Frequently Asked Questions

(1) Can I use GalFish if I am planning spectroscopic observations?

Not really. GalFish is optimized for photometric surveys.

(2) What about redshift?

We plan to include redshift as a parameter soon; the user will be able to include a Gaussian prior on the redshift measurement, reflecting the expected uncertainty on this parameter, and evaluate its impact on the forecasted errors on the other SED fitting parameters.

(3) What is the additional systematic errors box?

This error is meant to represent any additional source of error, for example calibration zero-point errors, not included in the photometric uncertainty specified as a limiting magnitude.

(4) I would like to use a filter that is not among those on the webpage. What do I do?

You are welcome to contact us at and we will do our best to make it available.

(5) I would like to study galaxies that are significantly different from the ones available on the webpage. What do I do?

The most general version of the GalFish code is in Fortran and gives the user complete freedom to choose the properties of the target galaxies. Please contact us at if you would like to receive the source code.