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Knowledgebase: IRAC
How important is the photometric color correction for my data?
Posted by Seppo Laine on 29 January 2009 02:15 PM
Absolute calibration assumes source spectrum F(ν) is proportional to ν-1. For any other source spectrum, a color correction must be applied. Corrections are typically a few percent for stellar and blackbody sources. Corrections can be more significant for sources with ISM-like source spectra (50%–250%, depending on spectrum and passband). Please note that the measured flux density is flux density at the effective wavelength of an array: 3.550, 4.493, 5.731 and 7.872 microns, for channels 1–4 respectively.