INTEGRAL衛星の初期成果 海老沢 研 INTEGRAL Science Data Center Versoix, Switzerland Contents Introduction of the satellite Introduction of the instruments Status and performance of the instruments Early scientific results Current problems Prospects for future INTEGRAL satellite Launched on Oct 17, 2002 by Russian Proton rocket Covers 3 keV to ~10 MeV with three coded mask instruments Hard X-ray/gamm-ray imaging Gamma-ray spectroscopy INTEGRAL Orbit High eccentric orbit, 72 hour period Inclination 51.6° Perigee ~9,000 km, apogee ~150,000 km Two ground stations Goldstone (California) Redu (Belgium) REAL TIME OPERATION Gamma-ray burst monitor! INTEGRAL Detectors JEMX masks IBIS mask SPI IBIS detector JEMXdetectors IBIS • • (Imager on Board the Integral Satellite) Full imaging capability FWHM~12 arcmin Centroid accuracy ~arcmin • ISGRI (20-200 keV) 128x128 CdTe pixels Moderate energy resolution (~9%@100 keV) • PICSIT (100-6000 keV) 64x64 CsI pixels ISGRI (CdTe) PICSIT(CsI) Spectrometer SPI • Coded mask and 19 Ge detectors • Stirling cryocooler • Limited imaging capability(19 “pixels”) • BGO anti-coincidence detectors • High energy resolution ~2.2 keV@662 keV • Energy range 15 keV to 8 MeV • Anti Coincidence Sensor (ACS) GBD minotor! X-ray monitor JEMX • Two identical detectors • Imaging micro-strip gas chambers(90% Xenon + 10 % Methane) • Energy range 3-35 keV • ~30’’ angular resolution INTEGRAL prelaunch movie IBIS on-board sensitivity 3s, 105 sec exposure Ubertini et al.(2003) ISGRI Based on measured BGD, only statistical errors taken into account “Ultimate sensitivity” ~1mCrab @ 20-100 keV PICIST sources:Crab and Cyg X-1, GRB only? PICSIT SPI on-board sensitivity Roques et al. (2003) 10 mcrab 3s, 106 sec 1 mcrab SPI point source sensitivity is limited by confusion (~0.5 deg) JEMX on-board sensitivity Brandt et al. (2003) • Sensitivity limited by systematics • Ultimate sensitivity ~1mCrab Detectable sources “INTEGRAL reference catalog” Ebisawa et al. (2003) ~1000 known sources, ever brighter 1mCrab above 2 keV. Detectable sources •INTEGRAL has a large FOV •Eventually, all the sky will be fully covered •105 sec exposure over the sky •~700 sources with JEMX •~400 sources with ISGRI Ebisawa et al. (2003) Exposure map from Oct 2002 to Nov 2003 Green> 106 sec Blue >105 sec 3C273 Vela Cyg GC Crab LMC 2003 AO1 2004 AO2 Projects and targets Core program Galactic Center Deep Exposure (GCDE) Galactic Plane Scan (GPS) Vela region TOO observations for transient sources Projects and targets • Accepted general programs (A and B categories, besides TOO and GRB) – – – – – – – – – – AGN Galaxy Clusters Galactic diffuse G.C. SNR Binary Pulsar Stars Gamma-ray sources AO1 16 2 1 3 2 3 10 1 2 6 AO2 12 1 2 9 1 2 11 1 2 5 • Most AO1 observations completed, data are sent to PIs • Calibration and analysis software getting better… Early results Discovery of new sources (from GCDE, GPS) IAUC, Astronomer’s Telegram GRB detection GRB Coordinates Network (GCN) A&A special issue, 2003, vol 411, no1 75 letter papers (28 astrophysical papers) 5th INTEGRAL meeting in Feb 2004 (Munich) 244 abstracts submitted (including non-INTEGRAL papers) Some other publications… INTEGRAL Sources (http://isdc.unige.ch/~rodrigue/html/igrsources.html) 15 sources till Dec 2003 IGR J16316-4028 3EG J1631-4033 (?) IGR J16318-4848 Seen with ASCA in 1994, NH=3 x 1024 cm-2, prominent iron line IGR J16320-4751 NH=2.1 x 1023 cm-2, AX J1631.9-4752 IGR J16358-4726 NH=3.3 x 1023 cm-2, X-ray pulsations at 5850 +/-50 s IGRJ16479-4514 