Stellar Content of Galaxies

Stellar Content of Galaxies - Stellar Content of Galaxies...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Stellar Content of Galaxies Decomposing the contents of a galaxy from observed properties, when we can't resolve individual stars, falls under the general heading of spectral synthesis . The galaxy luminosity as we measure it at some (emitted) wavelength λ may be written as a sum of components i which have intrinsic luminosity density ρ (r) L i ; we would like to know the total luminosity of this component (integrating ρ dV) for the galaxy, from which masses, stellar evolutionary conditions, and something about the galaxy history may be derived. The galaxy's total luminosity may be written (where r is a vector position); which expression is, like the equation of radiative transfer, complete but practically useless. Observations at many wavelengths can constrain, if not specify, the densities ρ i if they have distinguishable L i ( λ ) - that is to say, if their spectra are "different enough". The kinds of components we are interested in include: Stars: main-sequence, giant, supergiant, horizontal-branch, all as functions of spectral type or
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 2

Stellar Content of Galaxies - Stellar Content of Galaxies...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online