B/swift Swift Master Catalog (HEASARC, 2004-)
Swift Master Catalog
Nasa, HEASARC
<The High Energy Astrophysics Science Archive Research Center>
Keywords:
ADC_Keywords: Observatory log ; X-ray sources ; Ultraviolet
Keywords: Ultraviolet, Xray
Mission_Name: Swift
Abstract:
This table records high-level information for each Swift observation and
provides access to the data archive. Each record is associated with a single
observation that contains data from all instruments on board Swift. The BAT is
the large field of view instrument and operates in the 10-300 keV energy band.
The narrow field instruments, XRT and UVOT, operate in the X-ray and UV/optical
regime, respectively.
An observation is defined as a collection of snapshots, where a snapshot is
defined as the time spent observing the same position continuously. Because of
observing constraints, the length of a snapshot can be shorter than a single
orbit and it can be interrupted because the satellite will point in a different
direction of the sky or because the time allocated to that observation ends.
The typical Swift observing strategy for a Gamma Ray Burst (GRB) and/or
afterglow, consists of a serious of observations aimed at following the GRB and
its afterglow evolution. This strategy is achieved with two different type of
observations named Automatic Targets and Pre-Planned Targets. The Automatic
Target is initiated on board soon after an event is triggered by the BAT.
The Figure of Merit (FOM) algorithm, part of the observatory's autonomy,
decides if it is worth requesting a slew maneuver to point the narrow field
instruments (NFI) on Swift, XRT and UVOT, in the direction of the trigger.
If the conditions to slew to the new position are satisfied, the Automatic
Target observation takes place; all the instruments have a pre-set standard
configuration of operating modes and filters and about 20000 seconds on source
will be collected. The Pre-Planned Target observations instead are initiated
from the ground once the trigger is known. These observations are planned on
ground and uploaded onto the spacecraft.
Acknowledging HEASARC:
https://heasarc.gsfc.nasa.gov/docs/heasarc/acknow.html
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . this file
swiftlog.dat 594 5000 SWIFT logs
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Byte-by-byte Description of file: swiftlog.dat
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Bytes Format Units Label Explanations
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1 -60 A60 --- name ? The pointed target name (1)
62- 72 A11 --- obsid ? numerical value assigned
automatically (2)
74- 85 F12.8 deg RAdeg ? Right ascension (J2000) (ra) (3)
87- 98 F12.8 deg DEdeg ? Declination (J2000) (de) (4)
100-112 F13.7 d start_time Start time of the observation
(MJD)(start_time) (5)
114-126 F13.7 d processing_date Date when the data were processed
(MJD) (processing_date)(6)
128-136 F9.3 s xrt_exposure XRT exposure in seconds on source (7)
138-146 F9.3 s uvot_exposure UVOT exposure in seconds on source
(8)
148-156 F9.3 s bat_exposure BAT exposure in seconds on source (9)
158-162 I5 d archive_date ? Date when the data are (expected) to
arrive in the archive (MJD)
(archive_date)(10)
164-170 I7 --- origtargetid Assigned automatically to each target
(11)
172-178 I7 --- ID Uniq identifier for each target
(target_id) (12)
180-194 F15.11 deg roll_angle ? Roll angle of the observation given
(13)
196-208 F13.7 d stop_time Stop time of the observation
(MJD) (stop_time)(14)
210-212 I3 --- origobssegment Number of times a specific target has
been observed (15)
214-216 I3 s obs_segment Number of times a specific target has
been corrected (16)
218-228 A11 --- orig_obsid ? Uniq identifier for observation
(17)
230-237 F8.3 --- xrtexpolr XRT exposure on source in LR mode
(18)
239-245 F7.3 --- xrtexpopu XRT exposure on source in PU mode
(19)
247-254 F8.3 --- xrtexpowt XRT exposure on source in WT mode
(20)
256-264 F9.3 --- xrtexpopc XRT exposure on source in PC mode
(21)
266-270 F5.3 --- xrtexpoim XRT exposure on source in IM mode
(22)
272-280 F9.3 --- uvotexpouu UVOT exposure on source,
filter U (23)
282-289 F8.3 --- uvotexpobb UVOT exposure on source,
filter B (24)
291-298 F8.3 --- uvotexpovv UVOT exposure on source,
filter V (25)
300-308 F9.3 --- uvotexpow1 UVOT exposure on source,
filter UVW1 (26)
310-318 F9.3 --- uvotexpow2 UVOT exposure on source,
filter UVW2 (27)
320-328 F9.3 --- uvotexpom2 UVOT exposure on source,
filter UVM2 (28)
330-338 F9.3 --- uvotexpowh UVOT exposure on source,
filter White (29)
340-347 F8.3 --- uvotexpogu UVOT exposure on source,
filter UGRISM (30)
349-351 F3.1 --- uvotexpogv UVOT exposure on source,
filter VGRISM (31)
353-355 F3.1 --- uvotexpomg UVOT exposure on source,
