WorkOp-IV summary: lessons from iron opacities

The fourth international LTE opacity workshop and code comparison study, Wo rkOp-IV, was held in Madrid in 1997, Results of this workshop are summarize d with a focus on iron opacities. In particular, the astrophysically import ant photon absorption region between 50 and 80 eV is emphasized for a seque nce of iron plasmas at densities and temperatures that produce nearly the s ame average ionization stage(Z* similar to 8.6). Experimental data that add ressed this spectral region is also reviewed. (C) 2000 Published by Elsevie r Science Ltd. All rights reserved.