HEASoft and XSPEC are now available as conda packages. See details ....
Appendix J: Glossary
- Component – A part of a model.
- Additive – A component which produces a theoretical spectrum.
- Multiplicative – A component which produces multiplicative factors to apply to the current theoretical spectrum.
- Convolution – A component which modifies the current theoretical spectrum
- Mixing – If there are multiple datasets with separately calculated theoretical models this component modifies all of them simultaneously.
- Datagroup – A set of observed spectra which will all be fit using the same model and parameter values.
- Dataset – The observed spectrum and its associated information.
- Fit statistic – The statistic used to determine the best fit value. The options are based on maximizing the likelihood.
- Model – The parameterized theoretical model for the source spectrum. There is a default unnamed model but additional named models can be defined.
- Plotgroup – A set of spectra which are summed together for plotting purposes only.
- Response Model – A model which modifies the response. At the moment this is limited to the gain.
- Source – In some observations several objects can contribute to the same spectrum. In this case XSPEC refers to them as different sources and each source can have its own model and response.
- Table Model – A model component stored as a FITS file containing model spectra tabulated on a grid of parameter values.
- Test Statistic – The statistic to provide the
goodness-of-fit criterion after the parameters have been optimized
based on the fit statistic