Synphot Data User's Guide

A.1 Introduction to all available spectral catalogs

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Both observed and synthetic spectra are available to synphot users. Table A.1 summarizes the contents, access mode, and status of the available catalogs.

The first three columns contain, respectively, the catalog reference, the type of objects, and whether the spectra are models or observed.

Column 4 provides the sample syntax for accessing these spectra: in some cases, a filename must be provided, and in others, use of the synphot function cat or icat can be used. These functions allow access by specifying model parameters (effective temperature, metallicity, log gravity); the difference between the cat() and icat() functions is that cat() selects the spectrum closest matching the specified parameters while icat() interpolates between models that bracket the specified parameters.

The icat task can give incorrect results without warning if it is used at the edges of the defined grid of models. See the relevant section below for the available ranges for each atlas, and exercise caution when selecting a value near one of the extremes.

Column 5 indicates whether the catalog is recommended or deprecated, with an alternative recommended in the case of deprecated catalogs. A blank entry in this column indicates that there may be more recent catalogs available in the literature which have not been incorporated into the synphot catalog set. Deprecated catalogs remain available to guarantee work continuity and to make comparison checks between older and newer spectra available.

Table A.1: Summary of all Spectra Available in Synphot and Related Information. See text for details.

Spectra Set	Object Type	Model or Observed	Access	Status
HST Calibration Spectra	Stars	Observed	crcalspec$zzzzzz_nnn.fits	Recommended
Castelli and Kurucz 2003, 2004	Stars	Model	icat(ck04models,t,m,g)	Recommended
Pickles 1998	Stars	Observed	crgrid$pickles/dat_uvi/pickles_nnnn.fits (or dat_uvk)	Recommended
Kinney and Calzetti	Galaxies	Observed	crgridkc96$xxxx_template.fits
AGN atlas	AGNs	Observed	crgridagn$xxxx_template.fits
Galactic Atlas	Various	Observed	crgridgalactic$zzzz_template.fits
Kurucz 1993	Stars	Model	icat(k93models, t,m,g)	Deprecated/ Use Castelli and Kurucz instead
Bruzual 1977	Stars	Model	crgridbz77$bz_nn.fits	Deprecated/ Use Pickles 1998 instead
Gunn and Stryker 1983	Stars	Observed	crgridgs$gs_nn.fits	Deprecated/ Use Pickles 1998 instead
Bruzual et al 1979-1983	Stars	Observed	crgridbz77$bz_nn.fits	Deprecated/ Use Pickles 1998 instead
Jacoby, Hunter and Christian 1984	Stars	Observed	crgridjac$jc_nn.fits	Deprecated/ Use Pickles 1998 instead
Buser and Kurucz 1979	Stars	Model	crgridbk$bk_?nnnn.fits , where ? is one of (a,b,c,d,m,s)	Deprecated/ Use Pickles 1998 instead
Bruzual and Charlot 1995	Galaxies	Model	crgridbc95$templates/bc95_x_XXXX.fits	Deprecated/ Use GISSEL and Starburst99