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Gamma-Ray Bursts Detected by INTEGRALS.Foley,L.Hanlon,S.McBreen,S.McGlynn,B.McBreenSchool of PhysicsUniversity College DublinIBIS maskJEM-X masksIBIS detectorJEM-X detectorsSPIOptical MonitorINTEGRAL InstrumentsSPI SPectrometer on INTEGRALCoded MaskGermaniumDetector Array 19 Ge detector array energy range of 15 keV to 8 MeV high energy resolution 2 keV at 1 MeV fully coded field of view16 corner to corner limited imaging capabilityIBIS Imager on Board the INTEGRAL SatelliteCodedMask ISGRIPICsIT Full imaging capability-FWHM 12 Fully coded field of view 9 x 9 ISGRI energy range20 keV 1 MeV 128 x 128 CdTe pixels Moderate energy resolution PICsIT energy range 200 keV 10 MeV 64 x 64 CsI pixelsIBAS Integral Burst Alert Systemibas.mi.iasfr.it Automatic system for the rapid distribution of GRBcoordinates INTEGRALs 72-hour highly eccentric orbit allows foralmost continuous data transmission to ground Ground-based IBAS localisations based on IBIS data large field of view,high angular resolution 1 GRB/month localised with 3 error radiusSpatial Distribution in Galactic Coordinates 37 GRBs localised by IBAS to date Distribution concentrated in direction of Galactic plane corresponding to maximum exposure timeSpectroscopic Redshifts050525a:z=0.606050502a:z=3.79031203 :z=0.106GRB 031203 Single peaked burst,duration 30s z=0.106,3rd nearest GRB Associated with Type Ic supernovaSazonov et al.,2019GRB 031203 contd.XMM follow-up-observed concentric ring-like structures centred on GRB location first detection of GRB X-ray“halo”Inferred high soft X-ray fluximplies X-Ray Flash Vaughan et al.2019 GRB 041219APeak flux 43 ph cm-2 s-1 greater than 98%of BATSE burstsT90=186s greater than all but a handful of BATSE burstsUnusual time structure-very little emission for 200s before pulse 1 startsEmission detected up to a few MeVMcBreen et al.A&A,2019GRB 041219A contd.keV(keV cm-2 s-1 keV-1)Spectrum of burst and sub-intervals well fit by Band model Also fit well by blackbody+power law model Black body contributes morestrongly in precursor than pulses 1 and 2Ryde,ApJ,2019S.McBreenPoster Session“Broadband spectrumOf GRB041219a”PulsePulse 2 2Pulse 1Pulse 1PrecursorPrecursorPolarisation with SPISPI can measure polarisation through multiple events in its SPI can measure polarisation through multiple events in its 19 detectors19 detectors0 0 180180 240240 300300 120120 6060 Polarisation of GRB 041219A Can compare real data to simulated polarised and unpolarised data to obtain polarisation fraction Q(modulation factor)is the maximum variation in azimuthal scattering probability for polarised photons Took all double events with total energy deposit 100Etot Can use spectral lag as GRB distance indicatorNorris et al.ApJ,2019GRB 040624 Spectral LagCCF peak at a spectrallag,of-2.3 0.5 s(high energy preceding low energy)GRB 040624 time profiles in25-50 keV band(blue)and 50-300 keV band(red)Recent GRBs detected by INTEGRAL -2.2 0.2 0.3 60GRB 050626 X,O?2.2 0.2 0.2 40GRB 050714A X,O 1.7 0.1 0.6 80GRB 051211B -1.1 0.2 0.3 100GRB 060114 -1.8 0.4 0.2 40GRB 060130 -1.6 0.3 0.2 78GRB 060204A AfterglowsX=XrayO=opticalPower law photon indexPeak flux(20-200 keV)(photons cm-2s-1)Duration (s)GRB -1.9 0.2 0.4 20GRB 051105B -N/A 0.1 25GRB 050922A X N/A 0.7 130GRB 050918INTEGRAL/SWIFT Peak Flux DistributionConclusions:IBAS provides accurate,fast localisations to the GRBcommunity-1 GRB per month INTEGRAL is providing new and interesting results onGRB prompt emission and enabling rapid afterglowfollow-ups to be carried out INTEGRALs SPI instrument may be used to detect polarisation in GRBs IBIS multi-band lightcurves allow for spectral lag(and luminosity)measurements to be made SWIFT detects more GRBs due to its larger field of view,however INTEGRAL detects many bursts at lower peak fluxesxiexie!xiexie!谢谢!谢谢!
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