Correcting for the Effects of Interstellar Extinction
E. L. Fitzpatrick;
PASP, 1999, 111, 63
ABSTRACT:This paper addresses the issue of how best to correct astronomical data for the wavelength-dependent effects of Galactic interstellar
extinction.
The main general features of extinction from the IR through the UV are
reviewed, along with the nature of observed spatial variations.
The enormous
range of extinction properties found in the Galaxy, particularly in the UV
spectral region, is illustrated.
Fortunately, there are some tight
constraints on the wavelength dependence of extinction and some general
correlations between extinction curve shape and interstellar environment.
These
relationships provide some guidance for correcting data for the effects of
extinction.
Several strategies for dereddening are discussed along with estimates of the
uncertainties inherent in each method.
In the Appendix, a new derivation of the
wavelength dependence of an average Galactic extinction curve from the IR through
the UV is presented, along with a new estimate of how this extinction law
varies with the parameter R=A(V)/E(B-V).
These curves represent the true
monochromatic wavelength dependence of extinction and, as such, are suitable for
dereddening IR-UV spectrophotometric data of any resolution and can be used to
derive extinction relations for any photometry system.
KEYWORDS: ism: dust, extinction
PERSOKEY:extinction, dust, optical, uv, ,
CODE: fitzpatrick99