J/ApJ/772/73ivo://CDS.VizieR/J/ApJ/772/73doi:10.26093/cds/vizier.17720073CDSKopac D.Kobayashi S.Gomboc A.Japelj J.Mundell C.G.Guidorzi C.,Melandri A.Bersier D.Cano Z.Smith R.J.Steele I.A.Virgili F.J.2017-06-22T14:29:05Z2015-03-06T06:37:38ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyvisible-astronomysloan-photometryredshiftedWe present a multi-wavelength analysis of Swift gamma-ray burst GRB 090727, for which optical emission was detected during the prompt {gamma}-ray emission by the 2m autonomous robotic Liverpool Telescope and subsequently monitored for a further two days with the Liverpool and Faulkes Telescopes. Within the context of the standard fireball model, we rule out a reverse shock origin for the early-time optical emission in GRB 090727 and instead conclude that the early-time optical flash likely corresponds to emission from an internal dissipation process. Putting GRB 090727 into a broader observational and theoretical context, we build a sample of 36 {gamma}-ray bursts (GRBs) with contemporaneous early-time optical and {gamma}-ray detections. From these GRBs, we extract a sub-sample of 18 GRBs, which show optical peaks during prompt {gamma}-ray emission, and perform detailed temporal and spectral analysis in {gamma}-ray, X-ray, and optical bands. We find that in most cases early-time optical emission shows sharp and steep behavior, and notice a rich diversity of spectral properties. Using a simple internal shock dissipation model, we show that the emission during prompt GRB phase can occur at very different frequencies via synchrotron radiation. Based on the results obtained from observations and simulation, we conclude that the standard external shock interpretation for early-time optical emission is disfavored in most cases due to sharp peaks ({Delta}t/t<1) and steep rise/decay indices, and that internal dissipation can explain the properties of GRBs with optical peaks during {gamma}-ray emission.2013ApJ...772...73Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/772/73CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/20 : The Fourth BATSE Burst Revised Catalog (Paciesas+ 1999)J/A+A/557/A12 : Optical light curves of {gamma}-ray bursts (Zaninoni+, 2013)J/ApJS/209/20 : Swift GRB catalog with X-ray data (Grupe+, 2013)J/MNRAS/428/729 : GRB Swift X-ray light curves analysis (Margutti+, 2013)J/MNRAS/421/2692 : Optical/NIR observations of GRB 080310 (Littlejohns+, 2012)J/MNRAS/421/1874 : GRB 100901A and GRB 100906A light curves (Gorbovskoy+, 2012)J/ApJ/746/170 : Follow-up resources for high-redshift GRBs (Morgan+, 2012)J/A+A/530/A21 : Spectral properties of 438 GRBs (Nava+, 2011)J/ApJS/195/2 : The second Swift BAT GRB catalog (BAT2) (Sakamoto+, 2011)J/AJ/141/36 : GRB 080607 multi-band light curves (Perley+, 2011)J/ApJ/743/154 : Multi-band phot. of GRB 110205A + 110213A (Cucchiara+, 2011)J/ApJ/720/1513 : The afterglows of Swift-era GRBs. I. (Kann+, 2010)J/ApJ/711/495 : Durations of Swift/BAT GRBs (Butler+, 2010)J/ApJ/702/489 : ROTSE observations of GRB afterglows (Rykoff+, 2009)J/ApJ/701/824 : Afterglows of short and long-duration GRBs (Nysewander+, 2009)J/ApJ/691/723 : BVIJHKs observations of GRB 080319B (Bloom+, 2009)J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)J/ApJS/180/192 : BeppoSAX/GRBM {gamma}-ray Burst Catalog (Frontera+, 2009)J/PAZh/35/10 : Gamma-ray bursts with known redshifts (Badjin+, 2009)J/ApJ/672/449 : GRB 061126 light curves (Perley+, 2008)J/A+A/473/347 : BeppoSAX complete catalogue of GRBs (Vetere+, 2007)J/A+A/455/813 : BeppoSAX catalog of GRB X-ray afterglows (De Pasquale+, 2006)J/A+A/427/87 : List of GRBs (Gorosabel+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/772/73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/772/73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/772/73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/772/73https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/772/73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/772/73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/772/73/table5 (*General properties of GRBs in the master sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/772/73/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/772/73/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/772/73/table5?GETtext/xml+votable180.050000true231.377544.7666670.0055555555555555566/500 699 2044 3059 3586 5726 5840 7532 9910 10519 11657 13312 13924 15348 15613 16078 18777 18978 19164 19731 20030 23138 25946 27933 30557 31281 31385 31494 33735 38926 39076 40433 44021 45777 47162 48458https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/772/73?format=asciiGamma-rayOpticaldefaultJ/ApJ/772/73/table5*General properties of GRBs in the master samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGRBGRB namemeta.id;meta.maincharprimaryn_GRB[abcl] Individual notes (1)meta.notecharT90[15/600] Burst duration with 5-95% of fluence (2)sphot.fluencefloatr_T90Flag on T90 (2)meta.ref;pos.framecharz[0.3/6.3]? Redshiftsrc.redshiftfloatnullablef_z[*] *: not a spectroscopic redshiftmeta.codecharE[0.02/28]? Isotropic {gamma}-ray energy release (E^{gamma}^_iso_) in 10^53^erg1e+46Jphys.energyfloatnullableLCLight Curve morphology (3)meta.codecharr_LC? Optical Light Curve morphology reference (see refs.dat file)meta.ref;pos.frameintnullableT8Included in the sub-sample? (Yes ot No)meta.codecharNgSimbad column added by the CDSmeta.numberintnullableRefReference for z and E (see refs.dat file)meta.ref;pos.framecharNotesNotes in the corresponding Appendix number; also given the optical emission referencesmeta.notecharSimbadSimbad column added by the CDSmeta.ref.urlcharNEDSimbad 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.mainJ/ApJ/772/73/table8Early time optical and {gamma}-ray flux densities and spectral indices for 18 GRBs in the sub-sampleGRBGRB name (1)meta.id;meta.maincharf_GRB[*] Flag on GRB (2)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTmidTime of mid-exposure since GRB trigger timestime.epochfloatExpExposure timestime.duration;obs.exposurefloatnuOpt[4.8/8.6] Optical frequency {nu}_opt_1e+14Hzem.freqfloatFOptOptical flux density (3)mJyphot.flux.densitydoublee_FOptUncertainty in FOptmJystat.errorfloatnuGR[4.6/27] {gamma}-ray frequency1e+18Hzem.freqfloatFGR{gamma}-ray flux densityuJyphot.flux.densityfloate_FGRUncertainty in FGRuJystat.errorfloatbetaGPower-law slope {beta}_{gamma}_ of {gamma}-ray spectrum ({beta}_{gamma}_={Gamma}-1)spect.indexfloate_betaGThe 90% confidence interval in betaGstat.errorfloatbetaG-OPower-law slope of optical-to-{gamma} indexspect.indexfloate_betaG-OThe 90% confidence interval in betaG-Ostat.errorfloatJ/ApJ/772/73/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.notecharBibCodeBibcodemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharCommComment (catalog's reference in VizieR)meta.ref;pos.frame;meta.tablecharJ/ApJ/772/73/table2GRB 090727 optical photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTmidTime of mid-exposure since GRB trigger timestime.epochdoubleExp[10/1800] Exposure timestime.duration;obs.exposureintTelTelescope: FTN=Faulkes Telescope North, or LT=2-m Liverpool Telescopeinstr.telcharFiltFilter (r',i', z' or R)src.redshift;instr.filtercharl_magLimit flag on magmeta.code.errorcharmag[18.3/23.4] Magnitude in Filt; corrected for the Galactic extinctionmagphot.magfloate_mag[0.1/0.5]? mag uncertaintymagstat.error;phot.magfloatnullablel_FOptLimit flag on FOptmeta.code.errorcharFOpt[0.001/0.2] Optical flux density (1)mJyphot.flux.densityfloate_FOpt[0.0007/0.02]? FOpt uncertaintymJystat.errorfloatnullable