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EXOLOG: Help

EXOLOG - EXOSAT Observation Log


Overview

This database table contains the EXOSAT observation log. This is a complete list of all EXOSAT observations, observing modes, and principal investigators. The log can be used to find out which targets were observed by EXOSAT, who observed them, and the current state of the data analysis.

References

Taylor B.G. et al., 1981 Sp. Sci. Rev., Vol. 30, p. 479.

White N.E. and Peacock A.P. 1988, X-ray Astronomy with EXOSAT,
    [eds. N.E. White and R. Pallivicini], Memoria S. A. It., p. 59.

Provenance

The HEASARC revised this database table in August, 2005, in an effort to modernize its parameter names and add Galactic coordinates.

Parameters

Name
The `name` parameter gives the target name. This name usually corresponds to the target name as specified by the original observer. If a source has been observed by different observers it may be entered under two or more names. It is recommended that any search by `name` always be followed by a search on the found coordinates.

RA
The Right Ascension of the EXOSAT pointing.

Dec
The Declination of the EXOSAT pointing.

LII
The Galactic Longitude of the EXOSAT pointing.

BII
The Galactic Latitude of the EXOSAT pointing.

Time
The `time` of the observation refers to the start time. Times are accurate to the nearest second.

End_Time
The end time of the observation. The units and use of this parameter are the same as those for `time`.

Sequence_Number
The number of the observation, in chronological order from the beginning of the mission.

Target_Number
target number

Observer
The principal investigator for the observation.

Observer_Code
observer code

Proposal_Code
proposal code

Proposal_Type
A code was assigned to each EXOSAT proposal that approximately defined the class of object to be observed. The codes are as follows:

                 AGN - active galactic nuclei
                 EXG - other kinds of galaxies
                 CLU - clusters of galaxies
                 HLX - high luminosity galactic sources
                 LLX - low luminosity galactic sources
                 SNR - supernova remnants
                 OPS - operational activities
                 CAL - calibration
                 DEE - deep field
                 MIS - miscellaneous
                 PV  - performance verification
                 TOO - target of opportunity
  

Instrument
For each observation there is one entry per instrument. The `instrument` parameter gives the name of the instrument. It can be `LE1`, `LE2`, `ME` or `GSPC`. The two LE telescopes are treated as separate instruments because the filters and other instrument modes can be different.

OBC_Modes
The OBC modes define on-board computer programs that were running during the observation. Each program has a short name, e.g., HTR3. More details about these programs can be found in the EXOSAT FOT handbook, available from the EXOSAT Observatory. The programs depend on the instrument as follows:

   LE:             O = old DIRECT
                   N = new DIRECT without spatial filter
                   D = new DIRECT with diamond filter
                   R = new DIRECT with rectangular filter

   ME:            T3 = HTR3 in full sub-mode
                  P1 = PULS (old version)
                  P2 = PULS2 (new version, with background spectrum)
                  E5 = HER5
                  EH = HER3 or HER4 (data per half array)
                  EQ = HER3 or HER4 (data per quadrant)
                  ED = HER3 or HER4 (data per detector)
                  E2 = HER2
                  D2 = MDIR2 (new direct)
                  I7 = HER7
                  T4 = HTR4
                  I6 = HER6
                  T3 = HTR3 OPT
                  T5 = HTR5

   GSPC:           0 = old DIRECT
                   N = new DIRECT
                   H = HEBL2 or HEBL4
  

Payload_Status
This is a code that gives information concerning the instrument modes for each observation. The code depends on the instrument as follows:

    LE Filters:                        LE detector:
              P = PPL                             C = CMA with filter
              4 = 4000 Lexan                      G = CMA with grating
              A = Al/Pa                           P = PSD
              3 = 3000 Lexan
              B = Boron

   The orientation of the ME array halves:
                                 1 = half 1 offset for part of the period
                                 2 = half 2 offset for part of the period
                                 C = coaligned for part of the period.

   The number, as a hexadecimal digit, of ME high voltages on. If all 16
   detectors are turned on then no character is given. (The argon and
   xenon layers are treated here as separate detectors).

   The GSPC gain used:
                    1 = gain 1.0
                    2 = gain 2.0
                    + = non standard gain, probably 0.5.
  

Channel_Compression
The number of channels combined by the OBC; e.g., 1 means full resolution, and 4 means the summing of every 4 adjacent channels.

Channel_Selection
The ME PHA channel selection and compression:

               spectra                           intensity channels
               -------                           ------------------
            0 = all channels                      A = one argon, no xenon
            1 = argon 4-67 or 5-68, no xenon      B = two argon, no xenon
            2 = argon 4-67 and xenon 138-201      C = one argon, one xenon
            3 = argon 4-67 and xenon 132-195      D = four argon (HER7)
            4 = argon 4-35 and no xenon           E = 4 ranges, with one or
            5 = argon 0-63 and no xenon                more xenon
            6 = argon 0-127 and no xenon          X = one or two xenon, no
            ? = a non standard selection               argon
  

Argon_Integration_Time
The accumulation time in seconds of the spectral data for the ME argon data.

Xenon_Integration_Time
The accumulation time in seconds of the spectral data for the ME xenon data.

Intensity_Sample_Interva
intensity sample interval, sec

FOT_Name
for archive request submission

FOT_Start
for archive request submission

FOT_End
for archive request submission

FOT_Time_1
for archive request submission

FOT_Time_2
for archive request submission

FOT_Time_3
for archive request submission

Multiple_Fot_Flag
for archive request submission

Footnotes
footnotes


Contact Person

Questions regarding the EXOLOG database table can be addressed to the HEASARC User Hotline.
If you have any problems, please consult the help page or mail ledas-help@star.le.ac.uk
 
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