CIV Emission as a Probe of Accretion Disk Winds

1. CIV Emission as a Probe of Accretion Disk Winds Gordon Richards Drexel University With thanks to Sarah Gallagher (UWO), Karen Leighly (OU), Paul Hewett (IoA, Cambridge), and Nick Kruczek, Rachael Kratzer, and Coleman Krawczyk (Drexel)

2. Clouds (and Torus?) => Disk Winds Elvis 2000 Urry & Padovani 1995 Proga 2005 (see also Everett 2005)

3. BELR = Disk+Wind? BELR BELR 2-component BELR as in Collin et al. 2006, shielding gas as in Murray et al. 2000, Gallagher et al. 2006 We consider a model where the Broad Emission Line Region comes from both the disk and the wind (e.g., Leighly 2004, Collin et al. 2006). If the wind is stronger, the disk component is more shielded from ionizing photons (and thus is weaker) and vice versa.

4. Filtered Continuum In the model of Leighly 2004, the disk isn’t just a separate component, it sees a different continuum than the wind (and possibly different from what we see [e.g. Korista 1997]). Leighly 2004; Leighly & Casebeer 2007

5. Disk+Wind Leighly 2004

6. A Range of Intrinsic SEDs While the disk may see a different filtered continuum for different strength winds, the structure of the wind depends on the intrinsic SED. Not BALs BALs Leighly et al. 2007

7. Winds from Emission We use 2 key emission line diagnostics from CIV in the redshift range where BALs are found to learn more about winds. Specifically, we can place objects along a continuum of BELR properties ranging from “disk”- to “wind”-dominated. This helps to identify the parent sample of objects from which BALQSOs are drawn. These parameters may also describe unbiased tracers of mass and accretion rate.

8. The Baldwin Effect More luminous quasars have weaker CIV lines (Baldwin 1977). Seen here from an SDSS sample with 30k quasars. Dietrich et al. 2002 explores many other lines. Richards et al. 2011

9. CIV “Blueshifts” The peak of CIV emission is generally not at the expected laboratory wavelength (e.g., Gaskel 1982). Richards et al. 2011, with redshifts from Hewett & Wild 2010

10. CIV Parameter Space Can form a joint parameter space with these two observations. Generally speaking radio-loud quasars and BALQSOs live in opposite corners. Radio-Loud BALQSOs Richards et al. 2011

11. EV1 At low-z EV1 parameters show a similar distribution. Sulentic calls these Pop A/B, but it may be possible to use a more physically motivated terminology. Sulentic et al. 2000

12. SED Extrema These objects have (hard) SEDs like this. These objects have (soft) SEDs like this. Kruczek et al. 2011

13. CIV Parameter Space Ionizing SED, Weak LD winds 0% Radio-Loud Less ionizing SED, Strong LD winds SEDs affect winds, which affect BAL covering fractions. BALQSOs 40% Richards et al. 2011

14. More ionizing flux = strong disk component High radio-loud prob; low BALQSO prob Less ionizing flux = strong wind component Low radio-loud prob; high BALQSO prob

15. SEDs vs. M, Mdot K. Leighly Boroson 2002

16. Bolometric Correction Biases But these have different SEDs and thus (systematically) different bolometric corrections. Accretion rates (and Eddington Ratios) are estimated from the Bolometric Luminosity. The Bolometric Luminosity, in turn, is estimated from a Monochromatic Luminosity and a universal bolometric correction based on a universal SED.

17. Bolometric Correction Biases II The situation may be even worse than you think as this plot from before simply extrapolated between the UV and X-ray. However, there has long been evidence that the (unseen) EUV part of the SED might look different (e.g., Korista et al. 1997) In fact, I’d argue that the “hard”-spectrum SEDs may look something more like this.

18. Mass Biases I All reverberation-mapped AGNs live here. Scaling relations derived from these objects may not apply here.

19. CIV vs. Others • Obviously CIV, but what about MgII or Hbeta? • Wang et al. 2011: MgII is consistent with being from the disk and CIV from both. • Steinhardt and Silverman 2011 results further support this and may argue for Hbeta also being from both.

20. Mass Biases II The wind may influence even disk measurements if it biases the R-L relationship. Same Ls may have different Rs if the continuum reaching the disk is filtered differently. BELR BELR

21. M-L: The Bottom Line Mean mass and accretion rates may be fine, but it could be dangerous to make comparisons between extrema. Eddington Ratio can be a dangerous parameter as high M, high Mdot != low M, low Mdot. RL Time/Spin? M BAL

22. Conclusions • Strong evidence for a 2-component BELR (a disk and a wind). • CIV (and other) emission provides a way for determining the relative strengths of these components. • “Hard” SEDs have weak winds and “Soft” SEDs have strong winds. • It is important to explore potential biases in estimates of mass and accretion rate across this parameter space.