Lyman Alpha Driven Outflows Around Star Forming Galaxies

Understand

We present accurate Monte-Carlo calculations of Lyman Alpha (hereafter Lya) radiation pressure in a range of models which represent galaxies during various epochs of our Universe.

• We show that the radiation force that Lya photons exert on hydrogen gas in the neutral intergalactic medium (IGM), that surrounds minihalos that host the first stars, may exceed gravity by orders of magnitude and drive supersonic winds.
• Lya radiation pressure may also dominate over gravity in the neutral IGM that surrounds the HII regions produced by the first galaxies.
• However, the radiation force is likely too weak to result in supersonic outflows in this case.