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Spectroscopy of the Stellar Wind in the Cygnus X-1 System

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Spectroscopy of the Stellar Wind in the Cygnus X-1 System Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Spectroscopy of the stellar wind in the Cygnus X-1 system Ivica Miˇskoviˇcov´a⋆, Manfred Hanke⋆ J. Wilms⋆, M. A. Nowak, K. Pottschmidt, N. S. Schulz ⋆ Dr. Remeis Observatory, Bamberg Erlangen Centre for Astroparticle Physics University Erlangen-Nuremberg, Germany Black Hole Universe September 22, 2010 Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Outline of the talk 1 Introduction Accretion in X-ray Binaries Stellar wind 2 Cygnus X-1 Cygnus X-1 and its companion HDE 226868 Stellar wind in the Cygnus X-1 Source states Chandra observations 3 Data and data analysis Instruments ObsID 3815, φ ≈ 0.76 4 Light Curves and Dipping Light curves 5 Absorption lines 6 Summary Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Accretion in X-ray Binaries stellar wind accretion in High Mass X-ray Binaries (HMXB) accretion disk accretion in Low Mass X-ray Binaries (LMXB) efficient energy release, X-ray luminosities ∼ 1038 erg/s Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Stellar wind of HMXBs hot, O or early B stars: winds driven by absorption lines −6 very strong: mass loss rate ∼ 10 M⊙/year Theory: two components of the wind: cool dense clumps embedded by hot photoionized gas (Castor, Abbot, Klein, 1975; Sako et al. 2002) Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Stellar wind of HMXBs hot, O or early B stars: winds driven by absorption lines −6 very strong: mass loss rate ∼ 10 M⊙/year Theory: two components of the wind: cool dense clumps embedded by hot photoionized gas (Castor, Abbot, Klein, 1975; Sako et al. 2002) wind structure can be probed directly by Chandra high-resolution spectroscopy (with bright sources like Cyg X-1) Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary The high-mass X-ray binary system Cygnus X-1 HDE 226868 O9.7 Iab supergiant M⋆ = 18 M⊙ L⋆ = 250 000 L⊙ black hole LX ≈ 10 000 L⊙ Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Focused stellar wind in the system 0.2 0.3 0.4 0.1 0.7 0.5 0.0 0.8 0.6 Friend & Castor (1982) 0.9 0.5 1.0 phi = / yr sr] "focused sun wind" M −6 [10 Ω Cyg HDE 226868 X−1 0 0.2 0.4 0.6 mass loss rate dM/dt/d 0 50 100 150 (M.Hanke,2009) angle θ from binary axis [degrees] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Hard and Soft State of the Cygnus X-1 hard or soft 20 50 101997 100 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 RXTE−ASM 1.5−12 keV rate [cps] In the low/hard state: hard powerlaw spectrum, low soft X-ray luminosity, high radio flux In the high/soft state: thermal spectral component high soft X-ray luminosity, low radio emission. Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Chandra observations of Cygnus X-1 ◦ hard → soft state —TEmode, ··· CC mode i ≈ 35 Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Goals and aims of the research We focus on High Mass X-ray Binaries, especially Cyg X-1 strong and focused stellar wind and its properties source states transitions understanding of the accretion process by detailed study of photoionization of material (high X-ray luminosity) spectral analysis of absorption lines Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Chandra High Energy Transmission Grating (HETG) two sets of gratings: the High and the Medium Energy Grating (HEG and MEG) Grating equation: m.