Supermassive Black Holes in Supermassive Black Holes in Radio-loud AGNsRadio-loud AGNs

Xue-Bing WU (Peking Univ.) Xue-Bing WU (Peking Univ.)

Collaborators:

PKU: FuKun Liu, Ran Wang

NAOC: JinLin Han, MinZhi Kong

• Supermassive black holes in nearby galaxies (mass determined by stellar, gas, & water maser dynamics)(Kormendy & Richstone 1995; Kormendy & Gebhardt 2001; Ho 1999)• Supermassive black hole formation is closely related to galaxy formation

1. Introduction

Tremaine et al.

(2002)

MBH 4

AGN Structure

•Supermassive black hole •Accretion disk•Broad line region•Dusty torus•Narrow line region•Jet

Black hole mass estimations of AGNs

Direct methods•Stellar dynamics: not feasible, since the AGN is too bright.

•Gas kinematics: only in a few cases, if the gas is seen in Keplerian rotation. In M87, r=75 pc disk yields 3 109 Msun

•Megamasers: only in several edge-on Sy2s. In NGC4258, 0.02 pc resolution gives perfect Keplerian rotation. 3.6 107 Msun

Indirect Methods• Accretion disk fitting of the big blue bump in th

e UV/optical spectra of AGN– Standard thin disk model (Shakura & Sunyaev 1973):

)( 1

RdRcos4 11R

R )(/22

3out

in

Hzergs

eDc

ihF

RkTh

Broad gravitational-redshifted Iron K line of Seyfert 1 galaxies--accretion disk modeling

Tanaka et al. (1995); Nandra et al. (1997)

Fabian et al. (1989)

– Broad emission line region: 0.01 - 1pc; The AGN's photoionizing continuum radiation is reprocessed into emission lines

– RBLR estimated by the time delay that corresponds to the light travel time between the continuum source and the line-emitting gas: RBLR =c t

– V estimated by the FWHM of broad emission line

G

RVM BLR

2

*

FWHM(H ), 3 / 2 for random distribution of BLR cloudsV f f

Reverberation mapping from optical variability

Peterson (1997)MrK 335: t=15.6 days

BLR Scaling with LuminosityBLR Scaling with Luminosity

2HH

24

)H(

rn

L

cnr

QU

r L0.6±0.1

• Photoionization model prediction

Same ionization

parameter Same density

r L1/2

With the empirical R-L relation, we can estimate the BLR size from the optical continuum luminosity

Kaspi et al. (2000)

SMBH and Galactic Bulge

• Relations of black hole mass with bulge luminosity and central velocity dispersion (for both normal galaxies & AGNs)

Ferrarese et al. (2001)

AGN

With the MBH -σ relation, we can estimate the BH mass of AGNs from the measured stellar velocity dispersion

2. AGN BH Mass estimation with the R-LH relation

(Wu, Wang, Kong, Liu & Han 2004, A&A, 424, 793)• BLR sizes are usually derived previously from the empirical relation R L5100A

0.7(Kaspi et al. 2000). Can it apply to RL AGN?

• Optical jets of some AGNs have been observed by the HST (Scarpa et al. 1999; Jester 2003; Parma et al. 2003). Optical Synchrotron radiations have been found in some RL AGNs (Whiting et al. 2001; Chiaberge et al. 2002; Cheung et al. 2003)

For radio-loud AGNs, optical continuum luminosity may be significantly contributed from jets, thus may not be a good indicator of ionizing luminosity

It may be better to use the relation between the emission line luminosity and the BLR size

3C 273

• An empirical relation between the BLR size and emission line luminosity (Spearman’s rank r=0.91)

• Comparison of the results obtained with two R-L relations : Using the R-L5100A relation may overestimate MBH for radio-loud quasars!

