Black Hole Growth in the Local

Universe

Jenny E. Greene (Hubble/Princeton-Carnegie Fellow)Luis C. Ho (Carnegie), Aaron J. Barth (UC Irvine)

Marconi et al. 2004

Galaxy luminosity function→BH mass function Primary mode of BH growth AGN lifetimes, radiative efficiency

Local BH Mass Functions

BHs Growing TodayHeckman et al. 2004

All BHs (active+inactive)

Narrow-line AGNsDistribution of L[OIII]

Broad-line AGNs- masses from AGN physics- compare broad and narrow line AGNs- sensitive to low-mass (<106 M⦿) BHs

Only means to probe this regime is using AGNs, since current resolution inadequate

for dynamical detection

Haehnelt 2004

But isn’t this a neglible fraction of total BH mass and radiated lumiminosity?

Disproportionate Import

LISA

Primordial Seeds

Bromm & Loeb

GC

dSph

dE

E

Merritt et al. 2004

Gravitational Recoil

Gravitational radiation

Stellar Mass

Low-mass BHs are rare?

Groves et al. astroph/0607311

All galaxies

Active galaxies (narrow-line)

Greene & Ho 2004 found only 19 broad-lineAGNs in DR1 (<106 M⦿)

The Search• z<0.35 broad-line AGNs from SDSS

•Galaxy Survey: r < 17.77; extended (e.g. Hao et al. 2005, Heckman et al. 2004)

•AGN Survey: 15 < i < 19.1; color-selected

PCA (Hao et al. 2005)

[S II] λλ6716, 6731

Hα + [N II] λλ6548, 6583

Modeling (Greene & Ho 2004)

~8000 AGNs, 2000 from main galaxy sample

LHα FWHMHα

Standard scaling relations (BLR radius and AGN

luminosity)

Greene & Ho 2005

MBH Lbol/LEdd

Greene & Ho in prep

Lbol/LEdd

0.01

0.030.10.3

1

Greene & Ho in prep

SDSS bright limit

Hα Luminosity Function

broad Hα luminosity function 8300 broad-line AGNs

Vmax method

Contaminants

Ho 2004

Greene & Ho in prep

BH Mass FunctionsGreene & Ho in prep

Text

?

“ Cosmic Downsizing”

MBH*

All T2s from SDSS

Greene & Ho in prep

Seyfert T2s

Broad-line AGNs

CF with Heckman et al. 2004

CF with Hasinger et al 2005

Soft X-ray LFInferred from optical

using αox

Monte CarloReal turnover at the low-mass end

ORlow-mass BHs are quiescent ORincorrect galaxy luminosities

z=0.05 z < 0.02 z =0.1

0.0

1 <

L/

L Edd<

0.1

0.1

<

L/L E

dd<

0.3

0.3

<

L/L E

dd<

3

log (MBH/M⦿)5 6 7 8 9 5 6 7 8 95 6 7 8 9

GH02 GH08 GH05

GH17 GH04 GH09

19 AGNs (<106 M⦿) Greene & Ho 2004HST/ACS: F435W (B), F814W (I), 1 orbit/source

Greene, Barth, & Ho in prep7 kpc

3 kpc

8 kpc

7 kpc

10 kpc

4 kpc

20 kpc

MBH-L

Bul

ge

Mar

coni

& H

unt

(200

3)

Greene & Ho 2004

NGC 4395

Pox 52

5 mag

GALFITPeng et al. 2002

Greene, Barth, & Ho in prep

PSF + 1 Sersic fit

Barth et al. 2004

Filippenko & Ho 2003

Barth, Greene, & Ho 2005

Lauer et al. 2006/astroph0606739Ferrarese et al. 2006

Star-cluster mass correlated with galaxy mass (see also Wehner & Harris 2006, Rossa et al. 2006)

Conclusions(preliminary)

• We construct BH mass functions using 9000 local broad-line AGNs from SDSS

• We investigate, for the first time, the space density of the lowest-mass AGNs known (<106 M⦿)

• Preliminary evidence that low-mass BHs are truly rare (or inactive)

• Alternate search techniques are desirable: deeper nuclear optical spectroscopic surveys, X-ray stacking, deep radio searches, tidal disruptions (LSST)

MBH-L

Bul

ge

Mar

coni

& H

unt

(200

3)

Greene & Ho 2004

NGC 4395

Pox 52

5 mag

GALFITPeng et al. 2002

Greene, Barth, & Ho in prep

PSF + 1 Sersic fit

Barth et al. 2004

Filippenko & Ho 2003

N 1068m

N 4261

N 821

N 1023

N 2778

N 3115

N 3377N 3379

N 3384

N 3608

N 4291

N 4473

N 4649

N 7457

N 7052g

N 6251g

N 2787G

M87G

IC 1459

N 3245

N 4697N 4596g

N 4564

N 4459g

N 4258m

M 32 M31

MW

MBH

MGal

Monte Carlo

•Distribution of MBH, L, z

‣Corresponding galaxy luminosities using MBH-Lbulge relations

‣Realistic S/N using SDSS

‣Spectroscopic completeness using simulations

Unreliable BH Masses

Bulge/Total ratio poorly constrained

for low-mass BHs

z=0.02 z=0.05 z=0.1

L bol/L

Ed

d =

0.0

1L b

ol/L

Ed

d =

0.1

L bol/L

Ed

d =

1

z=0.05 z=0.02 z=0.1 L

/LEdd=

0.0

1L/

L Edd=

0.1

L/L E

dd=

1

log (MBH/M⦿)4 6 8 4 6 8 4 6 8

Real incompletenessat the low-mass end

ORbiased galaxy sample

ORlow-mass BHs are quiescent

Maximum-Likelihood

Contaminants

Contaminants

Contaminants

Marconi et al. 2004

Which BHs are growingToday?

Heckman et al. 2004

Narrow-line AGNs

SDSS Galaxies

Fundamental Plane?