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Download Synphot User`s Guide - stsdas
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Photometry 29 The results from calcphot are shown in Figure 3.8, where we see that we can reach an H magnitude of 20.8. Figure 3.8: Calcphot Results for a NICMOS F160W Observation Mode = band(h) Pivot Equiv Gaussian Wavelength FWHM 16448.03 2040.669 band(h) Spectrum: rn(crgridbpgs$bpgs_147,band(nicmos,2,f160w),10,c ounts) VZERO VEGAMAG 0. 20.79155 The calcphot task is also useful for making photometric measurements of existing spectra, either in HST instrumental bands or standard ground-based filter systems. For example, let’s say you’d like to demonstrate for some students the importance of the 4000 Å break on the U−B colors of redshifted galaxy spectra. First, you might want to produce a plot showing the U and B bandpasses relative to some redshifted spectra. The plspec and plband commands shown in Figure 3.9 will produce the plot shown in Figure 3.10. Note that the bandpass plots are multiplied by a scale factor to place them in the same range of data values as the spectra. Figure 3.9: Commands for Plotting Redshifted Spectra and UB Bands plspec plspec plspec plspec plspec plband plband "" "z(crgridkc96$elliptical_template,0.0)" "" "z(crgridkc96$elliptical_template,0.2)" "" "z(crgridkc96$elliptical_template,0.4)" "" "z(crgridkc96$elliptical_template,0.6)" "" "z(crgridkc96$elliptical_template,0.8)" "band(u)*3.e-14" app+ ltype=dashed "band(b)*3.e-14" app+ ltype=dashed flam flam flam flam flam app+ app+ app+ app+
