VI/43 EXOSAT Observation Log (EXOSAT Obs 1987; Sternberg+ 1986)
EXOSAT Observation Log
EXOSAT Observatory
<ESTEC, Noordwijk, final version (1987)>
Sternberg J.R., White N.E., Barr P., Osborne L.
ADC_Keywords: Observatory log - 440; X-ray sources - 985
Mission_Name: EXOSAT
Description:
The EXOSAT Observation Log lists archival information on 2108 pointed
observations made with the EXOSAT between May 1983 and April 1986.
Data listed include start and stop times, instrumental pointings,
object names, proposal identifications, principal investigator codes,
and observing instruments and modes of observation. The log is
intended as a reference to the data collected during the EXOSAT
mission and provides the summary information necessary to determine
what observations, if any, may be of interest in an investigation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
data.dat 136 2108 Data
pinames.dat 30 247 P.I. (Principal Investigators) Names
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See also:
J/A+AS/134/287 : EXMS catalog (Reynolds+ 1999)
Byte-by-byte Description of file: data.dat
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Bytes Format Units Label Explanations
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1- 2 I2 yr Stime.Y Start time, year, (UTC) of stable pointing
3- 5 I3 d Stime.D Start time, day
6- 7 I2 h Stime.h Start time, hour
8- 9 I2 min Stime.m Start time, minute
11- 12 I2 yr Etime.Y End time, year, (UTC) of stable pointing
13- 15 I3 d Etime.D End time, day
16- 17 I2 h Etime.h End time, hour
18- 19 I2 min Etime.m End time, minute
20- 22 I3 h RAh *Right Ascension hours (1950)
23- 24 I2 min RAm *Right Ascension minutes (1950)
25- 26 I2 s RAs *Right Ascension seconds (1950)
27 A1 --- DE- *Declination, sign (1950)
28- 29 I2 deg DEd *Declination, degrees (1950)
30- 33 F4.1 arcmin DEm *Declination, minutes (1950)
35- 51 A17 --- Tname Target name
52 A1 --- Tflag *Trim indicator
54- 61 A8 --- Prop *Proposal
63- 64 I2 --- note1 *? Footnote 1
65- 66 I2 --- note2 *? Footnote 2
67- 68 I2 --- note3 *? Footnote 3
69- 70 I2 --- note4 *? Footnote 4
72 A1 --- Cflag *Continuation flag
73- 75 I3 --- PInum *P.I. number, explained in file pinames.dat
76- 79 A4 --- Fflag *FOT flags
80- 82 I3 --- OrbNum Orbit number
84 A1 --- L1flag1 *LE1 on/off flag
85- 89 A5 --- L1flag2 *LE1 CMA filters
90- 92 A3 --- L1flag3 *LE1 config. flags
94 A1 --- L2flag1 *LE2 on/off flag
95- 99 A5 --- L2flag2 *LE2 CMA filters
100-101 A2 --- L2flag3 *LE2 config. flags
103 A1 --- Mflag *ME on/off flag
104-106 A3 --- Mpos *ME position monitors
107 A1 --- Mstatus *ME status
109 A1 --- GSflag *GS on/off flag
110 I1 --- GSgain *? GS gain
112-113 A2 --- LpMode *LE prim. OBC modes
114-115 A2 --- MpMode *ME prim. OBC mode
116-117 A2 --- MsMode *ME sec. OBC mode
118-119 I2 --- Artime *? ME Ar int. time
120-121 I2 --- Xetime *? ME Xe int. time
122-123 I2 --- ChanC *? ME channel comp.
124-125 A2 --- ChanS *ME channel selection
126-128 I3 --- Mint *? ME int. sam. interval
129-131 I3 --- GSint *? GS int. sam. interval
132 A1 --- GSprog *GS OBC program
133-134 I2 s GShint *? GS E hist. int. time
135-136 I2 --- GSrate *? GS E sample rate
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Note on RAh, RAm, RAs, DE-, DEd, DEm:
Equatorial coord. Coordinates of the star tracker, epoch 1950.0. These are
not the coordinates of the target object. The target is generally offset
from the tracker coordinates by "up to a few arc minutes."
