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planetary nebula luminosity function

(PNLF)
(model used in distance estimation)

The planetary nebula luminosity function (PNLF) is a model consisting of a (non-normalized) probability density function of the luminosity of planetary nebulae. With it, planetary nebulae are used as standard candles, using the fact that there is a (rough) maximum brightness of planetary nebulae, which can be used in the manner of distance-determination of the brightest star of a galaxy, the globular cluster luminosity function, or a brightest cluster galaxy in a galaxy cluster.

Typically, observation is carried out for an [O III] forbidden line (wavelength 500.7nm), which is produced by planetary nebulae and can be observed from the ground, and established as from a planetary nebula, i.e., other possible sources eliminated. By observing a number of them in a galaxy, the distance to the galaxy can be estimated based upon the brightest of the group. The function is typically stated in a way that relates a distance modulus to the apparent magnitude of this line from the galaxy's brightest planetary nebulae.

Planetary nebulae occur throughout galaxies, including easy-to-view portions, which makes them better for this than some other such standard candle candidates within galaxies.


(nebulae,galaxies,distance)
http://en.wikipedia.org/wiki/Planetary_nebula_luminosity_function
https://ned.ipac.caltech.edu/level5/Jacoby/Jacoby8_1.html

Referenced by:
cosmic distance ladder

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