is confidently rejected in the 8-15 and 15-25keV bands. The T_90_distributions in these bands are roughly consistent with those observed by missions with similar energy bands. The parameter T_90_ as a function of energy follows {overline}{T}_90_{propto}E^-0.20+/-0.02^ for long GRBs. Considering the erratic X-ray and optical flares, the duration of a burst would be even longer for most GRBs. Our results, together with the observed extended emission of some short GRBs, indicate that the central engine activity timescale would be much longer than T_90_ for both long and short GRBs and the observed bimodal T_90_ distribution may be due to an instrumental selection effect.2013ApJ...763...15Qhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/763/15CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/20 : The Fourth BATSE Burst Revised Catalog (Paciesas+ 1999)J/ApJS/211/13 : The second Fermi/GBM GRB catalog (4yr) (von Kienlin+, 2014)J/MNRAS/431/3608 : BeppoSAX/GRBM and Fermi/GBM long GRBs (Dichiara+, 2013)J/ApJS/207/39 : IPN supplement to the Fermi GBM (Hurley+, 2013)J/ApJ/756/112 : Fermi/GBM GRB time-resolved spectral analysis (Lu+, 2012)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/ApJS/195/2 : The second Swift BAT GRB catalog (BAT2) (Sakamoto+, 2011)J/A+A/525/A53 : GBM parameters for detected FERMI bursts (Guetta+, 2011)J/ApJS/180/192 : BeppoSAX/GRBM {gamma}-ray Burst Catalog (Frontera+, 2009)http://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html : Fermi GBM bursthttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/763/15https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/763/15http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/763/15https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/763/15https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/763/15http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/763/15GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/763/15/table1 (Derived Fermi/GBM T_90_ in different energy bands)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/763/15/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/763/15/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/763/15/table1?GETtext/xml+votable180.050000true188.1054-60.27780.0055555555555555566/210 240 390 462 607 646 878 1040 1132 1161 1652 1827 2315 2503 2563 2793 2916 3038 3111 3318 3586 3598 3611 3659 3723 3806 4228 4236 4324 4450 4655 4670 5051 5139 5167 5287 5323 5625 5871 5907 5945 5991 5999 6152 6216 6261 6348 6576 6583 7164 7182 7332 7337 7364 7789 7890 7982 7987 8189 8569 8892 8966 9029 9060 9075 9215 9230 9276 9343 9431 9675 9827 10086 10400 10549 10785 10994 11220 11248 11545 11563 11904 12164 12287 12702 12826 13191 13215 13398 13559 13787 13854 13895 13938 14059 14248 14259 14555 14588 14754 14967 15201 15315 15629 16084 16137 16186 16282 16427 16430 16459 16523 16661 16692 16730 16855 16893 17170 17306 17411 17512 17530 17633 17749 17877 17938 17980 18445 18457 18777 18930 19190 19510 19544 19562 19624 19654 20077 20191 20460 20668 20820 21093 21284 21414 21490 21737 21880 21915 21998 22004 22046 22170 22181 22225 22353 22665 22838 23053 23423 23949 24113 24160 24258 24363 24378 24508 24642 24846 25174 25552 25675 25704 25708 25912 26080 26365 26632 26735 27209 27279 27289 27352 27540 27961 27962 28101 28148 28692 28729 28734 28856 28863 28930 29019 29186 29265 29449 29853 29867 30109 30237 30347 30595 30903 30982 31547 31730 31982 32153 32419 32568 32880 33061 33195 33230 33813 33922 33961 34147 34816 34917 34933 35200 35221 35336 35448 35550 35569 35633 35769 35812 35844 36444 36460 36532 36701 36851 36858 37179 37250 37281 37412 37440 37449 37510 37628 37903 37935 38362 38450 38945 38965 39076 39337 39506 39630 39829 39951 40167 40178 40272 40461 40542 40678 40778 41237 41326 41496 41936 42053 42468 42473 42545 42718 42773 42930 43045 43098 43223 43311 43385 43891 44136 44202 44277 44498 44746 44956 45088 45361 45373 45401 45464 45483 45777 45828 45868 45893 46218 46250 46594 46621 46757 46813 47031 47035 47162 47438 47770 47975 48557 48771https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/763/15?format=asciiGamma-raydefaultJ/ApJ/763/15/table1Derived Fermi/GBM T_90_ in different energy bandsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDFermi/GBM GRB identifier (YYMMDDNNN)meta.idlongGRBGRB name (YYMMDDA)meta.id;meta.maincharT8-15[0.4/262.5]? T_90_ time in 8-15keV bandstime.intervalfloatnullablee_T8-15[0.2/2.3]? Uncertainty in 8-15keVsstat.errorfloatnullableT15-25[0.3/273.2]? T_90_ time in the 15-25keV bandstime.intervalfloatnullablee_T15-25[0.1/2]? Uncertainty in 15-25keV bandsstat.errorfloatnullableT25-50[0.3/256.5]? T_90_ time in the 25-50keV bandstime.intervalfloatnullablee_T25-50[0.09/1.6]? Uncertainty in 25-50keV bandsstat.errorfloatnullableT50-100[0.2/215.5]? T_90_ time in the 50-100keV bandstime.intervalfloatnullablee_T50-100[0.1/1.6]? Uncertainty in 50-100keV bandsstat.errorfloatnullableT100-350[0.1/252.6]? T_90_ time in the 100-350keV bandstime.intervalfloatnullablee_T100-350[0.05/1.9]? Uncertainty in 100-350keV bandsstat.errorfloatnullableT350-1000[0.1/281]? T_90_ time in the 350-1000keV bandstime.intervalfloatnullablee_T350-1000[0.1/2.1]? Uncertainty in 350-1000keV bandsstat.errorfloatnullableT8-1000[0.1/261.2]? T_90_ time in the 8-1000keV bandstime.intervalfloatnullablee_T8-1000[0.05/1.6]? Uncertainty in 8-1000keV bandsstat.errorfloatnullableP12Display the GBM data from Paciesas et al. 2012, Cat. J/ApJS/199/18, if anymeta.numberintnullableV14Display the GBM data from von Kienlin et al. 2014, Cat. J/ApJS/211/13, if anymeta.numberintnullableNEDSimbad column added by the CDSmeta.ref.urlchar_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.main