Difference: HipeWhatsNew10x (51 vs. 52)

Revision 522013-01-21 - ChristopheJean

Line: 1 to 1
 
META TOPICPARENT name="HipeWhatsNew"
<-- ANALYTICS CODE - DO NOT EDIT -->
<-- Google Analytics script BEGIN -->
<-- Google Analytics script END -->
Line: 278 to 278
 
  • There is no change in the PACS photometer calibration since Hipe 9 and version 41 of the calibration tree.

Spectroscopy

Changed:
<
<
  • In order to be less sensitive to (on average) mispointed flux calibration observations, the flux calibration scheme has changed: the construction of the calibration tables is now based on the standard calibrators fluxes coming from the central 9 spaxels instead of the central one only. This implies that two new calibration tables were introduced in the calibration tree, namely observedResponse3x3 and calSourceFlux3x3. Those tables are used by default in specDiffCs and should lead to more reliable fluxes, notably in case of mispointed observations. An optional parameter, use3x3 (True by default), was added to specDiffCs. You can still use the former calibration scheme by setting use3x3 to False although it is not recommended.
>
>
  • In order to be less sensitive to (on average) mispointed flux calibration observations, the flux calibration scheme has changed: the construction of the calibration tables is now based on the standard calibrators fluxes coming from the central 9 spaxels instead of the central one only. This implies that two new calibration tables were introduced in the calibration tree (version 45 or higher required), namely observedResponse3x3 and calSourceFlux3x3. Those tables are used by default in specDiffCs and should lead to more reliable fluxes, notably in case of mispointed observations. An optional parameter, use3x3 (True by default), was added to specDiffCs. You can still use the former calibration scheme by setting use3x3 to False although it is not recommended.
 
  • As a result of the new calibration scheme, the absolute fluxes found at level 2 are slightly reduced.
    • For extended sources, the new calibration is more accurate
    • The new calibration should not impact point sources, thanks to the so-called "central to 3x3" correction performed in extractCentralSpectrum. That correction was not necessary in hipe 9.0, as it was implicitly contained in the flux calibration files. In hipe 10, by default no average mis-pointing is included in the calibration files anymore, hence this extra correction, making use of the flux distribution between the spaxels to estimate the mispointing and correct for it.
 
This site is powered by the TWiki collaboration platform Powered by Perl