Figure 8

Baryonic mass available for star formation in minihalos in a cosmological simulation that includes streaming velocities. The circles, stars, and triangles denote the outcome for Mach numbers 0, 1.9, and 3.8 at \(z=20\), respectively, and the black dashed line shows the gas mass assuming a cosmological baryon to dark matter ratio. As the streaming velocity is increased, the halos retain less gas, the central gas density is reduced, and less gas is able to cool and form stars. The degree to which star formation is suppressed increases with decreasing halo mass. Since the streaming velocities are sourced by acoustic oscillations before recombination, this leads to a modulation of Population III star formation on \({\simeq}10\mbox{-}100\mbox { Mpc}\) scales. Adapted from O’Leary and McQuinn (2012).