Unifying the Scaling Relations in Galactic Bulges – an Implication of Bulge Formation

Aims: I present the derivation of some important scaling relations in galactic bulges by using a simple model of bulge formation.

Methodology: If the radiation pressure of the bulge suppresses its accretion of mass, together with the bulge luminosity-mass relation and the supermassive black hole (SMBH)- velocity dispersion relation, we can obtain a set of scaling relations such as those relating the mass of SMBH to bulge mass and luminosity, the Faber-Jackson and the fundamental plane relations.

Results: All these derived scaling relations agree with the empirical fittings from the observations.

Conclusion: All the scaling relations derived are consistent with the observational data. Therefore, the radiation pressure of the bulge provides a significant role to connect all the scaling relations together.