Note on Tflag:
Trim indicator " + " if a trim maneuver preceded this period of observation
Note on Prop:
Proposal - Eight-character code indicating the class and identification of
the proposal. The following codes indicate proposal class:
AGN Active galactic nuclei
EXG Other kinds of galaxies. During the latter part of the mission
"AGN" was used to refer to these objects as well.
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
The identification of the specific proposal follows the class.
Note on note1, note2, note3, note4:
Footnotes - Two-digit codes indicating miscellaneous information about
the observation. The following codes are used:
11 Solar aspect angle < 90 deg.
12 Slight attitude instability (for part of pointing).
13 Partial telemetry loss due to ground segment or FOT production
problem.
14 Solar flare affects data.
15 ME HTR3 OPT or HTR5 running in addition to two other active
OBC programs.
16 ME/HTR3 OPT data present at 64 Hz while sampling at only 32 Hz
(so that T3 records have non-standard layout).
17 Unexplained anomaly in ME/HTR3 data.
18 ME/HER4 data partly lost/corrupted.
19 OBC data anomaly or crash for short period during observation.
21 Observation is a raster scan.
22 Observation is an occultation.
23 ME VHR used for at least part of observation.
24 le1 HER3 used for part of pointing.
27 ME PULS or PULS2 active for part of an observation, although not
the predominant configuration.
28 GS DIRECT used for part of observation although not the predominant mode
29 ME data for this observation are split between two principal
investigators (P. I.s). Between 85 264 0010 and 0820 the P. I. is
W. Brinkman (number 96).
30 Unstable pointing or scanning.
31 Coordinated observation. Sternberg et al. note the following:
Many EXOSAT observations were scheduled to be coordinated (either
simultaneously or contemporaneously) with observations from
other facilities - ground based (radio, IR, optical), airborne
(Balloon platforms, Kuiper airborne observatory) and space-based
(IRAS, IUE, Voyager, Tenma). Where this note is indicated means
that the observatory was notified of planned coordinated
observations before they were performed. It is not always known
whether individual coordinated observations using other facilities
were in fact successful. Those interested should contact the PI
directly.
32 Data contained on the FOTs may not correspond to the intended source.
Note on Cflag:
Continuation flag. Single-character code indicating whether the data
described in this record are on the same FOT as the data described in the
preceding record. Multiple records per FOT can occur either because
observation of a single target was split by trim maneuvers, or because
observations of two or more different targets have been combined onto one
FOT. Three codes are used:
* This record is the first pointing for an FOT containing multiple
targets or trims.
C This record is continues the pointings for an FOT containing
multiple targets or trims.
blank The FOT contains only one pointing.
Note on PInum:
Principal investigator. Three-digit code number indicating the name of the
principal investigator. The names and corresponding code numbers are listed
in the second file. A value of 0 in this field indicates no P. I. (as in the
case of a test, calibration, or observation of a target of opportunity).
Note on Fflag:
FOT flags. Four single-character flags indicating which FOTs exist. A blank
flag indicates there is no FOT for the corresponding instrument:
LE1 "L" if an FOT exists for the LE1
LE2 "K" if an FOT exists for the LE2
ME "M" if an FOT exists for the ME
GS "G" if an FOT exists for the GSPC
Note on L1flag1:
LE1 on/off flag. Single-character code indicating the state of the LE1
during the observation. The following characters are used:
+ The instrument was on for at least part of the pointing.
- The instrument was off or produced no useful data for the entire
pointing.
blank This information is not yet available. This value may be interpreted
as for "-", above.
Note on L1flag2, L2flag2:
LE1 and LE2 CMA filters. Five single-character codes indicating which
filters were used during the channel multiplier array (CMA) observations.
The characters representing each filter used are listed below; a blank field
indicates the corresponding filter was not used:
PPL P
4000 Lexan 4
Al/Pa A
3000 Lexan 3
Boron B
Note on L1flag3, L2flag3:
LE1 and LE2 config. flags. Three single-character codes indicating the
LE1 detector configuration. A blank field indicated the corresponding item
was not used.
