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INTEGRAL All-Sky Survey: Deep inside Galaxy and beyond. R.Krivonos, M.Revnivtsev, S.Tsygankov, A. Lutovinov, E.Churazov, R.Sunyaev MPA, Garching, Germany IKI, Moscow, Russia Excellence Cluster Universe, Garching, Germany. INTEGRAL/IBIS
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INTEGRAL All-Sky Survey: Deep inside Galaxy and beyond R.Krivonos, M.Revnivtsev, S.Tsygankov, A. Lutovinov, E.Churazov, R.Sunyaev MPA, Garching, Germany IKI, Moscow, Russia Excellence Cluster Universe, Garching, Germany
INTEGRAL/IBIS All-sky survey (Krivonos et. al., 2007, current state) ~600 detections: ~45% Galactic ~40% ExtraGal. ~15% Unident. SWIFT/BAT 36Month All-sky survey (Cusumano et. Al., 2009) ~1000 detections: ~20% Galactic ~55% ExtraGal. ~25% Unident.
INTEGRAL/IBIS exposure map SWIFT/BAT sensitivity map: (Cusumano et. al., 2009)
Source-free Sensitivity is strongly limited by systematic noise Galactic Center region 20 Msec 17-60 keV INTEGRAL/IBIS
Having a large exposure accumulated in Galactic Plane, the survey sensitivity is significantly limited by systematic noise.The main constrains: Source projection model Source interplay in Galactic Center Galactic Background
1) Source projection model Source removal is not perfect, the residuals on detector can be 0.3-0.5% of the source flux
Sco X-1 7σ excess
1) Source projection model Residuals: Crab field: ~10 mCrab Sco X-1 field: ~5-7 mCrab GC region: ~1-0.5 mCrab Status: fixed at some sufficient level (mask pattern, screws, NOMEX support structure, etc.) Future:can be improved (pixel-to-pixel gain variations, dead time)
2) Source self-influence in GC …due to detector shared area between sources, and periodic mask Status: fixed at some sufficient level (correct solution cannot be found) Future:can not be significantly improved source subtraction order significantly change sky background: 4 Ms
2) Source self-influence in GC The insuperable difficulties in GC survey are detector shared area between sources, and periodic mask pattern (e.g. Swift/BAT has no such constrain)
3) Galactic X-Ray Background 150-200 mCrab / FOV / 17-60 keV
Galactic Ridge intoduces at least 15-20% of systematic noise 300 ksec deep field of NGC4151 in staring mode +”Ridge like illumination” Status: fixed at some sufficient level (more efficient on special observing pattern) Future:can not be significantly improved
Summary (not final) Source projection model: fixed/can be improved Source interplay in GC: fixed/cannot be improved Galactic Background: fixed/cannot be improved Generally we can’t significantly further improve IBIS/ISGRI imaging system, but we can remove systematic residuals from the reconstructed sky
Non-parametric sky background approximation (wavelets) 300 ksec deep field of NGC4151 in staring mode Coded-mask can reconstruct on sky only point source, the other stuff is sky background (flat) and systematic residuals. The idea: use spatial freq. information to remove systematic noise
Swift/XRT 2 days ago 300 ksec deep field of NGC4151 in staring mode SKY=Deconvolve(DET-SRCs) + SRCs SKY=WV(Deconvolve(DET-SRCs)) + SRCs Systematic noise (~30%) is removed Sensitivity is limited by pure statistics only! Immediate result: New source IGR J11203+4531 was detected (rev. 0074-0076)
5Ms deep field of 3C273 S/N distribution is consistent with Gaussian σ=1 2 pix at -4.7σ (1.5 expected for total 557096 pix)
Galactic Center region 20 Msec 17-60 keV
Galactic Center region 20 Msec 17-60 keV
Survey: statitsics (in process) (http://hea.iki.rssi.ru/integral/catalog) • 214 (144) AGN (statistically clear sample: N=115) • 80 (77) HMXB • 92 (89) LMXB • 39 (26) CV • 3 Clusters • and others… Total: 562 at >5σ Galactic: 239 Extragalactic: 217 Unidentified: 107 new hard X-Ray sources: IGR J18151-1052 0.54+/-0.10 mCrab HMXB IGR J17009+3559 0.96+/-0.20 mCrabAGN? IGR J11203+4531 3.68+/-0.58 mCrab … … Atels 2170,2193
Revnivtsev et al. 2008 Survey: galactic LF New ultra-deep Galactic survey probes the low end of the LF: Llim=4e34 erg/s @8.5 kpc
Survey: LogN-LogS Extragalactic: 115 AGNs used Slope: -1.5+/-0.1
Volume density excess of nearby (<70 Mpc) 40 AGNs: (INTEGRAL survey) ~5,000 IR galaxies: (IRAS PSCz survey) Convolved with INTEGRAL FOV
b= bAGN = 1.0 bAGN = 0.80 ± 0.13 X-Ray AGN bias factor We use IRAS PSCz survey as matter tracer ( bIR≈1 ) Krivonos et al. in prep. => AGNs – good matter tracers on 10-70 Mpc scale => SMBH activity independent from density of galaxies
Summary • INTEGRAL ultra-deep Galactic survey and excellent SWIFT/BAT extragalactic survey are great couple to complement each other in studying the hard X-ray sky • GC limited by ~20% systematics. We reduced systematic noise by ~30% and now sensitivity grows with exposure closely to the ideal case Flim~T-1/2 • Sensitivity of the INTEGRAL extragalactic survey is limited by pure statistics only. Ultra-deep extragalactic survey is possible. • 5σ Limiting flux in GC (20 Ms) is 0.3 mCrab(4.7e-12 erg/s/cm2) • INTEGRAL ultra-deep Galactic survey probes the low end of the LF: Llim=4e34 erg/s @8.5 kpc