filter Magnifier (32)
357-364 F8.3 --- uvotexpobl ? UVOT exposure on source,
filter blocking (33)
366-373 F8.3 --- batexpoev BAT exposure on source in mode
EVENT (34)
375-381 F7.1 --- batexposv BAT exposure on source in mode
SURVEY (35)
383-389 F7.1 --- batexport BAT exposure on source in mode
RATE (36)
391-397 F7.1 --- batexpomt BAT exposure on source in mode
MASKTAG (37)
399-405 F7.1 --- batexpopl BAT exposure on source in mode
PULSAR (38)
407-408 I2 --- batnomasktag ? BAT exposure on source in mode
MASKTAG (39)
410-471 A62 --- software_version ? version of the HEAsoft and Swift
software (40)
473-479 A7 --- processing_version ? version of the processing script
(41)
481-482 I2 --- num_processed Number of times a data set has been
processed (42)
484-491 I8 --- prnb Proposal number of the observation
(43)
493-512 A20 --- pi ? Principal Investigator (44)
514-517 A4 --- att_flag ? Flags the attitude solution for
crossmatching positions (45)
519-519 A1 --- tdrss_flag ? Y if TDRSS messages containing the
first science information (46)
521-521 A1 --- grb_flag ? Y if the observation contains data
from a gamma-ray burst (47)
523-534 F12.8 --- Glon ? Galactic Longitude (lii) (48)
536-547 F12.8 --- Glat ? Galactic Latitude (bii) (49)
549-565 E17.12 --- saa_fraction ? Fraction of observing time spent in
the SAA (50)
567-582 F16.10 --- af_total ? Total time allocated for this
sequence (51)
584-600 F17.11 --- af_onsource ? Total time spent on source for this
sequence (52)
602-616 F15.10 --- af_inslew ? Total time spent in slews for this
sequence (53)
618-635 F18.12 --- af_insaa ? Total time spent in the SAA during
the observation (54)
637-638 I2 --- cycle ? Proposal cycle number of the
observation (55)
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Note (1): This is the name of the pointed target. For GRBs, the name is assigned
following the convention "GRBYYMMDD" or "GRBYYMMDDn" if multiple bursts occur
within a day, where n is a letter.
Note (2): This parameter contains a numeric value that uniquely identifies an
observation. This value is the combination of the numerical value assigned to a
target and the observation segment and is derived from the parameters target_id
and obs_segment. The numerical value is a fixed 11-digit number, where the first
143 are for the target and last 3 are for the observation segment.
Note (3): Right Ascension of the pointing position. Note that the pointing
position can be different from the GRB (or other target) position.
Note (4): Declination of the pointing position. Note that the pointing position
can be different from the GRB (or other target) position.
Note (5): Start time of the observation. Note that the date associated with the
observation always contains the incoming slew.
Note (6): This records the date when the data were processed. If a data set has
been processed more than one time, it reports the date of the last processing.
Note (7): The XRT exposure in seconds on source. The XRT collect science data
in 5 different modes: Low-Rate Photodiode (LR), Piled-Up Photodiode (PU),
Windowed Timing (WT), Photon Counting (PC) and Imaging (IM). These modes cannot
be run simultaneously. The xrt_exposure is calculated as the sum of the
exposures on source of all the science XRT modes used within this observation.
If none of the science modes are used, this field is set to zero.
Note (8): The UVOT exposure in seconds on source. The UVOT operates with 10
different filters (U, V, B, UVW1, UVW2, UVM2, White, Vgrism, Ugrism and
Magnifier) in three different science modes (EVENT, IMAGE and EVENTIMAGE). The
modes always use a filter and they can not be run simultaneously. The
uvot_exposure is calculated as the sum of the exposures on source of all filters
used within one observation regardless of the mode. If none of the science modes
are used, this field is set to zero.
Note (9): The BAT exposure in seconds on source. The BAT can run simultaneously
several modes. The main modes are the EVENT and SURVEY modes and they are
alternated within an observation (never run simultaneously). Within an
observation the EVENT mode is used when detecting a burst, otherwise the BAT
collect data in the SURVEY mode. The bat_exposure on source is calculated as the
sum of the effective exposure on source of the EVENT and SURVEY modes.
Note (10): The archive_date is the date when the data are (expected) to arrive
in the archive. There is a delay of about one week between the time when the
data arrive on ground and are processed and when the data are sent to the
archive. Therefore, observations made by Swift within about a week of the
present are listed in this table, but the actual data files will arrive in the
archive within a week.