CMA "C" indicates that the CMA was used with one or more filters
for at least part of the observation.
Grating "G" indicates that the CMA was used with a grating for at least
part of the observation.
PSD "P" indicates that the position-sensitive proportional counter
(PSD) was used for at least part of the observation
Note on L2flag1:
LE2 on/off flag. Single-character code indicating the state of the LE2
during the observation. The following characters are used:
+ The instrument was on for at least part of the pointing.
- The instrument was off or produced no useful data for the entire
pointing.
blank This information is not yet available. This value may be interpreted
as for "-", above.
Note on Mflag:
ME on/off flag. Single-character code indicating whether the ME was on
during the observation. Three codes are used:
+ The instrument was on for at least part of the pointing.
- The instrument was off or produced no useful data for the entire
pointing.
blank This information is not yet available. This value may be interpreted
as for "-", above.
Note on Mpos:
ME position monitors. Three single-character codes indicating the
positions of the ME halves during the observation:
Half 1 "1" if half 1 was offset for at least part of the
observation
Half 2 "2" if half 2 was offset for at least part of the
observation
Coalignment "C" if the two halves were coaligned for more than 15
minutes at a time. The 15-minute constraint excludes
those periods during array swaps when the two halves
were also coaligned.
Note on Mstatus:
ME status. Single hexadecimal digit (0 - F) indicating the number of HTs on.
This field is blank in the nominal case when all 16 HTs were on.
Note on GSflag:
GS on/off flag. Single-character code indicating the status of this
instrument during the observation.
+ The instrument was on for at least part of the pointing.
- The instrument was off or produced no useful data for the entire
pointing.
blank This information is not yet available. This value may be interpreted
as for "-", above.
Note on GSgain:
GS gain. Single-digit integer indicating which gain setting (1 or 2) was on
longest during this observation. The field is left blank if any other unusual
gain setting was used.
Note on LpMode:
LE prim. OBC mode Single-character code indicating the primary mode of
operation of the OBC during the observation:
For the LE experiments, the sub-modes comb1, COMB2, and HSRl are the only
ones of significance here; other sub-modes or programs were hardly ever
used. Distinction is made, however, between the old and new versions of the
DIRECT program, because of the more efficient use of telemetry capacity with
the latter, especially when used with a spatial filter to select events on
board.
The following codes are used to indicate the sub-mode used:
O Old version of the DIRECT program
N New version of the DIRECT program without a spatial filter
D New version of the DIRECT program with a diamond filter
R New version of the DIRECT program with a rectangular filter
Note on MpMode:
ME prim. OBC mode. Two-character code representing the "primary" OBC program
(usually the one generating the energy spectra). The following codes
correspond to the indicated programs:
T3 HTR3 in "full" sub-mode (not OPT)
P1 PULS (old version)
P2 PULS2 (new version, with background)
E5 HER5
EH HER3 or HER4 with data per array half
EQ HER3 or HER4 with data per quadrant
ED HER3 or HER4 with data per detector
E2 HER2
D2 MDIR2 (new DIRECT)
I7 HER7
T4 HTR4
Note on MsMode:
ME sec. OBC mode. Two-character code identifying a program running together
with the primary program in bytes 114-115. The same codes are used here
as in bytes 114-115 for those primary programs that were run in secondary
mode. In addition, the following codes indicate those programs that ran
only in secondary mode:
I6 HER6
T3 HTR3 OPT
T5 HTR5
Note on Artime:
ME Ar int. time. Argon histogram integration time for the primary mode, in
units of 0.1 second
Note on Xetime:
ME Xe int. time. Xenon histogram integration time for the primary mode, in
units of 0.1 second
Note on ChanC:
ME channel comp. ME channel compression, "the number of channels combined
on board into a single telemetered number, so for example '1' means full
resolution"
Note on ChanS:
ME channel selection. Two single-character codes. The first, in byte 124,
refers to the energy spectral mode and contains one of the following
characters:
O No selection (all channels sent to ground)
1 Channels 4-67 or 5-68 and no xenon
2 Channels 4-67 (Ar) and 138-201 (Xe)
3 Channels 4-67 (Ar) and 132-195 (Xe)
4 Channels 4-35 (Ar) and no xenon
5 Channels 0-63 (Ar) and no xenon
6 Channels 0-127 (Ar) and no xenon
? Any other unusual selection
The second code, in byte 125, indicates the intensity pro∼le mode:
A One contiguous range of argon channels and no xenon
B Two argon ranges and no xenon
C One argon and one xenon range
D Four ranges of argon (HER7)
E Four ranges, with at least one of them xenon
X One or two xenon ranges, and no argon
Note on Mint:
ME int. sam. interval. Intensity sample interval for the ME intensity
mode(s), if any, in milliseconds. A value of 999 is used to indicate a time
of 1 second or longer.
