Spectrum Ultimum Capellae

Capella is the strongest coronal line source accessible to Chandra. It has been cumulatively observed with gratings for over 1.2 Msec thus far. The accumulated spectrum represents astrophysical ground truth for atomic physics calculations that is unprecedented in quality. We analyze co-added spectra from ACIS-S/HETG, ACIS-S/LETG, and HRC-S/LETG to generate a comprehensive list of detectable lines and their locations, spanning two orders of magnitude in photon energy. We compare the locations of identifiable lines with locations from atomic databases ATOMDB and Chianti and characterize the uncertainties in the databases. The full line lists and comparisons will be made available at the Dataverse here.