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!!!!!