| Description |
Dark matter has been theorized to exist for over 80 years based on astronomical observations but has yet to be found in terrestrial experiments. Named for its lack of interaction with the electromagnetic field, dark matter does not absorb, reflect, or emit electromagnetic radiation making it undetectable to us. Because of this characteristic, it is considered one of the greatest current mysteries in astronomy. However, visible galaxies are believed to live inside dark matter halos, which are hypothetical regions that are so dense that the mass of the matter inside them (both dark matter and regular matter) is large enough that the cosmological constant (which is the expansion of the universe) no longer affects it. These visible galaxies are called dwarf satellite galaxies which are smaller galaxies, holding fewer stars and mass. These dwarf galaxies are sometimes close enough to another galaxy to be pulled into the gravity of the larger "host" galaxy which then makes them a satellite in the host's system. In this work, we study the spatial distribution of dwarf galaxies within and outside of their individual host systems to better understand the underlying dynamics within the structure of dark matter halos. The existing body of observational studies predominantly concentrates on host galaxy systems up to the virial radius, as exemplified in studies of our own Milky Way satellites and research such as the Satellites Around Galactic Analogs Survey (SAGA). We use a cosmological simulation called The Very Small Multi Dark Planck Simulation (VSMDPL) to extend our area of focus into the outskirts of the halo in an attempt to observe a correlation between the number of subhalos (as a proxy of dwarf galaxies) in the inner region (within virial radius) and of "nearby halos" in the outskirts of these host systems. We are also using the VSMDPL to investigate whether the radial profile is correlated with host properties. We have found that the number of satellite galaxies within our selected inner and outer regions is not as strongly correlated as expected. We also found that halo properties have different correlations with the radial profile of subhalos. In particular, by calculating the correlation strength at multiple radii, we found that the number of subhalos within the virial radius does not always correlate the strongest with a host property. Our most recent finding is potential evidence for assembly bias within our host halo property graphs, taking effect at approximately 1 Mpc away from our host galaxy. Our analysis will help connect the study of satellite systems to studies about the outskirts of host halos (e.g., splashback radii and assembly bias) and will be influential in predicting the next stage of observational data that will be conducted in the future. |
