J/ApJ/787/90ivo://CDS.VizieR/J/ApJ/787/90doi:10.26093/cds/vizier.17870090CDSGolkhou V.Z.Butler N.R.2017-07-21T10:55:56Z2017-07-03T13:57:06ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyredshiftedastronomical-modelsWe develop a robust technique to determine the minimum variability timescale for gamma-ray burst (GRB) light curves, utilizing Haar wavelets. Our approach averages over the data for a given GRB, providing an aggregate measure of signal variation while also retaining sensitivity to narrow pulses within complicated time series. In contrast to previous studies using wavelets, which simply define the minimum timescale in reference to the measurement noise floor, our approach identifies the signature of temporally smooth features in the wavelet scaleogram and then additionally identifies a break in the scaleogram on longer timescales as a signature of a true, temporally unsmooth light curve feature or features. We apply our technique to the large sample of Swift GRB gamma-ray light curves and for the first time - due to the presence of a large number of GRBs with measured redshift - determine the distribution of minimum variability timescales in the source frame. We find a median minimum timescale for long-duration GRBs in the source frame of {Delta}t_min_=0.5 s, with the shortest timescale found being on the order of 10 ms. This short timescale suggests a compact central engine (3x10^3^ km). We discuss further implications for the GRB fireball model and present a tantalizing correlation between the minimum timescale and redshift, which may in part be due to cosmological time dilation.2014ApJ...787...90Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/787/90CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/711/495 : Durations of Swift/BAT GRBs (Butler+, 2010)J/ApJS/209/20 : Swift GRB catalog with X-ray data (Grupe+, 2013)J/ApJ/811/93 : Fermi/GBM GRB minimum timescales (Golkhou+, 2015)J/ApJS/224/20 : 10yr of Swift/XRT obs. of GRBs (Yi+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/787/90https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/787/90http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/787/90https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/787/90https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/787/90http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/787/90GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/787/90/table1 (GRB Minimum Timescales)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/787/90/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/787/90/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/787/90/table1?GETtext/xml+votable180.050000true291.28660.6240.0055555555555555566/186 205 207 228 236 314 338 462 500 503 646 699 866 877 918 923 1040 1102 1507 1526 1793 1882 2044 2238 2296 2315 2357 2456 2603 2793 2925 2948 2949 3038 3056 3071 3111 3267 3388 3506 3551 3586 3589 3611 3659 3675 3700 3706 3832 3894 3927 3935 3965 4296 4324 4341 4397 4449 4450 4485 4595 4829 4868 4955 5051 5080 5162 5253 5376 5525 5606 5625 5633 5726 5745 5840 5941 6004 6102 6261 6404 6445 7043 7156 7164 7182 7227 7363 7518 7532 7910 7980 8074 8182 8189 8391 8459 8569 8798 8954 9022 9069 9321 9370 9576 9714 9750 9827 9926 9989 10094 10335 10407 10447 10519 10602 10666 10680 10704 11177 11220 11248 11372 11657 11673 11713 11756 11822 11904 12134 12226 12287 12597 13312 13331 13363 13558 13694 13762 13787 13854 14020 14059 14144 14248 14259 14325 14335 14555 14754 14781 14892 14977 15246 15325 15422 15473 15513 15530 15595 15613 15683 15702 15820 15913 15915 15972 16057 16064 16072 16078 16137 16186 16232 16254 16282 16292 16375 16400 16432 16546 16661 16769 16893 16991 17279 17316 17411 17561 17721 17733 17749 17814 17914 17980 18097 18221 18445 18681 18777 18910 18930 18945 19040 19049 19164 19237 19436 19510 19544 19731 19890 20030 20191 20346 20360 20372 20393 20401 20460 20655 20668 20753 21278 21284 21360 21595 21766 21903 21915 21962 22129 22157 22422 22559 22580 22590 22619 22624 22916 23052 23138 23514 23680 23782 24041 24105 24695 25120 25131 25174 25192 25211 25312 25469 25529 25901 25946 26036 26441 26503 26910 27085 27222 27289 27302 27307 27566 27707 27810 27906 27911 27933 27962 27983 28033 28063 28202 28234 28467 28555 28692 28726 28729 28863 28867 28930 29019 29056 29179 29212 29427 29446 29456 29563 29612 29816 29867 30040 30235 30385 30461 30471 30553 30557 30595 30692 31028 31092 31185 31281 31385 31494 31547 31607 31700 31730 31847 31934 31958 31982 32058 32110 32234 32239 32467 32676 32713 32880 33004 33034 33061 33195 33265 33278 33323 33475 33482 33525 33735 33845 34147 34435 34440 34461 34465 34605 34699 34949 35045 35330 35427 35448 35525 35566 35615 35633 35702 35844 36074 36297 36374 36460 36532 36610 37007 37071 37139 37255 37324 37351 37383 37428 37459 37704 38046 38068 38301 38465 38740 38749 38926 39059 39076 39199 39224 39374 39475 39553 39630 39829 39987 40167 40249 40272 40273 40433 40482 40559 40611 40678 40778 41020 41135 41442 41555 41755 42144 42468 42473 42545 42611 42773 42840 42865 42901 42930 42952 43045 43170 43201 43280 43920 44021 44125 44160 44221 44419 44436 44493 44773 44793 44822 44857 45008 45088 45180 45205 45361 45399 45402 45468 45483 45510 45548 45729 45777 45828 45836 45938 46022 46218 46250 46510 46594 46953 47031 47117 47148 47162 47251 47459 47620 47632 47911 47991 48054 48189 48254 48319 48371 48422 48447 48458 48637 49004 49034https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/787/90?format=asciiGamma-rayOpticaldefaultJ/ApJ/787/90/table1GRB Minimum TimescalesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGRBGamma-ray burst identifier (GRB YYMMDDA in Simbad)meta.id;meta.maincharDeltmin? Minimum timescale in observer frame (1)stime.scalefloatnullablee_Deltmin? Uncertainty in Deltminsstat.errorfloatnullableDeltsnrShortest timescale with a net {sigma}_X,{Delta}t_ over Poisson level (1)stime.scale;src.netfloate_DeltsnrUncertainty in Deltsnrsstat.errorfloatT90GRB duration (2)stime.durationfloate_T90Uncertainty in T90 (2)sstat.errorfloatTR45Robust duration estimate (2)stime.durationfloate_TR45Uncertainty in TR45 (2)sstat.errorfloatsigXtmin? Fractional flux variation level ({sigma}_X,{Delta}t_) at Deltminstat.fit.paramfloatnullablesigXtsnrFractional flux variation level ({sigma}_X,{Delta}t_) at Deltsnrstat.fit.paramfloatchi2Model {chi}^2^/{nu}stat.param;meta.modelleddoubleS/NSignal-to-Noise ratio (2)stat.snrfloatz? Redshift (2)src.redshiftfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullable