A Model For Intergalactic Filaments and Galaxy Formation During the First Gigayear

Understand

We propose a physically based, analytic model for intergalactic filaments during the first gigayear of the universe.

• The structure of a filament is based upon a gravitationally bound, isothermal cylinder of gas.
• The model successfully predicts for a cosmological simulation the total mass per unit length of a filament (dark matter plus gas) based solely upon the sound speed of the gas component, contrary to the expectation for collisionless dark matter aggregation.
• It argues that the gas, through its hydrodynamic properties, plays a key role in filament structure rather than being a passive passenger in a preformed dark matter potential.