Correlation of black hole and bulge masses: driven by energy but correlated with momentum.

We use a recent sample of 49 galaxies to show that there is a proportionality relation between the black hole mass and the quantity , where is mass of the spheroidal stellar component and is the stellar velocity dispersion. is called the momentum parameter and the ratio is . This result is applied to the penetrating-jet feedback model which argues that the correlation that holds is with a momentum-like parameter, although this feedback mechanism is based on energy balance. [ABSTRACT FROM AUTHOR]