Properties of resonantly produced sterile neutrino dark matter subhaloes

The anomalous 3.55 keV X-ray line recently detected towards a number of dark matter objects may be interpreted as the radiative decays of 7.1 mass sterile neutrino dark matter. Depending on its parameters, the sterile can range from cold to warm dark matter with small-scale suppression differs in form from commonly-adopted thermal warm dark matter. Here, we investigate the subhalo properties for 7.1 keV sterile neutrino matter produced via the resonant Shi-Fuller mechanism. Using accurate power spectra, we run cosmological zoom-in simulations of a Milky-sized halo and explore the abundance of massive subhalos, their radial, and their internal structure. We also simulate the halo with 2.0 keV warm dark matter for comparison and discuss quantitative. We find that the resonantly produced sterile neutrino model for 3.55 keV line provides a good description of structures in the Local Group, the number of satellite dwarf galaxies and their radial distribution, largely mitigates the too-big-to-fail problem. Future searches for galaxies by deep surveys, such as the Dark Energy Survey, Large Survey Telescope, and Wide Field Infrared Survey Telescope, will be a direct test of warm dark matter scenarios.