This tool calculates the expected counts and signal to noise for a point source using the DEIMOS spectrograph. Currently, the user can select two gratings, the 600 and the 900, at a fixed number of tilts. For the 1200 line gratings, the throughput is averaged over all tilts to provide a single curve for the spectrometer. Values outside of those tabulated are extrapolated. The throughput measurements come from the data on the DEIMOS web pages at Keck Observatory
The input spectrum is one of the templates normalized by the specified AB or Vega magnitude in the specified filter. A flat template means that the flux is distributed as either flat in frequency or the spectrum of Vega. The total flux of the object specified by the user will be reduced to account for slit losses based on the specified slit width, height, and seeing. The target is assumed to be a point source with a PSF FWHM as specified by the seeing parameter. For DEIMOS the slit is assumed to be 10 arcseconds in length.
The output data are given in units of per pixel.
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