Kurucz Atmospheres in WDx

WD9 5 (as well as WD93K93, which has been used for light curve modeling of EBs since 1993) and the current version, WDx2 0 07, make use of Kurucz's stellar atmosphere models. The atmospheres were integrated over the standard system passbands UBVRJIJ, RCIC, and uvby, the nominal extended Johnson infrared passbands JHKLMN, the improved infrared passbands, iz, iJ, i H, iK, iL, iL', iM, iN, in, and iQ, and for a range of narrow, square-edged passbands centered on wavelengths in the far-ultraviolet, appropriate for IUE, HST, or other space platforms with far-ultraviolet detectors. The raisons d'etre and other details of infrared passband optimization may be found in Young et al. (1994).

The flux ratio files for a specified filter can be computed as described below. This procedure was developed and applied by C.R. Stagg at the University of Calgary. At first we tabulate the filter transmission function. Then create a file of wavelength versus transmission for the filter.

line 2 WLBEGIN, TRANSMISSION (WLBEGIN)

last line WLEND, TRANSMISSION (WLEND)

4 Kurucz CD-ROM No. 13 ATLA S9—Stellar Programs and 2km/s grid. Robert L. Kurucz, Aug 22, 1993, Smithsonian Astrophysical Observatory. Cambridge, MA 021138, USA. Copyright Smithsonian Astrophysical Observatory, 1993.

5 The symbol [Fe/H] denotes the logarithm of the ratio of iron and hydrogen abundances relative to the same ratio for the Sun. Thus, stars of solar composition have [Fe/H] = 0.

FACTOR is the factor to multiply the wavelengths to convert them to nm, i.e., WLBEGIN*FACTOR = WLBEGIN (nm). The wavelengths (in nm) must correspond to those in the file FPHEAD. NW is the number of wavelengths listed. All lines are in open format.

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