Survey of the Milky Way and nearby galaxies
Survey of the Milky Way and nearby galaxies in hard X- and gamma- rays Lutovinov A. Revnivtsev M. , Tsygankov S. , Krivonos R. , Space Research Institute (Moscow) FINCA, University of Oulu (Finland) University of Berkley (USA)
INTEGRAL observatory Launched 17 Oct 2002 (PROTON) orbit - 72 h perigee ~ 9000 km apogee ~ 153000 km Spectrometer SPI (15 ke. V-8 Me. V) (E/d. E~500) Gamma-telescope IBIS (20 ke. V-10 Me. V (200 ke. V) , ~12´)
Large Magellanic Cloud LMC was observed many times in 2003 and 2009 -2012 Main goal – registration of the 44 Ti lines due to a radioactive decay Discovery lines at 67. 9 and 78. 4 ke. V (Grebenev et al. Nature 2012) Total exposure ~7 Msec (4. 8 Msec dead-time corrected)
Inhomogeneous of the Local Universe at low fluxes the curve of AGN counts in the 3 C 273 region is in good agreement with the same curve averaged over the entire sky 3 C 273 (14) excess of bright objects, with most of them having low redshifts and being closer than ≈70 Mpc. LMC (4) Lutovinov et al. (2012) Krivonos et al. (2007)
High-mass X-ray Binaries Universal form a~1. 6 Grimm et al. (2003) Postnov (2003) Shtykovskiy, Gilfanov (2005) LMC, XMM-Newton Lutovinov et al. (2012) LMC, INTEGRAL Indication of a flatness of LFat low luminosities Shtykovskiy, Gilfanov (2007) Is the LF of HMXBs really universal? SMC, XMM-Newton Only study of MW can help to answer
Milky Way
9 years Galactic plane survey with INTEGRAL Dec 2002 – Jan 2011, Total – 402 sources on the average total exposure 132 Msec, map, galactic – 252 (108 LMXBs, 75 peak sensitivity in 17 -60 ke. V HMXBs, 36 CVs), Extragalactic – 2. 9 x 10 -12 erg/s/cm 2 (0. 2 m. Crab) 115 (112 AGNs, 3 GCs) Identification completeness – 91% thanks to efforts of number of groups: Masetti+, Burenin+, Bikmaev+, Nespoli+, Chaty+, Bodaghee+ Rodrigues+, Tomsick+, Landi+, Malizia+, and many others Krivonos et al. (2012)
Complete, flux-limited sample of HMXBs |b|<5º Only sources with known distances and spectral class Exclude BH, gamma-loud binaries (Cyg X-1, Cyg X-3, LSI +61 303, etc) Exclude transient sources criteria Fp/Fmean > 0. 5 Flux limited 0. 7 m. Crab (10 -11 erg/s/cm 2) Final sample includes 37 sources Wind-fed binaries with NS
Majority of sources have SG companions
INTEGRAL view through the whole Galaxy Real sensitivity: 2 x 1035 erg/s Limited flux 0. 7 m. Crab (10 -11 erg/s/cm 2) 2 x 1035 erg/s The Galaxy was divided into 5 rings 0 -2, 2 -5, 5 -8, 8 -11 and 11 -14 kpc Key tasks: 1) LF and 2) Surface density
Luminosity function > 2 x 1035 erg/s completeness 13 kpc > 2 x 1034 erg/s completeness 4. 1 kpc Cash (1979)
Density distribution of the HMXBs vs SFR Systematic Δ=20% N≈5 x 10 -2 SFR/SFRΘ Guesten & Mezger 1982; Lyne, Manchester, & Taylor 1985; Chiappini, Matteucci, & Romano 2001
Simple model for the wind accretion NS Luminosity of NS depends on: Companion mass Orbital period
Formation and evolution Mc rises Our statistically complete fluxlimited sample provides clues – what determines the HMXB population 1) Porb distribution 2) Mc distribution mi n. M c ~7 -8 M Su n
d. N/d. Mc ~Mc-2. 35 (Salpeter) d. N/dlog. P = const (Bhattacharia, Ghosh, 2012) Orbital parameters 90% completeness Lutovinov et al. (2013)
SFXT (Supergiant Fast X-ray Transients) Flux t ~ hours Fm/Fp~104 -5 Time, days
SFXT (outbursts mechanisms) Clumpy wind (Walter et al. 2006, Sidoli et al. 2011) Inhibition of the accretion (Grebenev & Sunyaev 2007, Bozzo et al. 2008) Flaring activity due to transition from (stable) radiative cooling to (unstable) Compton cooling
Future surveys, predictions Spectrum XG (Russia+Germany) Launch 2014 Large area 1. 18 x 10 -13 erg/s/cm 2 ~130 persistent HMXB in MW
Conclusions 1) INTEGRAL: first complete survey of HMXB in Milky Way and LMC (absorption ignorant) 2) Inhomogeneous of the Local Universe 3) Dominance of SG systems among persistent sources! 4) Curved shape of HMXB LF 5) Surface density distribution - > SFR 6) Clues to mechanism of SFXT outbursts
Exclude transient sources criteria Fp/Fmean > 0. 5
Vertical distribution of HMXBs h≈85 -90 pc Distribution of massive stars WR ~45 pc (Conti & Vacca 1990) OB associations ~30 pc (Bronfman et al. 2000) Open clusters ~50 pc (Joshi 2005) Kinematical age } System velocity of HMXBs (Kaper et al. 1997; Hutoff & Kaper 2002
- Slides: 22