To find and download HEASARC data in the cloud, you can use astroquery.heasarc or download our new tool, hark.
The HEASARC and NuSTAR teams are greatly saddened by the sudden passing of Katja Pottschmidt. Most recently Katja was the lead scientist for the NuSTAR Guest Observer Facility (GOF), a role she had supported for many years. During her science career she worked on many other high energy astrophysics missions and played an integral role in advancing our knowledge of the universe. She was a wonderful colleague and friend and will be keenly missed by all who knew her.
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recorn: change correction norm for a spectrum
This model is a replacement for and improvement on the old xspec command recornrm. If a correction file is in use for a spectrum then its normalization can be fitted for using this model. The first parameter, which is not variable, is the spectrum number and the second the correction file normalization. The starting value of the second parameter should be set to the current value of the correction file norm (this can be independently set using the cornorm command).
Note that in order to fit the cornorm parameter the calculation of parameter derivatives during the fit must be switched to the slower full numerical differentiation algorithm. This can be done either by
XSPEC12>xset usechainrule noor by changing the USE_CHAIN_RULE setting in the Xspec.init start-up file to false. This does slow down the fit so is not recommended for general use.
| par1 | specnum: spectrum number |
| par2 | cornorm: correction file normalization |