Pandeia Reference Data

Information about JWST reference data and how to find the source of the reference data from the reference data files is provided in this article.

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Types of reference data

The JWST ETC reference data folder contains a number of types of data, including:

  • Background spectra
  • Extinction spectra
  • Throughput files for JWST
  • Normalization bandpasses (except HST filters, in the Synphot data package)
  • PSF datasets, for all instrument configurations.
  • Source spectral definitions (most template and model grid spectra is in the Synphot data package)

Throughput files

The JWST throughput files are found in the Pandeia data directory at "$pandeia_refdata/jwst/". Each instrument is in its own subdirectory, along with general telescope and detector information. The origin of particular reference data can often be found in the "config.json" file within a directory. For example, in "$pandeia_refdata/jwst/miri/config.json", lines 1743–1780 show the source information as follows:

$pandeia_refdata/jwst/miri/config.json 
        "meta": {
            "author": {
                "2016-07-21": "T. E. Pickering",
                "2016-08-20": "Nicholas Earl",
                "2017-03-31": "N. Earl, B. Nickson, S. Kendrew",
                "2017-09-11": "B. Holler, S. Kendrew",
                "2017-11-15": "B. Holler, S. Kendrew",
                "2022-10-04": "B. Holler",
                "2022-10-12": "B. Holler"
            },
            "history": {
                "2016-07-21": "Create initial template from pandeia config file",
                "2016-08-20": "Initial inclusion from published results.",
                "2017-03-31": "Updated saturation limit and removed quantum yield curve from the quantum efficiencies.",
                "2017-09-11": "Added ge_ar1_trans and ge_ar2_trans.",
                "2017-11-15": "Updated filter reference files to set throughput to 0 outside of the bandpass defined in this file.",
                "2022-10-04": "Updated list of reference files, updated MRS wavelength ranges",
                "2022-10-12": "Updated list of reference files"
            },
            "litref": {
                "2016-07-21": "pandeia_data master",
                "2016-08-20": "None",
                "2017-03-31": "None",
                "2017-09-11": "None",
                "2017-11-15": "None",
                "2022-10-04": "JETC-2887, MIRI EC Report: MIR-COMM-TN-106",
                "2022-10-12": "JETC-2887, MIRI EC Report: MIR-COMM-TN-106"
            },
            "pedigree": {
                "2016-07-21": "pandeia_data master",
                "2016-08-20": "ground",
                "2017-03-31": "ground",
                "2017-09-11": "ground",
                "2017-11-15": "ground",
                "2022-10-04": "INFLIGHT",
                "2022-10-12": "INFLIGHT"
            }
        },

Spectral libraries

The spectral libraries used by Pandeia are also found in the reference data directory, inside the "$pandeia_refdata/sed" subdirectory.

General information can be found in "$pandeia_refdata/sed/config.json", while information about individual sources can be found at "$pandeia_refdata/sed/<type>/spectra.json", where "<type>" is an available spectrum type such as "brown2014" for the Brown et al. (2014) galaxy spectra. In the case of the Brown et al. galaxy spectra, the "README" file also contains useful information on the source of the spectra:

pandeia_refdata/sed/brown/README 
These data are taken from "An Atlas of Galaxy Spectral Energy
Distributions from the Ultraviolet to the Mid-Infrared" by
Brown et al. (2014) http://dx.doi.org/10.5072/03/529D3551F0117

The FITS files contain the spectra in the form of restframe wavelength
(Angstroms) and flux per unit wavelength (ergs/s/cm^2/Angstrom).  The FITS
files were generated from the original ASCII files using ../../devtools/brown2fits.py.

The 'summary.csv' file provided with the spectra was used as the basis for the JSON
config files. The script ../../devtools/brown2json.py parses summary.csv and produces
spectra_all.json.  A display key is added to each entry to toggle whether or not the galaxy
will show up in the UI.  Edits to this key are done to spectra_all.json and then ../../devtools/brown2disp.py
run to generate a trimmed catalog, spectra.json.

With the exception of the "hst_calspec" spectra, all of the actual spectrum FITS files are in the Synphot dataset, and only configuration files that map names to filenames exist in the "$pandeia_refdata" directories.


References

Brown, M. J. I. et al. 2014, ApJS, 212, 18 
An Atlas of Galaxy Spectral Energy Distributions from the Ultraviolet to the Mid-Infrared



Latest updates
  •  
    Updated for ETC 2.0

  •  
    Updated for ETC 1.6

  •  
    Updated for ETC 1.5.


  • Added references section, added reference, and fixed link in the text.


  • Updated for ETC 1.3.
Originally published