IGRJ17091-3624 1SAX J1709-36 IGRJ17391-3021 XTE J1739-302 IGRJ17456-2901 Sgr A*? or X-ray binary? IGRJ17464-3213 H1743-322,XTE J1746-322 IGRJ17544-2619 IGRJ17597-2201 XTE J1759-220 IGRJ18325-0756 IGRJ18483-0311 IGRJ18539+0727 IGRJ19140+098 All transient sources! IGR J16318-4848 (observed @50mCrab with INTEGRAL) Revnivtsev et al. (2003) ASCA 1994 ~1mCrab Walter et al. (2003) XMM and ISGRI Iron line dominate! Heavily absorbed X-ray binary transients! (probably high mass binaries like GX301-2) High energy imaging/spectra of binary sources SPI energy spectrum 308 -605 keV of Cyg X-1 20-50 84 -308 keV keV SPI image of the Cyg region Moderate resolution (~0.5 deg) imageup to ~600 keV! Bouchet et al. (2003) Cyg X-1 PCA HEXTE JEMX ISGRI SPI High quality spectra of bright sources from 3 keV to ~1 MeV! Pottschmidt et al. (2003) Bright X-ray binaries near GC b b l l l b ISGRI 20-40 keV ISGRI 40-60 keV High resolution (~10 arcmin) imaging up to ~100 keV Paizis et al. (2003) Early results – Gamma-ray bursts • 7 GRBs in the IBIS FOV (till Dec 2003) – Detected with INTEGRAL Burst Alert System (IBAS) – Alerts sent all over the world within ~10 sec – Position accuracy depends on the brightness, down to ~30” • SPI Anti-coincidence Sensor (ACS) alert (no position) ~1/day – sent to GRB Coordinates Network (GCN) GRBs detected with IBAS 4.4’ in 30sec! Mereghetti et al (2003) Error region and delay GRB detected with ACS Light curves Expected from BATSE Duration histogram von Kienlin et al. (2003) GRB energy spectra PICSIT ISGRI Malaguti et al. (2003) Good GRB energy spectra from 20 keV to 500 keV! GRB021125 GRB030501 ISGRI SPI Spectral variation SPI spectrum Beckman et al. (2003) Extragalactic sources •Many other bright AGNs detected (confirmed with real time Quick Look) Publication? •3C111 – radio galaxy at z=0.048 (~34 mCrab in the 20-40 keV band in August 2003 (Favre et al.) •Strong flares expected! (e.g. Blazers) •Normal galaxy? Clusters of Galaxies? 3C273 detected, expected spectrum (Courvoisier et al. 2003) Galactic center Belanger et al. (2003) 20 - 40 keV 40 - 100 keV Hard X-ray point source coincides with Sgr A* Sgr A*? X-ray binary? Strong et al. (2003) Galactic diffuse emission • Preliminery results •Consitent with previous XTE, OSSE observation GC=33deg •A rumor says… •Contrubution of point sources at ~100 keV dominant than previous estimates? •Not so much Galactic “diffuse” emission at ~100 keV? L=33deg Galactic center 511 keV line Knodlseder et al. (2003) Symmetric diffuse distribution around GC Annihilation fountain (claimed by OSSE) not confirmed Russian data! Current problems • Calibration – Background estimation, subtraction – Spectral response • Analysis technique – Currently, deconvolution is made for each pointing (~30 min), deconvolved images and spectra combined – Photons have to be accumulated for longer periods! – Deconvolution at once from many (~1000) pointings – Memory and CPU serious problems… • Data structure, software issues – Unique data structure, incompatibility with widely-used analysis system, difficult to handle “event” data – No good portability of data/software Future prospects • Detection of more gamma-ray lines expected – SNR, Point sources • • • • Annihilation line from point sources? Dim sources down to 1 mCrab at >50 keV? High quality spectra of dim sources up to ~1 MeV Short transients? – Gamma-ray/X-ray “flush” events • Fast pulsars? – Hard X-ray study of millisecond pulsars
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