λ = p.sinβ Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Data reduction with CIAO 4.2 and order-sorting problem Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Data reduction with CIAO 4.2 and order-sorting problem Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Data reduction with CIAO 4.2 and order-sorting problem Solution: tg resolve events ⇒ osipfile=”none”, osip lo and osip hi Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary ObsID 3815 - light curve Orbital phase of the Cyg X−1 0.7 0.72 0.74 0.76 0.78 0.8 0.82 Count rate [cps] 50 100 150 200 0.4 0.6 0.8 (0.5−1.5)/(1.5−3) 1 2 (0.5−1.5)/(3−10) 1 2 3 (1.5−3)/(3−10) 0 10 20 30 40 50 60 Time since MJD 52702.658 [ks] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Telemetry saturation Fractional exposure CCD 4 0 0.5 1 CCD 5 0 0.5 1 CCD 6 0 0.5 1 CCD 7 0 0.5 1 CCD 8 0 0.5 1 CCD 9 0 0.5 1 0 10 20 30 40 50 Time since MJD 52702.665 [ks] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary ObsID 3815 - corrected light curve Orbital phase of the Cyg X−1 0.7 0.72 0.74 0.76 0.78 0.8 0.82 Count rate [cps] 50 100 150 200 0.4 0.6 0.8 (0.5−1.5)/(1.5−3) 1 2 (0.5−1.5)/(3−10) 1 2 3 (1.5−3)/(3−10) 0 10 20 30 40 50 60 Time since MJD 52702.658 [ks] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary ObsID 3815 - corrected light curve Orbital phase of the Cyg X−1 0.7 0.72 0.74 0.76 0.78 0.8 0.82 Count rate [cps] 50 100 150 200 0.4 0.6 0.8 (0.5−1.5)/(1.5−3) 1 2 (0.5−1.5)/(3−10) 1 2 3 (1.5−3)/(3−10) 0 10 20 30 40 50 60 Time since MJD 52702.665 [ks] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Compared Chandra observations of Cygnus X-1 Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Light curves of Cyg X-1 at prominent phases 500 500 ObsID 3814 ObsID 8525 ObsID 9847 ObsID 11044 200 2003-04-19/20 2008-04-18/19 2008-04-19 2010-01-14 200 100 100 50 50 20 ObsID 3815 20 2003-03-04/05 0.5–10 keV count rate (c/s) 10 10 8 8 58 ks 48 ks 30 ks 19 ks 30 ks 4 4 2 2 1 1 0.5 0.5 0.3 0.3 (0.5–3 keV) / (3–100.2 keV) 0.2 0.7 0.75 0.8 -0.05 0 0.05 0.2 0.5 0.55 Orbital phase φ (At φ=0, Cyg X-1 is only seen through the densest part of the donor’s stellar wind.) φ≈0: violent absorption dips dipping occurs already at φ≈0.7 and has not ceased at φ≈0.2 φ≈0.5: totally free of dips! Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary ObsID 3815 - Color-color diagram Orbital phase of the Cyg X−1 0.7 0.72 0.74 0.76 0.78 0.8 0.82 0.5 1 1.5 2 (0.5−1.5)/(3−10) Ratio (1.5−3 keV)/(3−10 keV) 1 1.5 2 2.5 3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 Ratio (0.5−1.5 keV)/(1.5−3 keV) Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Color-color diagrams - comparison 3.5 ObsID 3815 ObsID 11044 3 2.5 2 1.5 1 0.5 2 1.5 ObsID 3814 1 ObsID 8525 ObsID 9847 0.5 0 “Hard” (1.5–3 keV rate) / (3–10 keV rate)0 Softness Ratio 0.2 0.4 0.6 0.8 0 0.2 0.4 0.6 0.8 “Soft” (0.5–1.5 keV rate) / (1.5–3 keV rate) Softness Ratio Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Absorption lines Spectrum absorption lines χ −5 0 5 2 4 6 8 10 12 14 Wavelength [Å] Ivica Miˇskoviˇcov´a:Spectroscopy of the stellar wind in the Cyg X-1 Introduction Cygnus X-1 Data and data analysis Light Curves and Dipping Absorption lines Summary Absorption and P Cygni profiles of Si xiv, Mg xii, Ne x Wavelength [A]˚ Wavelength [A]˚ Wavelength [A]˚ 6.14 6.16 6.18 6.2 6.22 8.4 8.45 12.05 12.1 12.15 12.2 2.2 2 3 2 1.8 1.8 2.5 1.6 1.6 2 1.4 1.4 1.5 1.2 1.2 1 1 1 Data /0.8 Model (Continuum) + offset -2000 -1000 0 1000 2000 -2000 -1000 0 1000 2000 -2000 -1000 0 1000 2000 Velocity (Si xiv α) [km/s] Velocity (Mg xii α) [km/s] Velocity (Ne x α) [km/s] φ≈0: strong absorption lines, vrad≈0 φ≈0.5: P Cygni profiles: strong emission at vrad≈0 and weak absorption tail blueshifted by ∼ 500 − 1 000 km/s ⇒
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