Note on GSint:
GS int. sam. interval. Intensity sample interval for the GSPC intensity
mode(s), if any, in milliseconds. A value of 999 is used to indicate a time
of one second bytes
Note on GSprog:
GS OBC program Single-character code indicating the OBC mode for GSPC
observations:
N new DIRECT (energy + invalid sample counter)
H Energy histogram (HEBL2/HEBL4)
O Old DIRECT (any sub-mode other than the one mentioned above)
Note on GShint:
GS E hist. int. time. Integration time for the GSPC energy histogram, in
seconds
Note on GSrate:
GS E sample rate. "Energy sampling rate of the GS electronics as a base-two
logarithm, e.g., 11 means 2048 Hz"
Remarks:
The following abbreviations are used throughout the field descriptions:
LE1 First low-energy telescope
LE2 Second low-energy telescope
ME Large area proportional counters, also referred to as the
medium-energy experiment
GSPC (same as GS) Gas-scintillation proportional counter
FOT Final observation tape
OBC On-board computer
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Byte-by-byte Description of file: pinames.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- PInum *P. I. number
5- 30 A26 --- PIname *P. I. name
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Note on PInum:
Code number by which this investigator is identified in the data file
Note on PIname:
Name of the principal investigator
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Remarks and Modifications:
The catalog was first received by the Astronomical Data Center (ADC), NASA
Goddard Space Flight Center, from the Centre de Donnees Astronomiques,
Strasbourg (CDS), in April 1987. A final, corrected version was subsequently
received from ESTEC (Noordwijk) in September 1987. The original tape
consisted of two text files: the first containing the catalog data, the
second containing a list of the names of the principal investigators. ADC
personnel deleted blank columns from the data file to reduce the record size
from 192 to 134 bytes. A FORTRAN program was run to separate the object
names from the data records. The names were reformatted for consistency
using an editor and re-inserted into the data file. Another FORTRAN program
was run to append sequential code numbers to the front of the P. I. name
records. A final FORTRAN program was run to check the validity of each field
according to its data type and value.
References:
de Korte, P. A. J., Bleeker, J. A. M., den Boggende, A. J. F., Branduardi-
Rayrnont, G., Brinkman, A. C., Culhane, J. L., Gronenschild, E. H. B. M.,
Mason, I., and McKechnie, S. P. 1981, Space Science Reviews. 30. 495.
Peacock, A., Andresen, R. D., Manzo, G., Taylor, B. G., Villa, G., Re, S.,
Ives, J. C., and Kellock, S. 1981, Space Science Reviews, 30, 525.
Sternberg, J. R., White, N. E., Barr, P., and Osborne, L. 1986,
EXOSAT Observation Log. (Noordwijk: Estec Printing service, December 1986).
Sternberg, J. R. 1987, unpublished documentation received with the catalog
from the CDS.
Sternberg, J. R. 1987, private communication.
Taylor, B. G. 1985, Advances in Space Research, Vol. 5, No. 3., 35.
Taylor, B. G., Andresen, R. D., Peacock, A., and Zobl, R. 1981, Space
Science Reviews, 30, 479.
Turner, M. J. L., Smith, A., and Zimmermann, H. U. 1981, Space Science
Reviews, 30, 513.
(End) C.-H. Joseph Lyu [Hughes STX/NASA] 16-Aug-1995