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)

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

BELR = Disk+Wind? 2-component BELR as in Collin et al. 2006, shielding gas as in Murray et al. 2000, Gallagher et al BELR 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.

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

Disk+Wind Leighly 2004

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

Winds from Emission We use 2 key emission line diagnostics from C IV 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.

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

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

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

EV1 Sulentic et al 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.

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

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

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

SEDs vs. M, Mdot Boroson 2002 K. Leighly

Bolometric Correction Biases 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. But these have different SEDs and thus (systematically) different bolometric corrections.

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.

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

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

Mass Biases II BELR 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.

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 BAL M Time/Spin?

Conclusions Strong evidence for a 2-component BELR (a disk and a wind). 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. 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. “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. It is important to explore potential biases in estimates of mass and accretion rate across this parameter space.

An Aside: Bolometric Corrections Want Bolometric Luminosity Monochromatic Have Monochromatic Luminosity K is always assumed to be a constant that is the same for all quasars.

Bolometric Correction Biases Krawczyk et al. (in prep.) We always assume a constant bolometric correction. However, these will have very different corrections. That is the same thing as saying these objects with different wind properties will have different bolometric corrections.

Mass and Luminosity Steinhardt & Elvis 2010

Mass Biases III It is actually worse than that. It turns out that the dynamic range in luminosity is much larger than the dynamic range in FWHM. So, our mass estimates are really just Croom et al. 2011

Accretion Rate Biases Our usual estimate of the (mass-weghted) accretion rate is the Eddington ratio. L_bol/M = M_dot/M But this suffers from both the mass and bolometric correction biases.

Conclusions II Quasars may act as the control valve for the growth of galaxies. Quasars may act as the control valve for the growth of galaxies. Winds from the accretion disk are one of the possible sources of feedback Winds from the accretion disk are one of the possible sources of feedback Incomplete understanding of the range of wind properties may be biasing our view of quasar masses and accretion rates (and thus our understanding of the role that quasars play in galaxy evolution). Incomplete understanding of the range of wind properties may be biasing our view of quasar masses and accretion rates (and thus our understanding of the role that quasars play in galaxy evolution). Color BELR

GALEX and the Ionizing SED Krawczyk et al. (in prep.) Spitzer 2MASS SDSS GALEX

Mass and Accretion Rate Need to relate the properties of disk winds to intrinsic physical properties like mass and accretion rate. Masses can be estimated from scaling relations (e.g. Vestergaard and Peterson ’06) The Accretion Rate is related to the Bolometric Luminosity. Assuming a mean SED incurs errors in accretion rate estimates.

SED/Shielding Dependence v term ~ (GM BH /R launch ) 1/2 (cf. Chelouche & Netzer 2000; Everett 2005) smaller R launch  higher v term thicker shield  more X-ray weakthinner shield  less X-ray weak larger R launch  lower v term (Gallagher et al. 2006; Gallagher & Everett 2007)

2-Component BELR 1.The Disk Dominated by Low-ionization lines Single-peaked due to large distance? 2.The Wind Dominated by High-ionization lines Single-peaked due to radiative transfer effect (Murray & Chiang)

How Disk Winds Work Elvis 2004 UV photons drive a wind due to radiation pressure on resonant spectral lines.

SED/Shielding Dependence v term ~ (GM BH /R launch ) 1/2 (cf. Chelouche & Netzer 2000; Everett 2005) smaller R launch  higher v term thicker shield  more X-ray weak thinner shield  less X-ray weak larger R launch  lower v term (Gallagher et al. 2006; Gallagher & Everett 2007)

The View Through the Wind UV X-ray shielding gas BAL wind Broad Absorption Line (BAL) Quasars Proga & Kallman (2004)

Emission Line Diagnostics Baldwin 1977; Richards et al & in prop. Luminosity Line Strength Richards et al. 2002, 2006 & in prep. Wavelength Flux

Dusty region

Different views through the wind UVX-rayIR Adapted from S. Gallagher

Both MHD+LD Winds? Elvis 2000 NAL region BAL region Black Hole/X-ray Continuum Accretion Disk MHD Dominated  Line Driven Dominated Richards et al. 2004/2006/2009

Eddington Luminosity/Mass If the luminosity of a quasar is high enough, then radiation pressure from electron scattering will prevent further gravitational infall. L E = 1.38x10 38 M/M sun erg/s M E = 8x10 7 L 46 M sun Sets an upper limit to the luminosity for a given mass, or alternatively a minimum mass for a given luminosity.

Modeling Disk Winds Proga & Kallman 2004

Accretion Disk Radiation (Gallagher et al. 2002a: Adapted from Königl & Kartje 1994; Murray et al. 1995) Black Hole Strong X-rays (~ light hours) Weak X-rays UV Light Optical Light (~ light years)

Accretion Disk Wind Wind (Gallagher et al. 2002a: Adapted from Königl & Kartje 1994; Murray et al. 1995) UV light from the accretion disk pushes on electrons in the “atmosphere” of the accretion disk and drives a wind. This wind deposits energy into the system. Proga et al. 2000

UV quasar spectra v outflow ~ ( )c Broad Absorption Lines (P Cygni profiles) Ly  /NV SiIV CIV S. Gallagher

Urry & Padovani 1995 Black Hole Accretion Disk Broad Line “Clouds” Narrow Line “Clouds” Radio Jet Dusty Torus

An Aside: Virial Masses