2011/10/20 by Jonathan M. Bittner, Abraham Loeb, Bittner, Jonathan M. +1 · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy and Astrophysical Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.1110.4659
4 pages, 5 figures
arxiv created 2011/10/20 · openalex publication_date 2011/10/20 · arxiv updated 2011/10/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The post-recombination streaming of baryons through dark matter keeps baryons out of low mass (<106 solar masses) halos coherently on scales of a few comoving Mpc. It has been argued that this will have a large impact on the 21-cm signal before and after reionization, as it raises the minimum mass required to form ionizing sources. Using a semi-numerical code, we show that the impact of the baryon streaming effect on the 21-cm signal during reionization (redshifts z approximately 7-20) depends strongly on the cooling scenario assumed for star formation, and the corresponding virial temperature or mass at which stars form. For the canonical case of atomic hydrogen cooling at 104 Kelvin, the minimum mass for star formation is well above the mass of halos that are affected by the baryon streaming and there are no major changes to existing predictions. For the case of molecular hydrogen cooling, we find that reionization is delayed by a change in redshift of approximately 2 and that more relative power is found in large modes at a given ionization fraction. However, the delay in reionization is degenerate with astrophysical assumptions, such as the production rate of UV photons by stars.