Dissipationless collapse of spherical protogalaxies and the fundamental plane

Abstract

Abstract. Following on from the numerical work of Capelato et al. (1995Capelato et al. ( , 1997, where dissipationless merger simulations were shown to reproduce the "Fundamental Plane" (FP) of elliptical galaxies, we investigate whether the end products of pure, spherically symmetric, one-component dissipationless collapses could also reproduce the FP. Past numerical work on collisionless collapses have addressed important issues on the dynamical/structural characteristics of collapsed equilibrium systems. However, the study of collisionless collapse in the context of the nature of the FP has not been satisfactorily addressed yet. Our aim in this paper is to focus our attention on the resulting collapse of simple one-component spherical models with a range of different initial virial coefficients. We find that the characteristic correlations of the models are compatible with virialized, centrally homologous systems. Our results strengthen the idea that merging may be a fundamental ingredient in forming non-homologous objects.

Merging of low-mass systems and the origin of the Fundamental Plane

“…The tolerance parameter was the same for all simulations, θ= 0.8. As discussed in Dantas et al (2002), the choice of the softening parameter ε is a compromise between spatial resolution and the collisionless condition of the system on evolutionary time‐scales. It thus depends on the particle number N , and on the specific density distribution profile (see also e.g.…”

Covariant version of Verlinde’s emergent gravity

“…Admittedly, an accurate picture of the situation must be more complicated than that because the fluid in general should be a mixture of both fluid and superfluid components and not just suddenly turn entirely superfluid at some point, but such a treatment is beyond the aim of this current work. Also, it would make more sense to use an assumption of (approximate) equilibrium rather than just assuming a time-independent solution, for example using the virial theorem [12].…”

Astrophysics in 2002

“…Beats us, but Seljak (2002) says it must mean that the baryons in galaxies make a significant contribution to the velocities. And ditto for the success of the fundamental plane in describing the relationships of the properties of elliptical galaxies (Dantas et al 2002). What are the relations, you ask?…”