The new user will need to first read Chapter 14 on how to obtain a copy of XSTAR, and is then advised to read Chapter 2 which gives the flavor of an XSTAR session, and provide sufficient information to get started. The chapters 3 and 4, give an overview of the code structure and describe the input commands. The output is described in Chapter 5. More experienced users may wish to read Appendix 9, which discusses the physical assumptions made in XSTAR, or Appendix 10, on the code structure.
We emphasize here and throughout this document that XSTAR version 2 represents an almost complete rewrite of version 1. This affects not only the internal operation of the code and the numerical results, but also the user interface. These changes were motivated primarily by the desire for a more streamlined operation, and for flexibility incorporating future and current improvements in atomic data. In addition, we have tried to learn from experience gained from version 1 by eliminating options which were seldom used in favor of clearer and more straightforward specification of input parameters, and we have replaced the code which parsed the input commands and which did not function as required in some situations. In order to do so we have borrowed heavily from the well developed input and output code, and installation scripts, which have been developed in this laboratory for the FTOOLS software package. This includes the use of FITS files for some output, As a consequence, it will be necessary for even experienced users of version 1 to become familiar with the new interface.