Gamma-Ray Bursts Gamma-Ray Bursts observed with observed with

INTEGRAL and XMM-INTEGRAL and XMM-NewtonNewton

Sinead McGlynn

School of Physics

University College Dublin

What is a gamma ray burst?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?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 SatelliteINTEGRAL 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 INTEGRAL OrbitOrbit

IBIS mask

JEM-X masks

IBIS detector

JEM-X detectors SPI

Optical Monitor

INTEGRAL DetectorsINTEGRAL Detectors

Coded MasksCoded 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

~2.2 keV@ 662 keV• energy range 15 keV to 8

MeV

Spectrometer SPISpectrometer SPI

ISGRI (CdTe)

PICsIT(CsI)

• Full imaging capability - FWHM ~ 12 arcmin

• Fully coded field of view - 9° x 9° • ISGRI (20-200 keV) - 128x128

CdTe pixels moderate energy resolution (~9% at 100keV)

IBISIBIS :Imager on Board the Imager on Board the

INTEGRAL SatelliteINTEGRAL Satellite

detectors

mask

IBAS = Integral Burst Alert SystemIBAS = 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 daysLight curve available after 10 minNo position

http://ibas.mi.iasf.cnr.it

XMM-NewtonXMM-Newton

• XMM=Xray MultiMirror• launched December

1999• 3 X-ray nested mirrors

which collect X-rays• detectors at focal point

of mirrors• energy range 0.1-

15keV

• detects afterglow emission from GRBs

detectors

mirrors

Recent Recent GRBs detected by GRBs detected by INTEGRALINTEGRAL

-2.20.360GRB 050626

X, O?2.20.240GRB 050714A

X, O1.720.680GRB 051211B

-1.120.3100GRB 060114

-1.80.240GRB 060130

-1.60.278GRB 060204A

Afterglows

X=Xray

O=optical

Power law

photon index

Peak flux

(20-200 keV)

(photons cm-2s-1)

Duration

(s)GRB

-1.970.420GRB 051105B

-N/A0.125GRB 050922A

XN/A0.7130GRB 050918

• Lasted 52s, OT detected, followed up by XMM

• SPI: photon index = -1.47± 0.60, Flux 0.57 ph/cm²/s

GRB 040106:GRB 040106:Moran et al, A&A 2005

• GRB location distributed within 12 s • XMM ToO began 5 hours after GRB • flattest spectrum so far

= -1.47 ± 0.02

NH = 7.4 ± 0.9 x 1020 cm-2

(consistent with Galactic value)

Fx(2-10keV) =

1.1x10-12 erg/cm2/s

PN

MOS1 & MOS2

XMM ObservationsXMM Observations

GRB 040223GRB 040223

• Weak GRB• Large X-ray column density NH ~1022

• Spectral lag of 2.2 seconds gives z = 0.1

McGlynn et al, 2005 astro-ph/0505349

Lightcurve

(15-40 [blue]

& 40-200 [red] keV)

GRB041218GRB041218

• 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 041219AGRB 041219A• 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 041219aSpectra of GRB 041219a

• 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: GRB050904 (/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:CONCLUSIONS: