From Wikipedia, the free encyclopedia

In astronomy, the Kennicutt–Schmidt law is an empirical relation between the surface gas density and star formation rate (SFR) in a given region. [1] The relation was first examined by Maarten Schmidt in a 1959 paper [2] where he proposed that the SFR surface density scales as some positive power of the local gas surface density. i.e.

.

In general, the SFR surface density is in units of solar masses per year per square parsec and the gas surface density in grams per square parsec . Using an analysis of gaseous helium and young stars in the solar neighborhood, the local density of white dwarfs and their luminosity function, and the local helium density, Schmidt suggested a 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.

In 1989, Robert Kennicutt found that the H intensities in a sample of 15 galaxies could be fit with the earlier Schmidt relations with a power law index of . [3] More recently, he examined the connection between surface gas density and SFR for a larger set of galaxies to estimate a value of . [4] [5]

References

  1. ^ The name "Schmidt law" is now commonly used for a general relation between volume gas density and star formation rate, and the Kennicutt-Schmidt law for the surface gas density and star formation rate.
  2. ^ Schmidt, Maarten (1959). "The Rate of Star Formation". The Astrophysical Journal. 129: 243. Bibcode: 1959ApJ...129..243S. doi: 10.1086/146614.
  3. ^ Kennicutt, Robert C. Jr. (1989). "Star Formation Law in Galactic Disks". The Astrophysical Journal. 344 (2): 685. Bibcode: 1989ApJ...344..685K. doi: 10.1086/167834.
  4. ^ Kennicutt, Robert C. Jr. (1998). "The Global Schmidt Law in Star-forming Galaxies". The Astrophysical Journal. 498 (2): 541–552. arXiv: astro-ph/9712213. Bibcode: 1998ApJ...498..541K. doi: 10.1086/305588. S2CID  250812069.
  5. ^ Kennicutt, Robert C. Jr.; Evans, Neal II (2012). "Star Formation in the Milky Way and Nearby Gaalxies". Annual Review of Astronomy & Astrophysics. 50: 531–585. arXiv: 1204.3552v2. Bibcode: 2012ARA&A..50..531K. doi: 10.1146/annurev-astro-081811-125610. S2CID  118667387.
From Wikipedia, the free encyclopedia

In astronomy, the Kennicutt–Schmidt law is an empirical relation between the surface gas density and star formation rate (SFR) in a given region. [1] The relation was first examined by Maarten Schmidt in a 1959 paper [2] where he proposed that the SFR surface density scales as some positive power of the local gas surface density. i.e.

.

In general, the SFR surface density is in units of solar masses per year per square parsec and the gas surface density in grams per square parsec . Using an analysis of gaseous helium and young stars in the solar neighborhood, the local density of white dwarfs and their luminosity function, and the local helium density, Schmidt suggested a 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.

In 1989, Robert Kennicutt found that the H intensities in a sample of 15 galaxies could be fit with the earlier Schmidt relations with a power law index of . [3] More recently, he examined the connection between surface gas density and SFR for a larger set of galaxies to estimate a value of . [4] [5]

References

  1. ^ The name "Schmidt law" is now commonly used for a general relation between volume gas density and star formation rate, and the Kennicutt-Schmidt law for the surface gas density and star formation rate.
  2. ^ Schmidt, Maarten (1959). "The Rate of Star Formation". The Astrophysical Journal. 129: 243. Bibcode: 1959ApJ...129..243S. doi: 10.1086/146614.
  3. ^ Kennicutt, Robert C. Jr. (1989). "Star Formation Law in Galactic Disks". The Astrophysical Journal. 344 (2): 685. Bibcode: 1989ApJ...344..685K. doi: 10.1086/167834.
  4. ^ Kennicutt, Robert C. Jr. (1998). "The Global Schmidt Law in Star-forming Galaxies". The Astrophysical Journal. 498 (2): 541–552. arXiv: astro-ph/9712213. Bibcode: 1998ApJ...498..541K. doi: 10.1086/305588. S2CID  250812069.
  5. ^ Kennicutt, Robert C. Jr.; Evans, Neal II (2012). "Star Formation in the Milky Way and Nearby Gaalxies". Annual Review of Astronomy & Astrophysics. 50: 531–585. arXiv: 1204.3552v2. Bibcode: 2012ARA&A..50..531K. doi: 10.1146/annurev-astro-081811-125610. S2CID  118667387.

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