A simple algorithm to predict the Stellar Masses of Nearby Satellites of Galaxies from DMO simulations

Due to the absence of various baryonic processes, Dark Matter Only (DMO) simulations have lower computational and time complexity compared to Hydrodynamical (HYDRO) simulations, although they cannot be used for comparison with observations for the same reason. A prediction tool to assign stellar masses to dark matter halos of DMO simulations would provide a more efficient testing of new dark matter models. The established relationship between halo mass and stellar mass connection lacks accuracy for nearby satellites due to the environmental influence of the host halo, such as gravitational tidal stripping and ram pressure stripping. This project intends to introduce a simple algorithm to assign stellar populations to nearby satellites in DMO simulations, based on relations reliant on more stable properties than Halo mass. To achieve this, we examine differences between DMO and HYDRO simulations, as well as the dependence of the probability distribution and stellar mass of luminous satellites at z = 0 on a more stable 'peak' parameter. We then obtain distinct relations constructing a straightforward map to obtain stellar mass functions and radial distribution of luminous satellites. This algorithm's simplicity initially led to an overestimation of bright halos in large simulations, prompting additional corrections for galaxies with host halo masses of ~ 10¹² M⊙ . The final results indicate that the stellar mass functions and radial distributions directly obtained from HYDRO simulations align well with those predicted solely from DMO simulations using our map, offering cost and complexity reduction, facilitating the goal for more efficient testing of dark matter models.