SPECTRA extension

The grid of spectra appear in the last extension as a BINTABLE called SPECTRA which contains the following columns

PARAMVAL 		 mE 		 vector of interpolation parameter values for the spectrum 


where m is the number of interpolation parameters 


INTPSPEC 		 nE 		 spectrum where n is the number of energy bins 


ADDSP001 		 nE 		 spectrum contribution for 1st additional parameter 


ADDSP002 		 nE 		 spectrum contribution for 2nd additional parameter 

...  

The ADDSPnnn columns are only included as necessary (i.e. there will be NADDPARM of these columns). The spectra are ordered with the last parameter changing fastest eg if we have two parameters each of which takes three values (1,2,3) then the spectra are ordered (1,1), (1,2), (1,3), (2,1), (2,2), (2,3), (3,1), (3,2), (3,3).

If the NXFLTEXP keyword was read from the PRIMARY header then for each unique PARAMVAL there will be NXFLTEXP rows.

This extension should also include the standard OGIP keywords :

HDUCLASS 		 'OGIP'           


HDUCLAS1 		 'XSPEC TABLE MODEL'    


HDUCLAS2 		 'MODEL SPECTRA'    


HDUVERS 		 '1.0.0'          

HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public

Last modified: Monday, 18-Oct-2021 15:22:13 EDT