Recently we also extended such a study to UV broad emission lines (Kong, Wu, Wang, & Han 2005, A&A )

3. 3. SMBH Mass of AGNs with elliptical host SMBH Mass of AGNs with elliptical host (Wu, Liu & Zhang, 2002, A&A, 389, 742)(Wu, Liu & Zhang, 2002, A&A, 389, 742)

Reverberation mapping can not apply to BL Lacs, a subclasReverberation mapping can not apply to BL Lacs, a subclass of radio-loud AGNs without/with weak emission liness of radio-loud AGNs without/with weak emission lines

Only a dozen of BL Lacs have measured Only a dozen of BL Lacs have measured values and the es values and the estimated SMBH masses: 5E7 to 1E9 solar masses (Falomo et timated SMBH masses: 5E7 to 1E9 solar masses (Falomo et al. 2002; Barth et al. 2002)al. 2002; Barth et al. 2002)

Host galaxies of BL Lacs are ellipticals (Urry et al. 2000)Host galaxies of BL Lacs are ellipticals (Urry et al. 2000) values can be derived based on the values can be derived based on the fundamental planefundamental plane of e of e

llipticals; then SMBH masses could be estimated for BL Lacllipticals; then SMBH masses could be estimated for BL Lacs with high-quality imagess with high-quality images

Fundamental plane of elliptical galaxies

(Bettoni et al. 2001)

(Djorgovski & Davis 1987; Dressler et al. 1987; Faber et al. 1989;

Jorgensen et al. 1996)

SMBH Masses of AGNs with E hostSMBH Masses of AGNs with E host Sample 1Sample 1: : 63 BL Lacs (51 HBLs; 63 BL Lacs (51 HBLs;

12 LBLs) with known redshift fro12 LBLs) with known redshift from HST snapshot survey (Urry et am HST snapshot survey (Urry et al. 2001). No significant difference il. 2001). No significant difference in SMBH masses between HBLs & n SMBH masses between HBLs & LBLsLBLs

Sample 2Sample 2: HST imaging sample o: HST imaging sample of 10 RGs, 10 RLQs & 9 RQQs with f 10 RGs, 10 RLQs & 9 RQQs with elliptical hosts (McLure et al. 1999;elliptical hosts (McLure et al. 1999; Dunlop et al. 2002). SMBH masse Dunlop et al. 2002). SMBH masses of RQQs are slightly less than ths of RQQs are slightly less than those of RLQs; different from previoose of RLQs; different from previous claimsus claims

Comparison of Eddington ratios of AGNsComparison of Eddington ratios of AGNs

The Eddington ratios (dimensionless accretion rates) of radio galaxies are about two orders lower than those of quasars.

Radio galaxy

Quasars

4. Discussion & Summary

• Knowing the BH mass is important and helpful to other AGN studies

SD: Slim disk (Abramowicz et al. 1988)

RTD, GTD: Radiation pressure and gas pressure dominated thin disk (Shakura-Sunyaev 1973)

SLE: Hot, two-temperature disk (Shapiro, Lightman & Eardley 1976)

ADAF: Advection dominated accretion flow (Narayan & Yi 1994)

Abramowicz et al. (1995)

•Accretion disk structure is strongly dependent on the accretion rate

“A fundamental plane of black hole activity”

(Merloni et al. MNRAS, 2003)

SMBH in highest redshift quasar (z=6.4)

Willott et al. (2003) (UKIRT/UIST)

FWHM(MgII)=6000km/s MBH=3E9 Msun

Barth et al. (2003) (Keck II/NIRSPEC)

FWHM(MgII)=5500km/s MBH=2E9 Msun

FWHM(CIV)=9000km/s MBH=6E9 Msun

Supermassive black hole formed in the early universe!

Summary

• Supermassive black holes with mass of 106 to 109 solar masses exist in the center of both normal and active galaxies

• Dynamic methods of estimating the BH mass can only be applied to several nearby AGNs. Reliable BH mass of AGNs (including RL AGNs) can be obtained by reverberation mapping, MMBHBH - - relation and two empirical R-L relations

• BH mass study is important and helpful to other AGN studies (accretion rate; BH spin; jet…)