Black Hole Growth in the Local Universe

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Black Hole Growth in the Local Universe

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

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Local BH Mass Functions
Galaxy luminosity function?BH mass function
Primary mode of BH growth AGN lifetimes,
radiative efficiency
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BHs Growing Today
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Only means to probe this regime is using AGNs,
since current resolution inadequate for dynamical
detection
But isnt this a neglible fraction of total BH
mass and radiated lumiminosity?
Haehnelt 2004
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Disproportionate Import
Gravitational radiation
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Low-mass BHs are rare?
Greene Ho 2004 found only 19 broad-line AGNs
in DR1 (lt106 M?)
All galaxies
Active galaxies (narrow-line)
Groves et al. astroph/0607311
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The Search

• zlt0.35 broad-line AGNs from SDSS
• Galaxy Survey r lt 17.77 extended (e.g. Hao et
  al. 2005, Heckman et al. 2004)
• AGN Survey 15 lt i lt 19.1 color-selected

Modeling (Greene Ho 2004)
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Greene Ho in prep
SDSS bright limit
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Ha Luminosity Function
Greene Ho in prep
Contaminants
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BH Mass Functions
Greene Ho in prep
Text
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Monte Carlo
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19 AGNs (lt106 M?) Greene Ho 2004HST/ACS F435W
(B), F814W (I), 1 orbit/source
Greene, Barth, Ho in prep
7 kpc
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GALFIT Peng et al. 2002
PSF 1 Sersic fit
Barth et al. 2004
Filippenko Ho 2003
Greene, Barth, Ho in prep
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Lauer et al. 2006/astroph0606739
Ferrarese et al. 2006
Star-cluster mass correlated with galaxy mass
(see also Wehner Harris 2006, Rossa et al. 2006)
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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 (lt106 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)

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GALFIT Peng et al. 2002
PSF 1 Sersic fit
Barth et al. 2004
Filippenko Ho 2003
Greene, Barth, Ho in prep
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Monte Carlo

• Distribution of MBH, L, z
• Corresponding galaxy luminosities using
  MBH-Lbulge relations
• Realistic S/N using SDSS
• Spectroscopic completeness using simulations

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Unreliable BH Masses
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z0.02
z0.05
z0.1
Lbol/LEdd 0.01
Lbol/LEdd 0.1
Lbol/LEdd 1
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Maximum-Likelihood
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Contaminants
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Contaminants
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Contaminants
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Marconi et al. 2004
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Which BHs are growingToday?
Narrow-line AGNs
SDSS Galaxies
Heckman et al. 2004
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Fundamental Plane?