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XMM-Newton Science Analysis System


esources (esources-1.2) [xmmsas_20070708_1801-7.1.0]

Meta Index / Home Page / Description

Source inclusion criteria

Criteria for inclusion of a source in the output list are as follows:

• The maximum value of the source ID number is limited by the number of characters allocated to hexadecimal source ID numbers (parameter numhexchar). The source ID number is a hexadecimal version of the SRC_NUM column.
• No source is considered for which the ii_CTS value is null for all three EPIC instruments.
• Sources are included only if a weighted sum $C$ of the ii_CTS values $c_i$ exceeds mintotalcts. The weight formula is

  
  

  $$C = \frac{\sum_{i=1}^{3} \delta_i \ c_i}{\sum_{i=1}^{3} \delta_i \ w_i}$$ (1)

  
  

  where the index $i$ runs over the three EPIC instruments, $\delta_i$ equals 0 if $c_i$ is a null value but 1 otherwise, and $w_i$ is a normalized weight associated with the instrument.

• ii_DET_ML must be $>$ mindetml and ii_MASKFRAC must be $>$ minmaskfrac for at least one of the instruments ii.
• The calculated width of the time bins must be $>0$.