The Density Profile of Local Ellipticals as Violently Relaxed, Collisionless, Dissipationless Systems

摘要

In a series of recent papers, a new formalism has been developed thatexplains the inner structure of dark matter halos as collisionless,dissipationless systems assembled through mergers and accretion at the typicalcosmological rate. Nearby ellipticals are also collisionless, dissipationlesssystems assembling their mass through mergers, but contrarily to the formerstructures they do not continuously accrete external matter because they areshielded by their host halos. Here we explore the idea that the infall of theirown matter ejected within the halo on the occasion of a violent merger can playa role similar to external accretion in halos. The predicted stellar massdensity profile fits the observed one, and the empirical total mass densityprofile is also recovered.