Spectral Analysis

The x-ray spectral analysis consists of a comparison between the observed pulse height spectrum and a pulse height spectrum calculated using a given spectral model. The model, chosen by the user, is convolved with the instrument and telescope responses.

To obtain the spectral parameters for an x-ray source, several steps need to be followed. For each source:

• extract counts (pulse height spectrum) from the source or region of interest
• select background region and extract counts
• obtain the distribution of the gain values - for Einstein IPC only
• obtain the best fit parameters for a spectral model - repeated for each model of interest
• obtain a 1-D or 2-D grid of $\chi ^{2}$ values around the best fit values - this can be done for as many models as desired
• determine the flux and luminosity of the source from the best fit model

Plots of the gain distribution, the pulse height distribution, the data compared to the model spectra, and of the $\chi ^{2}$ grids can be generated.