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On the inconsistency between the On the inconsistency between the SMBH Mass Function from velocity SMBH Mass Function from velocity
dispersion and luminositydispersion and luminosity
E. TundoE. Tundo1,21,2, M. Bernardi, M. Bernardi22, R. K. Sheth, R. K. Sheth22
J. B. HydeJ. B. Hyde22, A. Pizzella, A. Pizzella11
(1) Dipartimento di Astronomia, Universitá di Padova, Italy(2) Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
June 2nd, Ohio State University GLCW8
Search for SMBHsSearch for SMBHs
Class of Objects: Quiescent Galaxies AGNs
Primary methods: Stellar kinematics Megamasers Gas kinematics Reverberation Mapping
Today we have about 50 detections, but only three are SURE detections of SMBHs
SMBHs correlationsFundamental empirical relations:
Mbh - Lbulge ; Mbh - σ*
Figure from Gebhardt et al. (2000); but see also Ferrarese & Merritt (2000), Tremaine et al. (2002), Magorrian et al. (1998)
What can we learn from What can we learn from these correlations?these correlations?
Black holes and galaxy formation/evolution are linked
We can obtain local black hole mass function, Φ(Mbh), from measures of velocity dispersion or luminosity
● Φ(Mbh) is needed as a cosmological test for modern models for formation and evolution of galaxies.
SMBHs mass function:: scaling scaling relationsrelations
Mbh-σ, Mbh-L relations from Häring & Rix (2004) early type sample
log(Mbh)=(8.21±0.06)+(3.83±0.21)∙log(/200) Σ=0.22±0.06 dex
log(Mbh)=(8.68±0.10)-(1.30±0.15)(Mr+22)/2.5 Σ=0.34±0.09 dex
Comparation of Φ(>Mbh) from the two predictors
More than an order of magnitude of difference at 109.3 Mbh/M☼ !
Blanton+Hyde, with scatter
Sheth+bulge, with scatter
From velocity dispersion
From luminosity
Tundo, E., Bernardi, M., Sheth, R. K., Hyde, J. B., Pizzella, A. 2006, ApJ in press (astro-ph/0609297)
We obtain different Φ(>Mbh) even starting from the same luminosity function!
Comparation of Φ(>Mbh) from the two predictors
From L to Mbh
From L to σ to Mbh
Sheth et al. 2003 + bulges
Tundo, E., Bernardi, M., Sheth, R. K., Hyde, J. B., Pizzella, A. 2006, ApJ in press (astro-ph/0609297)
L-based and σ-based cumulative mass functions should give the same result:Φ(M•)=∫Φ(O)p(M•|O)dOIf this is not, something is wrong!
L Mbh
σ
Slope s of σ-L relation is different in SDSS and Häring&Rix sample:
sHR = -0.14
sSDSS = -0.1Tundo, E., Bernardi, M., Sheth, R. K., Hyde, J. B., Pizzella, A. 2006, ApJ in press (astro-ph/0609297)
A selection effect in the local SMBHs sample
Tundo, E, Bernardi, M, Sheth, R. K., Hyde, J. B., Pizzella, A. 2006, ApJ in press
(astro-ph/0609297)
Taking into account the bias…
If we ‘brutally’ correct Ls to make them follow the SDSS L-σ relations, and refit Mbh-L the two predictor give the same cumulative mass function.
Simulations
Bernardi, M., Sheth, R. K., Tundo, E., Hyde, J. B. 2006, ApJ in press (astro-ph/0609300)
An empirical model for the selection effect let us reproduce observed relations Mbh-σ, Mbh-L, σ-L
Agreement is non trivial: a change of 5% in selection parameters produce significative differences.
Bernardi, M., Sheth, R. K., Tundo, E., Hyde, J. B. 2006, ApJ (astro-ph/0609300)
Simulations
σ –based Φ(>Mbh) is in better agreement with intrinsic distribution.
ConclusionsConclusionsL-based and σ-based cumulative mass
function are different, because the L-σ relation is different for the sample in which we measure Mbh-L and Mbh-σ correlations.
If it is caused by selection effects, this bias affects mailnly the luminosity, so it could be safer to use σ-based SMBH mass function.
……. Thank you!!!!!