constraints on broad line quasar black hole masses, eddington ratios, and lifetimes
DESCRIPTION
Constraints on Broad Line Quasar Black Hole Masses, Eddington Ratios, and Lifetimes. Brandon C. Kelly (CfA) Marianne Vestergaard (DARK, Denmark), Xiaohui Fan (Arizona), Philip Hopkins (Berkeley), Lars Hernquist (CfA), & Aneta Siemiginowska (CfA). Black Hole Growth and Galaxy Evolution. - PowerPoint PPT PresentationTRANSCRIPT
Constraints on Broad Line Quasar Black Hole Masses, Eddington
Ratios, and Lifetimes
Brandon C. Kelly (CfA)
Marianne Vestergaard (DARK, Denmark), Xiaohui Fan (Arizona), Philip Hopkins (Berkeley), Lars Hernquist
(CfA), & Aneta Siemiginowska (CfA)
3/10/10 Brandon Kelly, [email protected]
Black Hole Growth and Galaxy Evolution
Black Hole Growth and Galaxy Evolution
• Tight correlation between MBH and host galaxy bulge properties implies that supermassive black holes (SMBH) and galaxy evolution is linked (e.g., Merritt & Ferrarese 2001, Tremaine et al. 2002)
• Can be explained if black hole growth is self-regulated (e.g., Wyithe & Loeb 2003, Di Matteo et al. 2005)
• If growth is SR, then broad line phase for bright quasars occurs at end of growth
3/10/10 Brandon Kelly, [email protected]
Aller & Richstone (2007)
What do We Hope to Learn from Studying the Broad Line Quasar SMBH Mass and Eddington Ratio Distributions?
What do We Hope to Learn from Studying the Broad Line Quasar SMBH Mass and Eddington Ratio Distributions?
• Distribution and Evolution of SMBH Mass and L / Ledd is a fundamental observational quantity for comparing with theoretical models
• Can compare with local mass function of all SMBHs to estimate lifetime of BLQSO phase
• Investigate how much growth occurs during BLQSO phases, test self-regulated growth model
3/10/10 Brandon Kelly, [email protected]
Correcting for Mass Uncertainty and Incompleteness (Kelly et al. 2009)
Correcting for Mass Uncertainty and Incompleteness (Kelly et al. 2009)
3/10/10 Brandon Kelly, [email protected]
• Can derive mass estimates from L and FWHM (e.g., Vestergaard & Peterson 2006)
• Mass estimates have a large statistical scatter (~0.4 dex), broaden inferred BHMF
• Complicated incompleteness, even high mass end can be incomplete
Sample SummarySample Summary
• Used the SDSS DR3 Sample of Richards et al. (2006) with measurements taken from Vestergaard et al.(2008)
• Only kept objects at 1 < z < 4.5• Used Mg II for 1 < z < 1.6, and C IV for z > 1.6• Left with ~ 10,000 sources
3/10/10 Brandon Kelly, [email protected]
Quasar BHMF at 1 < z < 4.5Quasar BHMF at 1 < z < 4.5
3/10/10 Brandon Kelly, [email protected]
Black Solid: Our Estimated BHMFsGreen Solid: Best-fit BHMFDashed Black : Local BHMF for all SMBHs (Merloni & Heinz 2008)Red Solid: BHMF from Vestergaard et al.(2008)
Volonteri & Natarajan (2009)Volonteri & Natarajan (2009)
Eddington Ratio Distribution and Fractional Growth
Eddington Ratio Distribution and Fractional Growth
3/10/10 Brandon Kelly, [email protected]
Most Broad Line Quasars are not accreting at or near the Eddington Limit
Most Broad Line Quasars are not accreting at or near the Eddington Limit
Most of the contribution to the localBH mass density is from objects that we currently see as obscured
Most of the contribution to the localBH mass density is from objects that we currently see as obscured
Inferred Lifetime of Broad Line PhaseInferred Lifetime of Broad Line Phase
3/10/10 Brandon Kelly, [email protected]
• Lifetime too short to grow a BH seed of MBH ~ 106 MSUN to MBH ~ 109 MSUN
• Lifetime + L / Ledd Distribution Imply that most growth occurred in an earlier obscured phase of Eddington-limited growth
• Lifetime too short to grow a BH seed of MBH ~ 106 MSUN to MBH ~ 109 MSUN
• Lifetime + L / Ledd Distribution Imply that most growth occurred in an earlier obscured phase of Eddington-limited growth
Maximum Mass of a SMBHMaximum Mass of a SMBH
3/10/10 Brandon Kelly, [email protected]
• If SMBH growth is self-regulated, this should be representative of the most massive SMBH
• Consistent with maximum mass seen in cosmological simulations (Sijacki et al. 2009) and that expected from self-regulation arguments (Natarajan & Treister 2009)
• If SMBH growth is self-regulated, this should be representative of the most massive SMBH
• Consistent with maximum mass seen in cosmological simulations (Sijacki et al. 2009) and that expected from self-regulation arguments (Natarajan & Treister 2009)
Sijacki et all (2009)
Summary• First work to rigorously and self-consistently correct
for statistical uncertainty and incompleteness in the broad line quasar mass function
• BLQSO BHMF qualitatively in agreement with cosmological model of self-regulated black hole growth
• Most BL quasars are not accreting at or near L / Ledd
• SMBHs cannot experience all of their growth in a BL phase
• Maximum SMBH mass is ~ 1010 – 1011 MSUN
• Uncertainty in mass estimates may be ~ 0.2 dex, or correlated with luminosity
3/10/10 Brandon Kelly, [email protected]
How uncertain are the Mass Estimates?
How uncertain are the Mass Estimates?
Assuming Scatter of 0.4 dexAssuming Scatter of 0.4 dex When we fit the ScatterWhen we fit the Scatter
3/10/10 Brandon Kelly, [email protected]
Red is the modelDistribution
Black is the observeddistribution
Standard value of 0.4 dex implies a mass estimate distribution that is too broad, implies:
- Statistical error is correlated with luminosity? (Shen & Kelly 2010)- Uncorrected radiation pressure? (Marconi et al. 2008)- Broad line mass estimates are meaningless at this L and z?
Standard value of 0.4 dex implies a mass estimate distribution that is too broad, implies:
- Statistical error is correlated with luminosity? (Shen & Kelly 2010)- Uncorrected radiation pressure? (Marconi et al. 2008)- Broad line mass estimates are meaningless at this L and z?
Future workFuture work
• Incorporate more flexible L / Ledd distribution• Investigate if error in mass estimates is correlated
with luminosity, and include in application to DR7 data set (Shen & Kelly, in prep)
• Apply technique to COSMOS and other multiwavelength data sets to better determine Eddington ratio distribution and BHMF (Kelly & Trump, et al.)
• Reverberation mapping of higher z and L sources to better determine uncertainties (Elvis and Trump, et al.)
3/10/10 Brandon Kelly, [email protected]
Mass-Luminosity Plane
3/10/10 Brandon Kelly, [email protected]
Downsizing of SMBHsDownsizing of SMBHs
3/10/10 Brandon Kelly, [email protected]