XMM-Newton Science Analysis System
lccorr (lccorr-2.2.8) [xmmsas_20040318_1831-6.0.0]
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What you need to get started:
- A Calibration Constituents File or CCF (pointed to by SAS_CCF). This is needed because the CCF contains all the details about the telescope needed to correct for events lost (exposure).
- An EPIC event list. This is mainly needed for the timing and bad pixel information contained in the EXPOSUnn, STDGTInn, OFFSETS and BADPIXnn extensions.
- A time series or light curve compiled from that event list. In addition to the data itself, this should contain a Data SubSpace (DSS). The DSS contains information about the selection of events used to make up the time series.
- The task needs to know the position of the source in order to account correctly for any part of the point spread function (PSF) chopped off by the edge of a spatial extraction region. If you set srcposstyle=`dss', lccorr
will try to guess the source location from the information stored in the DSS. But the algorithm which has this job is not very clever. It is best if possible to inform the task about the source location by setting srcposstyle=`user' (note that this is the default for this parameter) and then supplying the source coordinates directly via parameters srcra and srcdec. The latter are angle-style params: their syntax can be found in the documentation of the param interface.
About the simplest possible call to lccorr
is therefore as follows:
setenv SAS_CCF <name of CCF file>
lccorr eventset=<evlist name> srctsset=<src ts name> srcra=<ra of src>
srcdec=<dec of src>
XMM-Newton SOC/SSC -- 2004-03-18