Astrophysics (Index)About

Faber-Jackson relation

(FJR)
(relation between elliptical galaxy luminosity and stellar velocity dispersion)

The Faber-Jackson relation (FJR) is a relation between the luminosity of an elliptical galaxy and its central stellar velocity dispersion. It is something like a "Tully-Fisher relation for elliptical galaxies", serving as a method of estimating the distance to a galaxy: the velocity dispersion can be derived from spectrography, by observing the effects of redshift and blue shift on spectral lines of the stars, and given that, the relation yields a rough absolute magnitude of the galaxy. Having both the absolute and apparent magnitude of the galaxy, the distance can be estimated.

A more recently-observed, useful relation, the D-σ relation (aka Sigma-D relation) associates the diameter of an elliptical galaxy with its velocity dispersion. The fundamental plane is an even later development: a relation between radius, velocity dispersion, and surface brightness, which may yield an even better distance estimate through use of an additional observable.


(relation,galaxies,luminosity)
Further reading:
https://en.wikipedia.org/wiki/Faber-Jackson_relation
https://en.wikipedia.org/wiki/Cosmic_distance_ladder#Sigma-D_relation
http://spiff.rit.edu/classes/phys372/lectures/fj/fj.html
http://burro.case.edu/Academics/Astr222/Galaxies/Elliptical/kinematics.html
https://www.astro.umd.edu/~richard/ASTRO620/ellipticals_psu.pdf
https://ui.adsabs.harvard.edu/abs/1976ApJ...204..668F/abstract

Referenced by pages:
cosmic distance ladder
standard candle

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