Warm Dark Matter Constraints Using Milky-Way Satellite Observations and Subhalo Evolution Modeling
| Autor: | Dekker, Ariane, Ando, Shin'ichiro, Correa, Camila A., Ng, Kenny C. Y. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 106, 123026 (2022) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.106.123026 |
| Popis: | Warm dark matter (WDM) can potentially explain small-scale observations that currently challenge the cold dark matter (CDM) model, as warm particles suppress structure formation due to free-streaming effects. Observing small-scale matter distribution provides a valuable way to distinguish between CDM and WDM. In this work, we use observations from the Dark Energy Survey and PanSTARRS1, which observe 270 Milky-Way satellites after completeness corrections. We test WDM models by comparing the number of satellites in the Milky Way with predictions derived from the Semi-Analytical SubHalo Inference ModelIng (SASHIMI) code, which we develop based on the extended Press-Schechter formalism and subhalos' tidal evolution prescription. We robustly rule out WDM with masses lighter than 4.4 keV at 95% confidence level for the Milky-Way halo mass of $10^{12} M_\odot$. The limits are a weak function of the (yet uncertain) Milky-Way halo mass, and vary as $m_{\rm WDM}>3.6$-$5.1$ keV for $(0.6$-$2.0) \times 10^{12} M_\odot$. For the sterile neutrinos that form a subclass of WDM, we obtain the constraints of $m_{\nu_s}>11.6$ keV for the Milky-Way halo mass of $10^{12} M_{\odot}$. These results based on SASHIMI do not rely on any assumptions of galaxy formation physics or are not limited by numerical resolution. The models, therefore, offer a robust and fast way to constrain the WDM models. By applying a satellite forming condition, however, we can rule out the WDM mass lighter than 9.0 keV for the Milky-Way halo mass of $10^{12} M_\odot$. Comment: 14 pages, 8 figures; Comments welcome. v2: Accepted for publication in PRD |
| Databáze: | arXiv |
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