PHA keywords
The PHA file standard includes several keywords that are used to store information about the instrument response associated with the spectrum. If these keywords are defined then the fitting engine - such as Sherpa, ISIS, or X-Spec - will automatically load in the response files for you.
The relevant keywords are:
| Keyword | Description |
|---|---|
| ANCRFILE | Used to store the name of the ARF for the source. |
| BACKFILE | Used to store the name of the PHA file containing the background for the source. |
| RESPFILE | Used to store the name of the RMF for the source. |
These keywords are set for you if you use a CIAO script, such as specextract, but can also be set manually by using the dmhedit tool or the header-editing capabilities of prism. They can also be listed by:
unix% dmlist src.pi header | grep FILE 0100 BACKFILE bgnd.pi String 0101 CORRFILE none String 0102 RESPFILE src.rmf String 0103 ANCRFILE src.arf String
or
unix% dmkeypar src.pi ancrfile echo+ src.arf
