Astrophysics (Index)About

Sérsic profile

(Sérsic model, Sérsic law)
(model of the relative surface brightness across a galaxy)

A Sérsic profile (or Sérsic model or Sérsic law) is an equation describing the relative surface brightness of a galaxy (i.e., a surface brightness profile), stating that the log of the surface brightness falls off exponentially with distance from the center. The Sérsic index is the reciprocal of the exponent: i.e., if the exponent is 1/n, then n is the Sérsic index.

log I(R) ∝ R1/n

or

         R1/n
I(R) ∝ e

The Sérsic profile equation is a generalized profile function for which once instance is the de Vaucouleurs' profile (Sérsic profile with an index of 4) and another the exponential profile (index of 1).


(relation,galaxies,surface brightness)
Further reading:
https://en.wikipedia.org/wiki/Sersic_profile
http://www-star.st-and.ac.uk/~spd3/Teaching/AS3011/AS3011_5.pdf

Referenced by pages:
de Vaucouleurs' profile
surface brightness profile

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