Dark Matter-baryon segregation in the non-linear evolution of coupled Dark Energy model

Abstract

The growth and virialization of spherical top-hat fluctuations, in coupled Dark Energy models, causes segregation between Dark Matter (DM) and baryons, as the gravitational infall into the potential well proceeds more slowly for the baryons than for DM. As a consequence, after attaining their turn-around and before full virialization, halos have outer layers rich of baryons. Accordingly, a natural ambiguity exists on the definition of the virial density contrast. In fact, when the outer baryon layers infall onto the DM-richer core, they carry with them DM materials outside the original fluctuation; hence, no time exists when all materials originally belonging to the fluctuation -and only them- have virialized. Baryon-DM segregation can have various astrophysical consequences on different length-scales. The smallest halos may loose up to 50% of the original baryonic contents and become hardly visible. Subhalos in cluster-size halos may loose much baryonic materials, which could then be observed as intra-cluster light. Isolated halos, in general, can be expected to have a baryon component richer than the cosmological proportions, due to the cosmic enrichement of baryons lost in small halo encounters.

22 pages, 9 figures, accepted version: comparison with a different potential provided, new figures and references added

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Cited by in corpus (17)

• Hydrodynamical N-body simulations of coupled dark energy cosmologies
• Mass functions in coupled Dark Energy models
• Supernova Ia and Galaxy Cluster Gas Mass Fraction Constraints on Dark Energy
• On the Magnitude of Dark Energy Voids and Overdensities
• Non-linear Matter Spectra in Coupled Quintessence
• Probing Dark Energy at Galactic and Cluster Scales
• Gravitational Lensing Constraints on Dynamical and Coupled Dark Energy
• Dark energy from dark radiation in strongly coupled cosmologies with no fine tuning
• Hydrodynamical simulations of coupled and uncoupled quintessence models II: Galaxy clusters
• Scalar field-perfect fluid correspondence and nonlinear perturbation equations
• Modifying Gravity at Low Redshift
• Simulations of structure formation in interacting dark energy cosmologies
• Strongly Coupled Dark Energy Cosmologies yielding large mass Primordial Black Holes
• New observational constraints on interacting dark energy using galaxy clusters virial equilibrium states
• Voids and overdensities of coupled Dark Energy
• Growth and dissolution of spherical density enhancements in SCDEW cosmologies
• Coupled DM heating in SCDEW cosmologies