SAS Watchout - pps products calclosed - XMM-Newton
I do not find EPIC (or RGS or OM) processed data in my PPS distribution. Did something go wrong with the pipeline processing?
Not necessarily. There are several possibilities why your PPS selection may not contain all pipeline products:
1) The PI has asked explicitly to give all telemetry to EPIC or RGS: in this case, the PPS will contain only the requested instrument (and OM products).
2) Your PPS selection includes exposures dedicated to calibration. The PPS pipeline is by design not intended to process exposures performed using non-science modes or filters.
There are several cases of such exposures:
- A typical and rather frequent example are the EPIC closed (optical blocking filter closed) or cal-closed (CCD cameras illuminated by an internal calibration source) exposures. Such exposures in each EPIC camera are frequently taken at the beginning or the end of an XMM-Newton orbit, especially in periods of high radiation. A full orbit lasts about 48 hours. However, part of this time is not available for science due to high particle radiation background. This background component is particularly intense during and immediately before and after the crossing of the Earth's radiation belts. During the time between the first observation of a revolution and the time when the radiation model predicts a radiation level as low as to allow science observations to start without being affected by high background, closed and cal-closed observations of short duration are scheduled for EPIC. Normally, RGS and OM exposures are not set up in such observations, therefore no PPS products are processed.
- EPIC is often set up with calibration modes during dedicated RGS and OM routine calibration observations. In this case, PPS products are available for RGS and OM only.
- A similar situation occurs when dedicated EPIC calibration exposure are scheduled at the same position of a science target to save slew time, just before or after the science exposure. RGS and OM run in parallel, generally with the same instrumental configuration as the next "normal" science observation. In this case, PPS products of the science target are generated for RGS and OM.
- When the OM camera filter needs to remain closed due to the presence of a bright star in the field of view, the OM time is employed for internal calibration exposures. The PPS products are processed only for EPIC and RGS in this case.
Users are encouraged to check the instrumental configuration of a performed XMM-Newton observation in The XMM-Newton SOC Observation Database.
In rare cases it may happen that science exposures are erroneously not processed due to problems in the data format (e.g. due to telemetry problems) or in the pipeline reduction software. In case of doubts, users are always encouraged to contact the XMM-Newton HelpDesk.