Patch to replace AtomDB 2.0 with 2.0.1 in xspec

We have updated the current HEAsoft release downloads to replace AtomDB 2.0 with AtomDB 2.0.1 following the discovery of an error in the 2.0 RRC data. If you have already downloaded HEAsoft 6.11 (containing XSPEC 12.7.0) you can either get the fix from the HEAsoft issues page (http://heasarcdev.gsfc.nasa.gov/lheasoft/issues.html) or patch 12.7.0e from the XSPEC bugs page (http://xspec.gsfc.nasa.gov/docs/xanadu/xspec/bugs.html).

AtomDB v2.0 support added to xspec in v12.7

The new release of xspec uses AtomDB 2.0 for the various apec models. Since AtomDB 2.0 includes all elements to Zn there are a couple of issues to note.

1. New models vvapec and bvvapec allow all AtomDB 2.o elements to be varied independently.

2. By default the apec, bapec, vapec and bvapec models set to Solar the abundances of the elements included in AtomDB 2.0 but not in earlier versions (we refer to these as the trace elements). To set these abundances to zero use "xset APEC_TRACE_ABUND 0.0". The trace element abundances can be set to any value or linked to the abundance of one of the more common elements e.g. "xset APEC_TRACE_ABUND Fe".

xspec v12.7 released

The latest xspec release is now available through the HEAsoft download page.

The major new feature is the beta release of the Python xspec module. This is built and installed automatically on most platforms if the source code distribution is downloaded. PyXspec is not intended as a replacement for the current user interface but provides an alternative method for scripting xspec.

To learn more see the PyXspec users' manual.