2024/02/29 by Adi Nusser, Nusser, Adi · 1 citation
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Experimental Learning in Engineering #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2402.18942
openalex publication_date 2024/02/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The evolution of halos with masses around M_\textrmh ≈ 1011 \textrmM_\odot and M_\textrmh ≈ 1012 \textrmM_\odot at redshifts z>9 is examined using constrained N-body simulations. The average specific mass accretion rates, M_\textrmh / M_\textrmh, exhibit minimal mass dependence and generally agree with existing literature. Individual halo accretion histories, however, vary substantially. About one-third of simulations reveal an increase in M_\textrmh around z≈ 13. Comparing simulated halos with observed galaxies having spectroscopic redshifts, we find that for galaxies at z\gtrsim9, the ratio between observed star formation rate (SFR) and M_\textrmh is approximately 2%. This ratio remains consistent for the stellar-to-halo mass ratio (SHMR) but only for z\gtrsim 10. At z≃ 9, the SHMR is notably lower by a factor of a few. At z\gtrsim10, there is an agreement between specific star formation rates (sSFRs) and M_\textrmh / M_\textrmh. However, at z≃ 9, observed sSFRs exceed simulated values by a factor of two. It is argued that the mildly elevated SHMR in high-z halos with M_\textrmh ≈ 1011 M\odot, can be achieved by assuming the applicability of the local Kennicutt-Schmidt law and a reduced effectiveness of stellar feedback due to deeper gravitational potential of high-z halos of a fixed mass.