Wednesday, August 19, 2009

Solar abundances in xspec

Jeremy Sanders provided Solar abundances from Asplund, Grevesse & Sauval (2005) which I have added to abundances.dat in the develop version of xspec.

Update 9/8/09: Martin Asplund supplied values from his 2009 ARAA paper so I used them instead for the aspl abundance option.

light curves with extractor

Alex requested a way of better controlling the start time of a light curve created using extractor. I've added a new parameter lcstart which sets the time of the first bin (in spacecraft time units). This is checked into the development version as extractor v5.12.

cleansis

We have seen a few cases of observations of bright sources using Suzaku where running cleansis creates a hole in the image. Part of the problem is running with too high a log probability parameter but there is also a subtle error when iterating. Pixels which are already identified as bad and have their counts set to zero are still included when calculating the local background. This artificially lowers the estimated background hence increases the probability that a pixel will be flagged as bad.

I changed the algorithm so that pixels flagged as bad in previous iterations are ignored when calculating the local background. This change has been checked into the development version.

New release

HEAsoft 6.7 is now available. This includes XSPEC v12.5.1. The biggest change is in gain fitting which has been reworked as the preliminary step towards allowing the creation of response models. Response models will be created analogously to spectral models and will be used to either replace or augment response matrices.

This release is also the first which does not include XSPEC v11. This version has in practice not been supported for some time and it is getting increasingly difficult to ensure that it builds and runs on all systems.