The 7-year view of the accreting X-ray binaries with INTEGRAL R.Krivonos, M.Revnivtsev, S.Tsygankov, E.Churazov, R.Sunyaev MPA Garching, Germany; IKI, Moscow, Russia

Galactic Center region, 20 Ms, keV Limiting flux ~0.26 mCrab 3.7e-12 erg/s/cm 2 Luminosity 4e+34 erg/s at the distance of GC The Milky Way is a unique galaxy where we can detect X- ray objects with the lowest possible luminosities.

Stellar density field Galactic Center region, 20 Ms, keV

Low-Massive X-ray Binaries in Bulge Revnivtsev et al., 2008

Low-Massive X-ray Binaries in Bulge d log N / d log L = / at log(L) < 37 Break in dM/dT distribution? Change in Lx – dM/dT relation? Recent: the break is due to different classes of companion stars: Gilfanov 2004 Revnivtsev et al., 2010

Galactic ridge X-ray emission with INTEGRAL It is shown that the Ridge is due to point sources at energies <10 keV (Revnivtsev et al. 2006, 2007, 2008, 2009)` What is in hard X-rays? Cataclysmic Variables: first approach

INTEGRAL view of the GRXE NIR contours Krivonos et al. 2006, 2009

Galactic ridge emission in hard X-rays consists of emission of millions of CVs! Shape of cutoff average mass of WDs ~ M sun INTEGRAL RXTE

The dominant class of INTEGRAL CV is intermediate polars Revnivtsev et al., 2008 INTEGRAL provides one of the largest unbiased sample of luminous intermediate polars existing today (37 in the 7-year survey) The survey is serendipitous with respect to CVs Cataclysmic Variables INTEGRAL Cataclysmic Variables: second approach

Cataclysmic Variables Scale height of Galactic disk population is 130 (+90-50) kpc

Luminosity function of hard X-ray emitting CVs only from INTEGRAL all sky survey! Revnivtsev et al Cumulative emissivity of CVs in keV Ridge value in keV INTEGRAL points RXTE points

Revnivtsev et al. 2008

Density of HMXBs In the Galactic plane INTEGRAL survey Simple toy model Lutovinov et al. 2005, 2007

The position of spiral arms (ignored) Shtykovskiy & Gilfanov 2007

Method: Integrate the galactic disk model with a given luminosity function, given survey sensitivity map, and measure the probability to have the observed distribution of sources.

-- measured -- not ID -- predicted High-Massive X-ray Binaries distribution over the Galactic longitude Crux Carina Norma Cyg Sgr

Disk without hole

r_disk = 2.2 ( ) kpc Disk size

dN/dL ~L Probing the LF (single) slope over Log(L) Gamma Gamma = 1.3 ( ) Voss & Ajello 2010

Maximum Likelihood HMXB Luminosity Function delta Likelihood < 1.0 Log

Unrealistic LF shape: Overprediction at low luminosities Log

Unrealistic LF shape: Underprediction at low luminosities Like “Propeller effect” Log

dN/dL~L^1.5 Absolutely unrealistic LF shape: Log

The perfect sky imaging with IBIS/ISGRI is possible: IKI/RSDC MPA Concluding remarks (1) 7-year Galactic Bulge Map Galactic Plane Survey Galactic Bulge Monitoring Catalog of sources with spectra and lightcurves INTEGRAL/IBIS 7-year All-Sky Hard X-Ray Survey. Part I: Image Reconstruction A&A (arXiv: ) INTEGRAL/IBIS 7-year All-Sky Hard X-Ray Survey. Part II: Catalog of Sources A&A (arXiv: )

Flat end of luminosity function at Log (L) < 37 The cumulative angular distribution in the Galactic center region traces the cumulative number of stars (bulge and nuclear stellar disk components) Concluding remarks (2) LMXB in Bulge => Break in dM/dT distribution? => Change in Lx – dM/dT relation? => Different classes of companions

The scale height of the Galactic disk 130 (+90-50) kpc Luminosity Function Luminosity density is consistent with that measured from unresolved emission (“Rigde”) Concluding remarks (3) Cataclysmic Variables

Spatial distribution of HMXB allows one to constrain lower and upper limits for luminosity function regardless distance information Probe of flattening at Log (L) < 34 “Propeller effect” Concluding remarks (4) HMXB