April 12 - 13, 2006

1
XSPEC news

• Keith Arnaud

2
Release history

• v12.2.0 was released in April 2005 as part of
  HEAsoft 6.0. It was updated to v12.2.1 as part of
  HEAsoft 6.0.4 in November 2005. v12 runs on all
  HEAsoft supported systems except OSF.
• We also included v11.3.2. Our policy on v11 is
  we will continue to fix critical bugs but will
  not add new features. New models are only added
  to v12.

3
v12 features

• A spectrum can be fit by a model of form M1R1
  M2R2
• Arbitrarily complex combinations of model
  components are allowed.
• Parameters can be linked to polynomial functions
  of other parameters.
• Memory is used more efficiently and in many cases
  execution is faster.
• Type II (multi-spectrum) files are fully
  supported.
• Adding local models is much easier. Models can be
  written in Fortran (single or double precision),
  C, or C.
• Help works either through local PDF files or web
  pages.
• A summary of the differences between v11 and v12
  can be found at http//xspec.gsfc.nasa.gov/docs/xa
  nadu/xspec/xspec12/compatibility/xspec11/xspec11.h
  tml

4
in the next release

• energies command specifies energy grid on which
  the model is calculated. This is a replacement
  and enhancement of the v11 extend command.
• Improved flexibility for models of form M1R1
  M2R2

on my wishlist

• improved Bayesian/MCMC capabilities and better
  integration with other aspects of the program.
• web-based, cross-referenced model documentation
  to guide users towards appropriate models for
  classes of objects and physical processes.

5
where else should we put effort ?

• scripting options in addition to Tcl/Tk - perhaps
  Python or S-lang ?
• more models - which physical processes and/or
  astronomical objects ?
• better support for spatial-spectral and
  temporal-spectral modelling ?
• cooperating (or competing) with Sherpa and/or
  ISIS ?
• parallelization ?