1 / 21

The Broad Iron Line Profile of XTE J1650-500

The Broad Iron Line Profile of XTE J1650-500. DOM WALTON IoA, Cambridge, UK In collaboration with Rubens Reis, Ed Cackett, Jon Miller and Andy Fabian. Berlin: 2011. BLACK HOLE ACCRETION.  f .  f . . . Dom Walton. Berlin: 2011. AGN SPECTRA. 1H 0707-495 - Zoghbi et al. (2010)

fifi
Download Presentation

The Broad Iron Line Profile of XTE J1650-500

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Broad Iron Line Profile of XTE J1650-500 DOM WALTON IoA, Cambridge, UK In collaboration with Rubens Reis, Ed Cackett, Jon Miller and Andy Fabian Berlin: 2011

  2. BLACK HOLE ACCRETION f f   Dom Walton Berlin: 2011

  3. AGN SPECTRA 1H 0707-495 - Zoghbi et al. (2010) (see also Fabian et al. 2004, Boller et al. 2002, etc.) Dom Walton Berlin: 2011

  4. BLACK HOLE ACCRETION f f  Dom Walton Berlin: 2011

  5. DISC REFLECTION f f  Dom Walton Berlin: 2011

  6. RELATIVISTIC EFFECTS Characterising the reflection component is one way in which we can measure BH spin Fabian et al. (2000) Dom Walton Berlin: 2011

  7. BLACK HOLE BINARIES • Spectra obtained from Galactic black hole binaries (BHBs) show the same primary continuum components as AGN: • Many also display broad excesses at ~6 keV • BHBs are brighter due to their proximity, so any absorption features can be well constrained • Thermal emission (accretion disc, low energy) • Comptonised emission (corona, high energy) Dom Walton Berlin: 2011

  8. XTE J1650-500 • 2001 outburst observed by XMM (burst mode, x1) and BeppoSAX (x3) • Displays a broad excess at ~6 keV, independent of Comptonised continuum model: • Gaussian: σ = 1.2 ± 0.2 keV • Laor: Rin = 1.5 ± 0.1 RG Dom Walton Berlin: 2011

  9. XTE J1650-500 • 2001 outburst observed by XMM (burst mode, x1) and BeppoSAX (x3) • Displays a broad excess at ~6 keV, independent of Comptonised continuum model: • Note residual instrumental features at ~1.8 and 2.2 keV • Gaussian: σ = 1.2 ± 0.2 keV • Laor: Rin = 1.5 ± 0.1 RG Dom Walton Berlin: 2011

  10. DISC REFLECTION MODEL - Powerlaw - Relativistic disc reflection (incl. thermal continuum) REFBHB (Ross & Fabian, 2007); Rin ~ 2 RG Dom Walton Berlin: 2011

  11. SOFT RESIDUALS • Soft residuals at ~0.8 keV persist. Possible astrophysical origins: • Comparison with burst mode Crab data shows similar residuals, so likely to be systematic • Doesn't effect inner radius obtained (always ~2 RG) • Additional reflected OVIII emission and/or Neon absorption in the ISM • Local ionised absorption (disc wind) Dom Walton Berlin: 2011

  12. INSTRUMENTAL EFFECTS There are claims the line profiles obtained could be broadened and skewed by instrumental effects, e.g. pile-up, charge transfer inefficiency. Comparison with contemporaneous BeppoSAX MECS data (obtained ~1 day prior to XMM observation): • The line profile is independent of detector type (MECS detectors are gas based) • Profile is not significantly modified by instrumental effects Dom Walton Berlin: 2011

  13. COMPTON BROADENING • Compton broadening in the disc is self-consistently included in REFBHB • 'Windline' models run into problems with the mass outflow rates required • Electron temperature (~6 keV) and optical depth (~1) required to broaden the line in the corona are not consistent with those found for the continuum • Also expect the line centroid energy to increase by ~0.35 keV, but EG < 6.5 keV Dom Walton Berlin: 2011

  14. LINE PROFILE EVOLUTION • Latter two BeppoSAX observations were obtained later in the evolution of the outburst • Line profiles obtained do not show significant deviations from early BeppoSAX and XMM observations • This is not consistent with the expected behaviour for scenarios dominated by electron scattering Dom Walton Berlin: 2011

  15. XTE J1650-500 SPIN 0.84 ≤ a* ≤ 0.98 (90% confidence) Dom Walton Berlin: 2011

  16. MCG -6-30-15 • Seyfert 1.2 AGN, 350 ks XMM observation taken in 2001 • Spectrum complicated by a warm absorber, accounted for by the model of Chiang & Fabian (2011) • Also displays a broad excess at ~6 keV Absorption model includes: • Fast, highly ionised component • 2 slow, lower ionisation components • Iron-L dust absorption Dom Walton Berlin: 2011

  17. LINE PROFILES Dom Walton Berlin: 2011

  18. LINE PROFILES Dom Walton Berlin: 2011

  19. COMMON ORIGIN • As the excesses at ~6 keV broad iron lines observed in AGN and BHBs are similar, we would like to find a common physical origin for them. • Absorption does not (usually) significantly modify the spectra of BHBs • Reflection from the inner accretion disc is the only viable common interpretation Dom Walton Berlin: 2011

  20. SUMMARY • The BHB XTE J1650-500 displays a broad iron line profile (see also earlier works by Miller+ 2002, 2009, Miniutti+ 2005) • The line profile requires that the emission arises in the regions of strong gravity close to the black hole, and is similar to those seen in AGN • As BHBs provide an unobscured view of the accretion flow, relativistic disc reflection must be a fundamental process in the disc-corona geometry • Comparison with BHBs therefore provides a strong argument in favour of the presence of relativistic disc reflection in AGN Dom Walton Berlin: 2011

  21. EPFAST • EPFAST attempts to correct for the features at ~2 keV; applies an energy independent correction • CTI is energy dependent (CTI ~ E-0.5); EPFAST over-corrects at iron K energies EPFAST Dom Walton Berlin: 2011

More Related