HRC Calibration Review, '01
OVERVIEW
COUNT RATE LINEARITY
BACKGROUND
- Initial analysis performed during first epoch of observations
(pre-gain adjustment)
- Raw Count Rates for I of 1.5E-5 cts/s/arcsec**2
- For I: Filtering reduces this to just below ~0.9E-5
cts/s/arcsec**2
- For S: Partial Filtering gives rates of 7.5E-5 cts/s/arcsec**2;
Issue of what filtering should be done
- Relative uniformity (10% peak to trough variation)
- Good stability in spatial structure
- Initial AR Lac scans 10/99 (for Postscript)
- Lockman Hole: 90 ksec 12/99 and 100 ksec 3/00 respectively (for Postscript)
- Some decline in overall rate (for Postscript)
- Link
to relevant section on Cal web pages.
PHA/GAIN RESPONSE
TIMING PERFORMANCE
- Wiring Error matches timing information with spatial information
of the next detected event
- Turning off on-board event rejection mitigates problem (allows
reallignment of spatial and temporal data)
- HRC-I total event rate can saturate telemetry (184 ct/s)
- Switch to HRC-S with outer wings ``turned-off''
- Link
to relevant section on Cal web pages.
OUT-OF-BAND (VISIBLE/UV) RESPONSE
ON-AXIS QE MODEL
QE UNIFORMITY
- Uniformity measured at 8 energy bands post-XRCF (for
Postscript)
- Two energy bands unuseable due to bad data
- Map of smoothed median instrument response at 6 energies (for Postscript)
- We have detected a very low energy off-axis discrepancy with HRC-I/LETG
observations of HZ 43 not present in higher energy extended objects
such as the Coma Cluster
- Link
to relevant section on Cal web pages.
FILTERING
DEGAP MAP
REMAINING ISSUES AND FUTURE DIRECTIONS
- Current
Status Page
- Degap Maps: Assessment of new map for S
- QE Uniformity Maps: Low (<0.277 keV) energy non-uniformities
- MCP Quantum Efficiency
- Point-Spread Function
Contributors:
HRC IPI Team
CXC Calibration Team
Comments to cxccal@cfa.harvard.edu
Last modified: 06/24/02