Data formatΒΆ
The data file you will need to feed to the fitter should contain one source per
line. Each line should contain 3*(n+1)
columns, where n
is the number
of wavelengths/filters for which fluxes are given:
- Column
1
should contain the source name, with no spaces - Columns
2
and3
should contain the source coordinates - Columns
4
to3+n
should contain a flag for each flux, where the flag can take the following values:0
for data points which are not valid or used1
for valid data points2
for lower limits3
for upper limits4
for valid data points (as for1
) but where the fluxes and errors are expressed as and . This is useful for sources which have a magnitude with a large error, which can then be converted to and without worrying about the conversion from magnitude and magnitude error to linear fluxes and errors.
- Columns
4+n
to3*(n+1)
should contain the fluxes and flux uncertainties, alternated, in mJy. For lower and upper limits, the error should be set to the confidence placed on the limit, with 0 corresponding to 0% and 1 corresponding to 100%. For example, in the case of an upper limit, setting the confidence to 1 effectively forbids any models to be larger than the upper limit, while setting the confidence between 0 and 1 allows such models, but introduces a penalty dependent on the confidence. Setting the confidence to 0 effectively disables the upper limit.
We refer to this format as the fitter data format. Note that in a single
data file, all lines should have the same number of columns. If one or more
fluxes are not available for a specific source, the flag for these fluxes can
be set to 0
.
An example data file with four fluxes per source is shown here:
SSTGLMC_G009.8925-00.3420 9.89250 -0.34200 1 1 1 1 6.869e+01 6.869e+00 1.512e+02 1.512e+01 1.626e+02 1.626e+01 9.015e+01 9.015e+00
SSTGLMC_G009.8940-00.3367 9.89408 -0.33675 0 0 1 1 -9.999e+02 -9.999e+02 -9.999e+02 -9.999e+02 7.412e+00 7.412e-01 1.199e+01 1.199e+00
SSTGLMC_G009.8943-00.3378 9.89430 -0.33783 0 0 1 1 -9.999e+02 -9.999e+02 -9.999e+02 -9.999e+02 4.462e+00 4.462e-01 6.927e+00 6.927e-01