GeminiFocus 2017 Year in Review | Page 73

Figure 13. GMMPS optionally displays a wavelength grid (yellow numbers) for each spectrum, including the wavelength interval (bright blue) cut out by the detector gaps. Second order contamination can also be shown (orange shaded area). • Slit placement area accurately measured (no more lost slits); users to perform the following tasks (among others): • Consistent visualization of band- and mi- cro-shuffling mask designs; • Overlay wavelength grids and display 2nd order contamination (Figure 13); • Spectral packing in micro-shuffling mode, allowing for much greater slit density; • Display individual wavelengths and atomic line series (optionally redshifted); • Allowing tilted slits in micro-shuffling mode (e.g., for faint strong lensing arcs); • Display the wavelength intervals cut out by the detector gaps; • Display of required Phase II parameters for the Observing Tool; • Interactively adjust the central wavelength to preserve spectral features of interest (Figure 14). • Extensive integrated help web pages, also available online here; • Simpler and more robust source code in- stallation. In addition, accurate mathematical models of both GMOS spectrographs have been inte- grated (see the GMOS WaveMapper item on next page). They pre- dict accurately (within a few pixels) where a certain wavelength will fall onto the detec- tors — as a function of slit position, cen- tral wavelength, and grating. Using these models and full opti- cal throughput curves, the length of the spec- tra and their location are accurately known in advance, allowing January 2018 / 2017 Year in Review The new version of GMMPS allows users to design the masks in a more transparent and robust manner, and provides a quantitative and accurate preview of any data obtained. Figure 14. The central wavelength (CWL) of GMOS can now be adjusted interactively, guided by the wavelength displays (see Figure 13). Optionally, individual wavelengths and atomic line series can also be shown. GeminiFocus 71