For refcode 2007ApJ...660..267B: Retrieve 24 NED objects in this reference. Please click here for ADS abstract
NED Abstract
Copyright by American Astronomical Society.
Reproduced by permission
2007ApJ...660..267B
Selection Bias in the M_blackhole_{sigma} and M_blackhole_L Correlations
and Its Consequences
Mariangela Bernardi, Ravi K. Sheth, Elena Tundo, and Joseph B. Hyde
Abstract. It is common to estimate black hole abundances by using a
measured correlation between black hole mass and another more easily
measured observable, such as the velocity dispersion or luminosity of
the surrounding bulge. The correlation is used to transform the
distribution of the observable into an estimate of the distribution of
black hole masses. However, different observables provide different
estimates; the M_blackhole_{sigma} relation predicts fewer massive
black holes than does the M_blackhole_L relation. This is because the
{sigma}L relation in black hole samples currently available is
inconsistent with that in the SDSS sample, on which the distributions of
L or {sigma} are based; the black hole samples have smaller L for a
given {sigma} or have larger {sigma} for a given L. This is true whether
L is estimated in the optical or in the NIR. If this is a selection
rather than physical effect, then the M_blackhole_{sigma} and
M_blackhole_L relations currently in the literature are also biased
from their true values. We provide a framework for describing the effect
of this bias. We then combine it with a model of the bias to make an
estimate of the true intrinsic relations. If we have correctly modeled
the selection effect, then our analysis suggests that the bias in the
<M_blackhole_{sigma}> relation is likely to be small, whereas the
<M_blackhole_L> relation is biased toward predicting more massive black
holes for a given luminosity, and the M_blackhole_L relation is
entirely a consequence of more fundamental relations between
M_blackhole_ and {sigma} and between {sigma} and L. The intrinsic
relation we find suggests that at fixed luminosity, older galaxies tend
to host more massive black holes.
Retrieve 24 NED objects in this reference. Please click here for ADS abstract
