The XSPEC projct model is used to estimate parameters in 3-D space from the 2-D projected spectra. It is used as follows.

Suppose you have a Chandra observation of a cluster of galaxies and you extract three spectra file1.sp, file2.sp, and file3.sp from concentric annuli of width 20 arcsec ie the file1.sp is from the center to a radius of 20', file2.sp is from 20' to 40', and file3.sp is from 40' to 60'. For simplicity we will assume that these are all circular annuli. The first step required is to add some keywords to each of the files.

projct model (last edited 2008-01-30 13:45:22 by KeithArnaud)