Status of the INTEGRAL satellite Ken Ebisawa (INTEGRAL Science Data Center, NASA/GSFC) INTErnational Gamma-RAy Laboratory � ESA mission (decided in 1993, part of ESA Horizon 2000) � With US participation � Gamma-ray imager (IBIS) and Spectrometer (SPI), and X-ray monitor cameras (JEMX) � Coded mask instruments � Covers 2 keV to 8 MeV � Also optical monitor camera (OMC) � High position resolution with IBIS(~12 arcmin FWHM) � with medium energy resolution � High spectral resolution with SPI (E/ ∆ E~500) � with low spatial resolution � Launched Oct. 17, 2002 by Proton rocket from Baikonur
Masks IBIS JEMX Detectors SPI
INTEGRAL orbit � High eccentric 72 hour orbit � Inclination 51.6 ˚ � Perigee ~9,000 km, Apogee ~150,000 km � Ground stations � Goldstone (California) � Redu (Belgium) � Real time operation � GRB alerts! Imager IBIS Mask � Same mask, two detector layers Full imaging capability � FWHM~12 arcmin � � ISGRI (20-200 keV) 128x128 CdTe pixels � � PICSIT (100-6000 keV) 64x64 CsI pixels � CdTe layer (ISGRI) CsI layer (PICIST)
Spectrometer SPI � Coded mask and 19 Ge detectors � Stirling cryocooler � Limited imaging capability(19 “pixels”) � BGO anti-coincidence detectors � Energy resoluvtion ~2.2 keV@662 keV � Energy range 15 keV to 8 MeV X-ray monitor JEMX � Two identical detectors � Imaging micro-strip gas chambers(90% Xenon + 10 % Methane) � Energy range 3-35 keV � ~30’’ angular resolution
Sensitivity � Limited by systematics � 1mCrab at 100 keV, 0.1 Crab at 1 MeV (for continuum, point source) � Excellent line sensitivity for diffuse sources with SPI Large FOV IBIS partially coded FOV (30 ˚ x30 ˚ ) IBIS fully coded FOV (9 ˚ x9 ˚ ) JEMX SPI fully coded FOV
Dithering and “ Sceince Windows ” � SPI imaging capability is limited → “dithering” observation � Observation is split into many pointings (“Science Windows”) � Each ScW is ~30 minutes Operation � INTEGRAL Science Operation Center (ISOC) takes care of the planning � Mission Operation Center (MOC) will send commands and receive telemetry � ISDC takes care of downstream � Receiving telemetry � Conversion to FITS � Develop analysis software for users � Distribution of the data and software to INTEGRAL users � Archive data, and user support
Oct 17, 2002 INTEGRAL observations � ”Core” observation program � Galactic Plane Scan � Galactic Center Deep Exposure � Vela region � Transient sources (TOO) � Guest Observer program � AO1 program being performed � Gamma-ray bursts (IBAS) → GCN � Quick Look Analysis and alerts → IAUC
Galactic Plane Survey simulation � Total ~2M sec with ~1700 Pointings � Covers the entire plane with |b|<25 ˚ � Carried out once per every week for over ~60 ˚ in longitude Galactic Center Deep Exposure simulation � Total ~4 M sec, ~1000 pointings � |l|< 30 ˚ , |b|<30 ˚
Other core programs (~3 Msec) � Vela region � Mrk 501 � GX339-4 � 1E 1740-2942 � GRS1915+105 � GRO J1655-40 � Cyg X-1, Cyg X-3 � SN Ia, II, classical nova � new X/gamma-transients Guest Observer program � AO1 in 2001 February � Completely open to the world � Total ~110 proposals accepted � ESA countries, USA, Russia, Japan…. � Data will be public in one year (as well as the core program data)
INTEGRAL Burst Alert System (IBAS) � Near real time distribution of the positions of GRBs detected by INTEGRAL � Fully automated and checks the real-time telemetry � Search for GRBs with different time scales � If confirmed, alerts are automatically sent to GRB Coordinates Network (GCN) Quick Look Analysis System � Automated, all the ISGR and JEMX data are checked for bright new transients, or significantly variable sources � If confirmed, IAU Circ. will be issued � Sensitivity ~ 50 mCrab � QLA available a few hours (processing time) after the data acquisition
Status of the instruments � JEMX radiation damage � Several anodes were lost � High voltage reduced � Bombardment of heavy ions? � Only one is operation, the other spare � The first SPI annealing successful � Higher background than expected? � Background characteristics being studied Cyg X-1 images JEMX mosaic SPI ISGR
Cyg X-1 energy spectra � Spectral shape agrees with XTE reasonably well � Normalization does not match yet Crab pulsation (with ISGRI) � Time resolution ~60 µ sec
Gamma-ray bursts SPI image and spectrum Of GRB030227 GRB021125 by SPI ACS SPI raw spectrum (particle events)
Galactic Plane Scan (Cen region with ISGR) New sources � IGRJ16318-4848 � Detected in the ASCA archives! � large absorption � Extremely strong Fe line
For potential users … � AO2 will be announced in med/late 2003 � Archives will start early 2004 � All the data will be public � User supports from ISDC and INTEGRAL GOF
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