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On the inconsistency between the SMBH Mass Function from velocity dispersion and luminosity E. Tundo 1,2, M. Bernardi 2, R. K. Sheth 2 J. B. Hyde 2, A. Pizzella 1 J. B. Hyde 2, A. Pizzella 1 (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
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Search 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
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SMBHs correlations Fundamental empirical relations: M bh - L bulge ; M bh - σ * Figure from Gebhardt et al. (2000); but see also Ferrarese & Merritt (2000), Tremaine et al. (2002), Magorrian et al. (1998)
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What can we learn from these correlations? Black holes and galaxy formation/evolution are linked We can obtain local black hole mass function, Φ(M bh ), from measures of velocity dispersion or luminosity ● Φ(M bh ) is needed as a cosmological test for modern models for formation and evolution of galaxies.
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: scaling relations SMBHs mass function: scaling relations M bh -σ, M bh -L relations from Häring & Rix (2004) early type sample log(M bh )=(8.21±0.06)+(3.83±0.21)∙log( /200) Σ=0.22±0.06 dex log(M bh )=(8.68±0.10)-(1.30±0.15)(M r +22)/2.5 Σ=0.34±0.09 dex
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Comparation of Φ(>M bh ) from the two predictors More than an order of magnitude of difference at 10 9.3 M bh /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)
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We obtain different Φ(>M bh ) even starting from the same luminosity function! Comparation of Φ(>M bh ) 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)dO If this is not, something is wrong! L M bh σ
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Slope s of σ-L relation is different in SDSS and Häring&Rix sample: s HR = -0.14 s SDSS = -0.1 Tundo, 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
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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 M bh -L the two predictor give the same cumulative mass function.
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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 M bh -σ, M bh -L, σ-L Agreement is non trivial: a change of 5% in selection parameters produce significative differences.
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Bernardi, M., Sheth, R. K., Tundo, E., Hyde, J. B. 2006, ApJ (astro-ph/0609300) Simulations σ –based Φ(>M bh ) is in better agreement with intrinsic distribution.
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Conclusions L-based and σ-based cumulative mass function are different, because the L-σ relation is different for the sample in which we measure M bh -L and M bh -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!!!!!
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