RXTE Cross Calibration Status
1998 October 28
In response to a suggestion from the RXTE Users Group,
this is the first of a regular series of status reports on an
effort to quantify the quality of the PCA and HEXTE response
matrices, and to improve the cross calibration between the
two instruments. This is a joint effort of the PCA/HEXTE
teams, and we anticipate posting a progress report approximately
every two weeks.
Current activities are focussed on the PCA and HEXTE analysis of a common
dataset: public observations of the Crab made in 1997 December (ObsIDs
20804-01-05 through 20804-01-10). With
assistance from Arnold Rots, we have produced phase-resolved and
background-subtracted spectra of the Crab in the PCA and the HEXTE, and we
shall be analyzing these separately and jointly in the next few weeks.
Outstanding PCA issues
- quantifying the equivalent widths of the smallest robustly measured
spectral features, and documenting the location of known or observed
and potentially spurious features.
- quantifying the effects of the non-linearities in the assumed
xenon physics, particularly effects which are not included in the
generation of matrices for historical gas filled detectors.
- documenting the relative reliability of the response matrices for
the different detectors, including the effects of time variation
in the matrices.
Here are the 1997 December PCA total and phase resolved spectra of
the Crab nebula. As of November 3, 1998, no deadtime corrections have been
applied (the average deadtime is ~5%; variations with phase have not been accounted
for). Address questions about these data to Keith Jahoda of the PCA team.
Many PCA specific questions are addressed on the PCA page.
Outstanding HEXTE issues:
- Verifying the collimator responses by fitting scans across other sources
- Measuring the detector open areas using ground calibration data
- Improving the response matrix (RMF) by understanding the origin of
residuals observed when fitting bright-source spectra, and including
those effects in the Monte-Carlo model.
- Comparing HEXTE Crab spectral fits with those from the BeppoSAX PDS
and CGRO OSSE instruments.
The HEXTE ftp site at UCSD has the latest
HEXTE Crab reference data and response files, which are being used in
the cross-calibration effort. Please contact Philip Blanco (pblanco@ucsd.edu) if you intend to use
these for your research.
For further HEXTE-specific information please refer to the HEXTE Calibration
News WWW page (at UCSD).
Coming soon...
Results of joint PCA/HEXTE spectral fits to the phase-resolved spectra
of the Crab.
RXTE Calibration News - current released calibration files and
supported software
- Rossi X-ray Timing
Explorer:
- Proportional Counter Array
- High Energy X-ray Timing
Experiment
Last modified by K.
Jahoda
and
P. Blanco 2-Nov-98