A dedicated address in desispec for the list of the isolated lines for arc processing

Currently, QL uses lists of arc-lines for more than one QA algorithm. When running on arc lamps spectra, we calculate the X and 'W' (Y) sigmas of arc lines from the 2D preproc image. We also use these lines to fit lines of the 1D spectra to obtain Wsigmas and fit those to a polynomial to extract the Wsigma dependence on wavelength for each fiber. In these cases, we use a shortened list of 4-5 lines that were taken from simulation and compared to the DESI line lists in files such as goodlines_ascii.txt (please put the right file name here) that have been by bootcalib. In order for QuickLook to be 'quick', we have kept the number of lines low.

As work goes forward, it would better if we did not maintain our own line list, but instead could use a standard DESI line list used by other desispec software, perhaps like goodlines_asci.txt. However, in that case we would benefit from a field that marked well-isolated and bright lines, so that QL could filter on that to obtain the handful of best lines to rely on. Is this consistent with anticipated development in the offline pipeline or simulation areas? Where will such standard files reside?

Start by locating QuickLook's current arc-line list and the referenced goodlines_ascii.txt or similarly named DESI line-list files, then review how bootcalib and related offline or simulation code use them. Determine where a shared line-list address and isolation/brightness information would belong; done means the ownership and standard source are agreed and the required metadata is available for QuickLook.

Written by the indexing model from the issue text.