1. The nature of X-ray selected Broad Absorption Line Quasars Alex Blustin With Tom Dwelly (Southampton), Mat Page (UCL-MSSL)‏ UCL-MSSL and IoA, Cambridge X-ray Universe 2008, Granada, Spain

2. What are Broad Absorption Line Quasars (BALQSOs)? Quasars with very broad restframe UV absorption features from the wind: z ~ 0.1 – 6 wind outflow speed up to 60,000 km/s N H ~ 10 24 cm -2 Rarely detectable in X-rays due (probably) to high absorption from the ionised wind

3. Why have we started to find BALQSOs in X-ray surveys? Optically-selected (OBALQSOs): discovered in optical surveys X-ray selected (XBALQSOs): discovered in X-ray surveys

4. Why have we started to find BALQSOs in X-ray surveys? Optically-selected (OBALQSOs): discovered in optical surveys X-ray selected (XBALQSOs): discovered in X-ray surveys Are they easier to detect in the X-rays due to low absorption from the wind? Are they exceptionally luminous BALQSOs with high dust extinction (hence faint in optical but bright in X-rays)? Do they have intrinsically higher X-ray to optical flux ratios?

5. XBALQSOs in two deep XMM-Newton X-ray survey fields 1 H field CDFS ~400 ks XMM EPIC z = 2.63 z = 1.793 z = 1.40 z = 2.64 z = 2.82 ~100 ks XMM EPIC Keck-LRIS WHT-AF2 WYFFOS VLT-FORS Szokoly et al. 2004

6. XBALQSOs in two deep XMM-Newton X-ray survey fields 1 H field CDFS ~400 ks XMM EPIC C IV 1549 Å absorption from wind z = 2.63 z = 1.793 z = 1.40 z = 2.64 z = 2.82 ~100 ks XMM EPIC Keck-LRIS WHT-AF2 WYFFOS VLT-FORS Szokoly et al. 2004

7. Fitting the X-ray absorption due to the wind Same velocity structure as in UV Standard Spectral Energy Distribution (SED)/continuum for absorber model generation and spectral fitting Same ionisation parameter  and column N H for all velocity components Few X-ray counts in spectra We need to make some assumptions:

8. Velocity structure of the (rest-frame) UV-absorbing wind V out = 670, 2170 km/sFWHM = 1140, 2610 km/s V out = 1680 km/s FWHM = 2430 km/s V out = 4100, 1330 km/s FWHM = 2390, 1460 km/s V out = 12740, 18750 km/s FWHM = 3790, 5210 km/s V out = 1900, 4220 km/sFWHM = 1940, 3220 km/s

9. Spectral Energy Distributions Based on Marconi et al. 2004Read-out from refl reflection model in SPEX 2.00.11 X-ray to optical slope set using  ox calculated from 2500 Å flux (Vignali, Brandt & Schneider 2003)‏

10. X-ray fits Three free parameters: continuum normalisation absorbing column N H ionisation parameter  Spectra from XMM-Newton EPIC (combined)‏

11. Is there less X-ray absorption from the wind in XBALQSOs? PG1115+080 (Chartas et al. 2007)‏ Q1246-057 (Grupe et al. 2003)‏ SBS1542+541 (Grupe et al 2003)‏ PG2112+059 (Gallagher et al. 2004)‏ OBALQSOs

12. Is there less X-ray absorption from the wind in XBALQSOs? If so, XBALQSOs here OBALQSOs PG1115+080 (Chartas et al. 2007)‏ Q1246-057 (Grupe et al. 2003)‏ SBS1542+541 (Grupe et al 2003)‏ PG2112+059 (Gallagher et al. 2004)‏

13. Is there less X-ray absorption from the wind in XBALQSOs? If so, XBALQSOs here OBALQSOs XBALQSOs

14. Is there less X-ray absorption from the wind in XBALQSOs? Probably not OBALQSOs XBALQSOs Nearby AGN (Blustin et al. 2005)

15. How does the UV absorption by the wind compare? Consistent with amount of UV line absorption in SDSS OBALQSOs SDSS OBALQSOs from Trump et al. 2006

16. Are XBALQSOs just highly luminous BALQSOs with extra dust extinction? OBALQSOs (Gallagher et al. 2006)‏ XBALQSOs No, consistent with OBALQSOs Expected B-Ks for SDSS QSOs Vanden Berk et al. 2001

17. X-ray flux, optical flux and  ox Log 2 keV flux Log 2500 Å flux  ox OBALQSOs: median  ox = -2.20 (stdev 0.21)‏ XBALQSOs: median  ox = -1.90 (stdev 0.13)‏ Given the median UV fluxes of the samples, the Vignali, Brandt & Schneider (2003) relation predicts a 0.13 difference in  ox ; we observe a difference of 0.30. OBALQSOs (Gallagher et al. 2006)‏ XBALQSOs

18. X-ray flux, optical flux and  ox Log 2 keV flux Log 2500 Å flux  ox OBALQSOs: median  ox = -2.20 (stdev 0.21)‏ XBALQSOs: median  ox = -1.90 (stdev 0.13)‏ Given the median UV fluxes of the samples, the Vignali, Brandt & Schneider (2003) relation predicts a 0.13 difference in  ox ; we observe a difference of 0.30. The XBALQSOs may have an intrinsically higher X-ray to optical flux ratio than the OBALQSOs OBALQSOs (Gallagher et al. 2006)‏ XBALQSOs

19. Conclusion: These XBALQSOs are probably not fundamentally different from the broader BALQSO population. However - they are relatively X-ray rich. Deep (hard) X-ray surveys are now sensitive to this part of the AGN population... As (hard) X-ray surveys get deeper, we can expect to detect a lot more BALQSOs like these in X-rays.