Gamma-Ray Bursts observed with INTEGRAL and XMM- Newton Sinead McGlynn School of Physics University College Dublin

What is a gamma ray burst? emission (over seconds) of a large number of gamma rays cosmological origin lightcurves vary in appearance cumulative lightcurves are simple

What causes a gamma ray burst? some occur in star- forming regions in a galaxy caused by the collapse of a massive star to a black hole over time, afterglows are detected (X,O,R,IR) gamma rays emitted in beamed jets

launched on October 17, 2002 by Russian Proton rocket covers 3 keV to ~8 MeV with three coded mask instruments hard X- & gamma-ray imaging gamma-ray spectroscopy INTEGRAL Satellite

high eccentric orbit, 72 hour period inclination 51.6° Perigee ~10,000 km, Apogee ~150,000 km Two ground stations Goldstone (California) Redu (Belgium) REAL TIME OPERATION Gamma-ray burst monitor INTEGRAL Orbit

IBIS mask JEM-X masks IBIS detector JEM-X detectors SPI Optical Monitor INTEGRAL Detectors INTEGRAL Detectors

Coded Masks array of opaque & transparent elements can reconstruct source position from pattern background and source can be measured simultaneously

coded mask and 19 Ge detectors Stirling cryocooler fully coded field of view 16° corner to corner limited imaging capability 500kg of BGO anti- coincidence shielding High energy resolution ~ keV energy range 15 keV to 8 MeV Spectrometer SPI

ISGRI (CdTe) PICsIT(CsI) Full imaging capability - FWHM ~ 12 arcmin Fully coded field of view - 9° x 9° ISGRI ( keV) - 128x128 CdTe pixels moderate energy resolution (~9% at 100keV) IBIS Imager on Board the IBIS :Imager on Board the INTEGRAL Satellite INTEGRAL Satellite detectors mask

IBAS = Integral Burst Alert System IBIS : GRBs in FoV ~ 1 GRB/month localized at 3 arcmin. Positions distributed in real time within seconds SPI: Anticoincidence Shield ~ 1 GRB/2-3 days Light curve available after 10 min No position

XMM-Newton XMM=Xray MultiMirror launched December X-ray nested mirrors which collect X-rays detectors at focal point of mirrors energy range keV detects afterglow emission from GRBs detectors mirrors

Recent GRBs detected by INTEGRAL GRB X, O? GRB A X, O GRB B GRB GRB GRB A Afterglows X=Xray O=optical Power law photon index Peak flux ( keV) (photons cm -2 s -1 ) Duration (s) GRB GRB B -N/A0.125GRB A XN/A0.7130GRB

Lasted 52s, OT detected, followed up by XMM SPI: photon index = -1.47± 0.60, Flux 0.57 ph/cm²/s GRB : Moran et al, A&A 2005

GRB location distributed within 12 s XMM ToO began 5 hours after GRB flattest spectrum so far  = ± 0.02 N H = 7.4 ± 0.9 x cm -2 (consistent with Galactic value) F x (2-10keV) = 1.1 x erg/cm 2 /s PN MOS1 & MOS2 XMM Observations

GRB Weak GRB Large X-ray column density N H ~10 22 Spectral lag of 2.2 seconds gives z = 0.1 McGlynn et al, 2005 astro-ph/ Lightcurve (15-40 [blue] & [red] keV)

GRB One of the strongest bursts seen by INTEGRAL fit by a Band model with break energy = 80 keV being analysed for post burst emission

GRB A Extremely intense burst Peak flux of 20 photons/cm/s Unusual time structure; very little emission for 200s before pulse 1 starts Emission up to a few MeV McBreen et al, A&A 2006

Spectra of GRB a Fluxes obtained from RAPTOR (optical),PAIRITEL (IR), Swift & INTEGRAL (gamma) Multi wavelength observations show that optical emission is correlated to gamma ray emission A-D: GRB041219a E: GRB (/1000) optical  ray IR

INTEGRAL is providing FAST and PRECISE localizations for ~1 GRB/month INTEGRAL and XMM yield interesting results on GRBs and their afterglows SWIFT will localize more bursts than INTEGRAL thanks to its larger field of view BUT… INTEGRAL will detect the faintest (and possibly most distant ?) bursts CONCLUSIONS: