Black Hole - Bulge Relation of High Redshift Quasars Xue-Bing Wu (Dept. of Astronomy, Peking University)

Outline n Black Hole Mass Determinations n Black Hole - Bulge Relation n High-z Quasars n Comparison with PG Quasars n Discussions

1. Black Hole Mass Determinations Supermassive Black Holes in the Center of Nearby Galaxies (Kormendy & Gebhardt 2001; Ho 1999) Stellar dynamics Mass determined by the rotational velocity V and the velocity dispersion  of stars Gas dynamics Keplerian rotation of ionized gas in a disk-like configuration Water maser dynamics 22 GHz microwave emission from extragalactic water masers

Stellar Dynamics Our Galaxy (Genzel et al. 1997,2003; Ghez et al. 1998, 2005) M * =(3~4) E6 Msun Stellar velocity & proper motions around Sgr A* yield a BH mass of (3~4) 10 6 Msun

Estimate the BH mass of AGNs: a difficult task Direct dynamical methods Stellar dynamical studies not feasible in AGN, since the AGN is so bright to outshine the stars. Can use gas and megamaser dynamics only for several nearby AGNs (M87, NGC4258,…) Indirect methods Fitting the observed ‘big blue bump’ in the UV/optical spectra depends on other parameters: accretion rate, disk inclination,... Fitting the iron K  line in the X-ray spectra depends on other parameters: emissivity law, inclination, BH spin,...

–Broad line region (BLR): pc; emission lines are produced by the illumination of the AGN's photoionizing continuum radiation –BLR size can be estimated by the time delay that corresponds to the light travel time between the continuum source and the line- emitting gas: R BLR =c  t –BLR characteristic velocity V can be estimated by the width (FWHM) of broad emission line Reverberation mapping from optical/UV variability Peterson (1997)

BLR Scaling with Luminosity A simple photoionization model predicts: Consistent with the reverberation mapping results r  L 1/2 With the R-L relation, from the optical continuum luminosity we can estimate the BLR size and then BH mass of AGNs r  L 0.6±0.1

SMBH in the highest redshift quasar SDSS J (z=6.42) Willott et al. (2003) (UKIRT/UIST) FWHM(MgII)=6000km/s  M BH =3E9 Msun Barth et al. (2003) (Keck II/NIRSPEC) FWHM(MgII)=5500km/s  M BH =2E9 Msun FWHM(CIV)=9000km/s  M BH =6E9 Msun

2. Black Hole - Bulge Relation n Black hole mass / bulge mass ~ (0.002) (Maggorian et al. 1998, AJ, 115, 2285 ) n Is the ratio constant? Is it different for different types of galaxies (Wandel 2002; Laor 2001; Wu & Han 2001; Wu, Liu & Zhang 2002) M BH  M bulge 1.74

Black Hole - Bulge Relation n Black hole mass - bulge stellar velocity relation (M -  relation) (Gebhardt et al. 2000; Merritt & Ferrarese 2000; Tremaine et al. 2002) M BH  4 Tremaine et al. (2002) Kormendy & Gebhardt (2002)

Black Hole - Bulge Relation n Two of the first works using the M -  relation to estimate AGN BH mass (Wu & Han 2001, A&A, 380, 31; Wu & Han 2001, ApJ, 561, L59) n “ Abstract: We estimated black hole masses for 9 Seyfert 1 and 13 Seyfert 2 galaxies in the Palomar and CfA bright Seyfert samples using the tight correlation between black hole mass and bulge velocity dispersion…” (Woo & Urry 2002, ApJ)

Black Hole - Bulge Relation n Origins of the black hole -bulge relation –Physics tie between BH and galaxy formation –Feedback scenario (Silk & Rees 1998; King 2003, 2005;…) –Two-direction starburst feedback model: Xu, Wu & Zhao (2007 ApJ); Xu & Wu (2007 ApJ)

The obscured growth of central BH at the early growth stage (Xu, Wu & Zhao 2007, ApJ) The outward starburst feedback resists the gravity of dark matter halo while the inward one regulates the growth of the BH. Because the mass of BH is small at early stage, the feedback from BH can’t balance the inward feedback from the starburst. The BH will hide in the thick gas shell and can not be seen in optical band.

BH - bulge relation of AGNs Ferrarese et al. (2001) Onken et al. (2004)

M -  relation of quasars For quasars: direct measurement of  is difficult;  =FWHM([OIII])/2.35 is usually adopted (Nelson 2000; Shields et al. 2003); galaxy growth is contemporaneous with black hole growth up to z=2~3

M -  relation of SDSS DR3 quasars ( sources, z<1.2) Salviander et al. (2007, ApJ) Evolution at hi-z?

Coppin et al. 2008, MNRAS

3. High-z Quasars n How about M -  relation at Hi-z? n Black hole mass of hi-z quasars can be estimated using the R-L relation (3E9 solar mass for the BH of a quasar at z=6.4)(Willott et al. 2003; Barth et al. 2003) n Different R-L relations (Kaspi et al. 2000,2005; Vestergaard et al. 2002; McLure & Dunlop 2002; Wu et al. 2004, A&A) n How to estimate  at hi-z? –Direct measurement? No –Using narrow line such as [OIII]? No

High-z Quasars n CO molecular emissions have been detected in a number of hi-z quasars, including SDSS J (z=6.42) Walter et al. (2004, ApJL)

High-z Quasars n CO molecular line detected for a number of hi-z quasars (Solomon & Vanden Bout 2005 ARA&A) n CO line width as a surrogate for  (Shields et al ApJ, 641, 683) n  =FWHM(CO)/2.35 Hi-z quasars, outliers?? (Shields et al. 2006)

High-z Quasars n Can we use  =FWHM(CO)/2.35 ?? n A test with CO detected 33 Seyfert galaxies (Wu 2007, ApJ, 657, 177) n A better correlation using inclination-corrected line width n CO molecular disk coplanar with the galaxy disk (Heckman et al. 1989) Wu (2007, ApJ)

High-z Quasars n Assuming inclination ~15 o of hi-z quasars, we can re-estimate  values using the inclination-corrected CO line width and study the M -  relation at Hi-z Wu (2007, ApJ)

High-z Quasars n Small inclinations (~15 o ) are also probably needed to explain the narrowness of CO line of hi-z quasars compared with the sub-millimeter galaxies (SMG) (Greve et al. 2005; Carilli & Wang 2006) Carilli & Wang (2006,AJ)

Recent simulations on the morphology and line profile of hi-z quasars (Narayanan et al. 2007)

4. Comparison with PG Quasars n Most PG quasars seem to follow the M -  relation (Shields et al. 2006) n Are two narrow CO PG quasars the outliers? n PG (FWHM =60km/s) and PG (FWHM=90 km/s) (Evans et al. 2006) (Shields et al. 2006)

Two Narrow CO PG Quasars n PG (FWHM(CO)=90km/s) n  =115  12 km/s (Kauffman et al. 2003, MNRAS) n Clearly,  =FWHM(CO)/2.35 n If n i=15 o

Two Narrow CO PG Quasars n Narrow CO PG quasars are almost face-on (<20 o ) n  =FWHM(CO)/2.35 can not apply n They are not outliers of the M -  relation (If the proper  values can be obtained)

PG quasars with measured  n Dasyra et al. (2006, ApJ) Long integration H- band spectroscopy with VLT

PG quasars with measured  n M -  relation of PG quasars Dasyra et al. (2006, ApJ)

5. Discussions n Black hole - bulge relation for quasars seems to be consistent with the local one n Accurate measurements of BH mass and stellar velocity dispersion for a large sample of quasars at different redshift are needed n Hi-z quasars ( evolution of the BH – bulge relation?); mm and cm study n Theoretical understandings of the origin (and evolution) of the BH – Bulge relation