J/ApJ/800/16ivo://CDS.VizieR/J/ApJ/800/16doi:10.26093/cds/vizier.18000016CDSBoer M.Gendre B.Stratta G.2017-10-03T05:13:08Z2015-07-28T07:53:54ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyThe discovery of a number of gamma-ray bursts (GRBs) with duration exceeding 1000s has opened the debate on whether these bursts form a new class of sources, the so-called ultra-long GRBs, or if they are rather the tail of the distribution of the standard long GRB duration. Using the long GRB sample detected by Swift, we investigate the statistical properties of long GRBs and compare them with the ultra-long burst properties. We compute the burst duration of long GRBs using the start epoch of the so-called "steep decay" phase detected with Swift/XRT. We discuss also the differences observed in their spectral properties. We find that ultra-long GRBs are statistically different from the standard long GRBs with typical burst duration less than 100-500s, for which a Wolf-Rayet star progenitor is usually invoked. Together with the presence of a thermal emission component we interpret this result as indication that the usual long GRB progenitor scenario cannot explain the extreme duration of ultra-long GRBs, their energetics, as well as the mass reservoir and size that can feed the central engine for such a long time.2015ApJ...800...16Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/800/16CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/711/495 : Durations of Swift/BAT GRBs (Butler+, 2010)J/ApJ/701/824 : Afterglows of short & long-duration GRBs (Nysewander+, 2009)J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)J/AJ/133/1027 : Positions for 179 Swift X-ray afterglows (Butler+, 2007)J/A+A/448/L9 : Position catalogue of Swift XRT afterglows (Moretti+, 2006)http://www.swift.ac.uk/xrt_live_cat : The Swift-XRT GRB online cataloguehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/800/16https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/800/16http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/800/16https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/800/16https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/800/16http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/800/16GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/800/16/table1 (Our long GRB sample and the associated duration of the burst event in X-rays until the steep decay, taken from the XRT GRB catalog best fit parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/800/16/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/800/16/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/800/16/table1?GETtext/xml+votable180.050000true184.089291720.20902780.0055555555555555566/186 207 314 393 462 500 503 866 877 923 1882 2238 2258 2296 2315 2456 2473 2735 2949 3111 3388 3586 3935 4312 4449 4788 5525 5606 5625 5745 5791 5941 6404 7084 7156 7300 7518 7532 8182 8669 8761 8798 8932 8954 9321 9330 9395 9714 9989 10135 10407 10602 10723 10852 10912 11307 11372 11649 11673 12020 12134 12155 12226 13558 13694 13889 13898 13924 14248 14846 14852 14892 14977 15530 15915 15972 15995 16064 16072 16078 16186 16292 16375 16400 16546 17316 17411 17561 17733 18097 18221 18258 18494 18728 18930 19168 19331 19544 19731 20372 20655 20668 20753 20883 21284 21595 21766 21915 21962 22157 22559 22590 24041 25174 25394 25529 25946 26036 26076 26831 26910 27962 28071 28496 28555 28630 28930 29446 30235 30385 30461 30692 30785 31028 31092 31143 31281 31521 31583 31607 31847 32058 32110 32234 32467 32713 33146 33265 33278 33482 33617 34147 34461 34590 35045 35330 35393 35566 35569 35844 36292 36374 37324 37383 38068 38465 38504 39076 39224 39374 39912 40272 40273 40389 40559 40611 42901 42952 43045 43201 44419 44436 44822 45008 45399 45483 45725 45729 45777 45938 46022 46218 46395 46510 46953 47162 47436 47911 47945 48054 48189 48319 48422 49004 49034https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/800/16?format=asciiGamma-raydefaultJ/ApJ/800/16/table1Our long GRB sample and the associated duration of the burst event in X-rays until the steep decay, taken from the XRT GRB catalog best fit parametersSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGRBGamma Ray Burst identifier (YYMMDDA)meta.id;meta.maincharTX[48/25400] Duration (T_X_)stime.durationdoubleE09Sources within 10" from Evans+, 2009, J/MNRAS/397/1177meta.ref.urlintnullableNEDSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main