Partialhalos

Partialhalos are a concept within the field of computational physics, specifically in simulations of cosmic structure formation. They represent an incomplete or substructure within a larger dark matter halo. In the hierarchical model of structure formation, smaller dark matter halos merge to form larger ones. A partialhalo can be thought of as a progenitor halo that has not yet been fully assimilated into its parent halo, or a substructure that retains some level of distinct identity.

These partialhalos are important for understanding the complex internal structure of massive dark matter halos, which are not smooth but rather contain numerous smaller clumps and subhalos. Identifying and characterizing partialhalos can provide insights into the merger history and dynamical evolution of these large structures. Simulations track the formation and evolution of these structures, and partialhalos are a natural consequence of this process. Their presence can influence the distribution of baryonic matter within a halo, affecting galaxy formation and evolution.

The study of partialhalos helps refine cosmological models and improve the accuracy of simulations. It highlights the dynamic and complex nature of dark matter halos beyond their idealized spherical representations. Researchers analyze simulation data to identify regions that exhibit characteristics of partialhalos, such as distinct density peaks or ongoing accretion streams, to better understand the building blocks of cosmic structures.