Weak Hopf algebra

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In astronomy, the Kennicutt–Schmidt (or simply the Schmidt \lLaw) is an empirical 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.[1] i.e.

ΣSFR(Σgas)n.

In general the SFR surface density (ΣSFR) is in units of solar masses per year per square parsec (Myr1pc2) and the gas surface density in grams per square parsec (gpc2). 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 n2 (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 n=1.4±0.15.[2]

References

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