# Schmidt Law

Schmidt (1959) speculated that the star formation rate is proportional to a power of the surface density of the interstellar medium

 (3.1)

where the power seems between 1 and 2 around the solar vicinity. If , the star formation rate is thought to be determined by the collision rate of interstellar clouds. At that time Schmidt showed us . On the other hand, if the gas passing through the galactic arms forms stars, the star formation rate seems proportional to the gas surface density and the arm-to-arm period. Thus this predicts .

Subsections

Kohji Tomisaka 2012-10-03