Kennicutt-Schmidt Law
Encyclopedia
The Kennicutt-Schmidt is a relation between the gas-density and star-formation rate (SFR) in a given region. The relation was first examined by Maarten Schmidt
in a 1959 paper in which he proposed that the SFR surface density scales as some positive power ('n') of the local gas surface density, i.e.
.
In general the SFR surface density
might be in units of solar-masses per year, per square-parsec 
; and the gas surface density might be in grams per square-parsec 
. Using an analysis of he gas and young-stars in the solar neighborhood, the local density of white dwarfs and their luminosity function
, and the local helium density, Schmidt suggests the value of
(and very likely between 1 and 3). All of the data used were gathered from the Milky Way, and specifically the solar-neighborhood.
More recently, Robert Kennicutt
examined the connection between gas-density and SFR for nearly 100 nearby galaxies to estimate a value of
.
Maarten Schmidt
Maarten Schmidt is a Dutch astronomer who measured the distances of quasars.Born in Groningen, The Netherlands, Schmidt studied with Jan Hendrik Oort. He earned his Ph.D. degree from Leiden Observatory in 1956....
in a 1959 paper in which he proposed that the SFR surface density scales as some positive power ('n') of the local gas surface density, i.e.
.In general the SFR surface density
might be in units of solar-masses per year, per square-parsec ; and the gas surface density might be in grams per square-parsec . Using an analysis of he gas and young-stars in the solar neighborhood, the local density of white dwarfs and their luminosity functionLuminosity function
The luminosity function or luminous efficiency function describes the average visual sensitivity of the human eye to light of different wavelengths. It should not be considered perfectly accurate in every case, but it is a very good representation of visual sensitivity of the human eye and it is...
, and the local helium density, Schmidt suggests the value of
(and very likely between 1 and 3). All of the data used were gathered from the Milky Way, and specifically the solar-neighborhood.More recently, Robert Kennicutt
Robert Kennicutt
Robert Charles Kennicutt, Jr. FRS is an American astronomer. He is the Plumian Professor of Astronomy at the Institute of Astronomy in the University of Cambridge. He was formerly Editor-in-Chief of the Astrophysical Journal...
examined the connection between gas-density and SFR for nearly 100 nearby galaxies to estimate a value of
.