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.