2017/06/30 by Shingo Hirano, James M. Sullivan, Volker Bromm · 1 citation
Physics and Astronomy · #Astrophysics #Axion #Cold dark matter #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Lambda #Particle physics #Physics #Quantum mechanics #Redshift #Stars #Universe #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1093/mnrasl/slx146
5 pages, 1 table, 3 figures, accepted for publication in MNRAS
arxiv created 2017/09/22 · openalex publication_date 2017/09/22 · arxiv updated 2017/09/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract The formation of the first stars in the high-redshift Universe is a sensitive probe of the small-scale, particle physics nature of dark matter (DM). We carry out cosmological simulations of primordial star formation in ultralight, axion-like particle DM cosmology, with masses of 10−22 and 10−21 eV, with de Broglie wavelengths approaching galactic scales (∼ kpc). The onset of star formation is delayed, and shifted to more massive host structures. For the lightest DM particle mass explored here, first stars form at z ∼ 7 in structures with ∼109 M⊙, compared to the standard minihalo environment within the Λ cold dark matter (ΛCDM) cosmology, where z ∼ 20–30 and ∼105–106 M⊙. Despite this greatly altered DM host environment, the thermodynamic behaviour of the metal-free gas as it collapses into the DM potential well asymptotically approaches a very similar evolutionary track. Thus, the fragmentation properties are predicted to remain the same as in ΛCDM cosmology, implying a similar mass scale for the first stars. These results predict intense starbursts in the axion cosmologies, which may be amenable to observations with the James Webb Space Telescope.