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epevents (epevents-6.47.1) [xmmsas_20131209_1901-13.5.0]

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Pattern related information

The following table may serve as a quick reference to select certain pattern types of recognized events (i.e. away from CCD edges, bad pixels etc.):

PATTERN Meaning
0 singles
1 doubles in Y with Y(main)$<$Y(secondary)
2 doubles in X with X(main)$<$X(secondary)
3 doubles in Y with Y(main)$>$Y(secondary)
4 doubles in X with X(main)$>$X(secondary)
5-8 triples
9-12 quadruples
128 singles at CCD window (RAWX=1, RAWX=64, RAWY=200)
  or close to bad pixels
205 doubles at CCD window or bad pixels
206 triples at CCD window or bad pixels
207 quadruples at CCD window or bad pixels

Note: as of version 6.30.4 PATTERN values of 128 have been changed to 0 (i.e. $8^{\rm th}$ bit is not set anymore for singles), and PATTERN values of 205 have been changed to 1-4 (i.e. $7^{\rm th}$ and $8^{\rm th}$ bit are not set anymore for doubles)!

Secondary events of those valid doubles, triples, and quadruples ( $\index{Columns!PATTERN}{\tt PATTERN}=1..12$) have ${\rm PATTERN(main)} + 64$ (as listed above), i.e. $7^{\rm th}$ bit set.

  1. For the pattern codes in PAT_ID and PATTERN the following bit-wise storing is used:

    PAT_ID
    bit value Meaning
    16 32768 free for additional pattern related flag
    15 16384 - " -
    14 8192 - " -
    13 4096 PAT_ORI first digit (x-coordinate)
    12 2048 - " -
    11 1024 PAT_ORI second digit (y-coordinate)
    10 512 - " -
    9 256 PAT_IND: $1,...,< 512$ (telemetry limit)
    ... ... - " -
    1 1 - " -

    PATTERN
    bit value Meaning
    8 128 sign of PAT_TYP
    7 64 sign of PAT_IND
    6 32   used to flag PAT_TYP $>4$
    5 16   if bit 6, then use next 5 bits
    4 8 MOS code numbers 0 - 12 to store PAT_TYP - 5
    3 4 a combination of hence, max storage: PAT_TYP = 36
    2 2 PAT_TYP $\le4$ and - " -
    1 1 PAT_ORI - " -

    Note: as of version 6.30.4 PATTERN values of 128 have been changed to 0 (i.e. $8^{\rm th}$ bit is not set anymore for singles), and PATTERN values of 205 have been changed to 1-4 (i.e. $7^{\rm th}$ and $8^{\rm th}$ bit are not set anymore for doubles)!

  2. Creation of event quality flags in column FLAG. epevents makes use of the common MOS/pn event related flag code (see [3]) and uses the following bits (other flags are set by the epframes task):

    FLAG
    bit value Meaning (information)
    1 0x2 INVALID_PATTERN
    2 0x4 CLOSE_TO_CCD_WINDOW
    5 0x20 CLOSE_TO_ONBOARD_BADPIX
    6 0x40 CLOSE_TO_BRIGHTPIX (not on-board)
    8 0x100 CLOSE_TO_DEADPIX (not on-board)
    16 0x10000 OUT_OF_FOV

    bit value Meaning (rejection)
    19 0x80000 COSMIC_RAY
    21 0x200000 ON_BADPIX
    22 0x400000 SECONDARY
    23 0x800000 TRAILING
    total 0xfa0000 EPN rejection mask


Files and columns Output Files Details about the pattern Home Index

XMM-Newton SOC/SSC -- 2013-12-09