An Etymological Dictionary of Astronomy and Astrophysics

A power-law relation between → star formation rate (SFR) and a corresponding measure of gas density. For external galaxies it is usually expressed in terms of the observable surface density of gas (Σ_gas):

SFR ∝ Σ_gasⁿ. The exponent n is determined to be 1.4 ± 0.15 (Kennicutt 1998, ApJ 498, 541). The validity of the Schmidt law has been tested in dozens of empirical studies.

The Schmidt law provides a tight parametrization of the global star formation law, extending over several orders of magnitude in SFR and gas density.

See also: Named after Maarten Schmidt (1929-), a dutch-born American astronomer, who also discovered the first → quasar (3C 273) in 1963.