Note (11): This is a numerical value assigned automatically to each target and
corresponds to the trigger number. In a few cases the same target_id may be
assigned to different sky positions. Any target_id degeneracy is removed on the
ground (see target_id parameter). The numerical value follows the convention
adopted for Swift to assign the target identification. The numerical values can
include up to 8 digits.
Note (12): This is a unique numerical value assigned to each target and
corresponds to the trigger number. This value is first assigned on board, but
to remove the degeneracy in the assignment of target_id for the safe pointing
position and/or to correct any wrong assignment of the target_id, the unique (or
the correct) number is re-assigned on ground and stored in the target_id
parameter. In these cases origtargetid and target_id do not contain the same
values; otherwise, they are identical. The numerical value follows the
convention adopted for Swift to assign the target identification. The numerical
values can include up to 8 digits.
Note (13): Roll angle of the observation given in degrees.
Note (14): Stop time of the observation. For an Automatic Target, the stop time
typically is after the satellite spends 20000 seconds exposure on source.
Note (15): The Swift observation strategy is similar to a monitoring campaign,
where a target is observed several times. The observation segment, recorded in
this parameter, corresponds to the number of times a specific target has been
observed. The numerical value follows the convention adopted for Swift to assign
the observation segments and can include up to 3 digits. The first value for the
segment is zero and is set on-board for the Automatic Target observation.
Note (16): Observation Segment. The Swift observation strategy is similar to a
monitoring campaign, where a target is observed several times. This parameter
corresponds to the number of times a specific target has been observed and
contains a value which has been corrected for any erroneous assignment. This
re-assignment is done on the ground after the observation has been performed.
If this was necessary the origobssegment and obs_segment do not contain the
same values; otherwise, they are identical. The numerical value follows the
convention adopted for Swift for assigning the observation segments and can
include up to 3 digits. The initial value for the segment is zero and is set
on-board for the Automatic Target observation.
Note (17): This parameter contains a numeric value that should uniquely identify
an observation. This value is the combination of the numerical value assigned to
a target and the observation segment and is derived from the parameters
origtargetid and origobssegment. Since these can be assigned incorrectly
or may not be unique, the orig_obsid can also be wrong or not unique.
The numerical value is a fixed 11-digit number, where the first 8 are for the
target and last 3 are for the observation segment.
Note (18): The XRT exposure on source when the Low-Rate Photodiode (LR) mode was
in use. If there are no data taken with the LR mode, this field is set to zero.
Note (19): The XRT exposure on source when the Piled-Up Photodiode (PU) mode was
in use. If there are no data taken with the PU mode, this field is set to zero.
Note (20): The XRT exposure on source when the Windowed Timing (WT) mode was in
use. If there are no data taken with the WT mode, this field is set to zero.
Note (21): The XRT exposure on source when the Photon Counting (PC) mode was in
use. If there are no data taken with the PC mode, this field is set to zero.
Note (22): The XRT exposure on source when the IMAGE (IM) mode was in use. If
there are no data taken with the IM mode, this field is set to zero.
Note (23): The UVOT exposure on source when the U filter was in use. If there
are no data taken with the U filter, this field is set to zero.
Note (24): The UVOT exposure on source when the B filter was in use. If there
are no data taken with the B filter, this field is set to zero.
Note (25): The UVOT exposure on source when the V filter was in use. If there
are no data taken with the V filter, this field is set to zero.
Note (26): The UVOT exposure on source when the UVW1 filter was in use. If
there are no data taken with the UVW1 filter, this field is set to zero.
Note (27): The UVOT exposure on source when the UVW2 filter was in use. If
there are no data taken with the UVW1 filter, this field is set to zero.
Note (28): The UVOT exposure on source when the UVM2 filter was in use. If
there are no data taken with the UVM2 filter, this field is set to zero.
Note (29): The UVOT exposure on source when the White filter was in use. If
there are no data taken with the White filter, this field is set to zero.
Note (30): The UVOT exposure on source when the UGRISM filter was in use. If
there are no data taken with the UGRISM filter, this field is set to zero.
Note (31): The UVOT exposure on source when the VGRISM filter was in use. If
there are no data taken with the VGRISM filter, this field is set to zero.
Note (32): The UVOT exposure on source when the Magnifier filter was in use. If
there are no data taken with the Magnifier filter, this field is set to zero.
Note (33): The UVOT exposure on source when the blocking filter was in use. If
there are no data taken with the blocking filter, this field is set to zero.
Note (34): The BAT exposure on source when the EVENT mode was in use. Typically,
this mode is used when a new trigger is detected. If there are no data taken
with the EVENT mode, this field is set to zero.
Note (35): BAT exposure on source when the SURVEY mode was in use. Typically
this mode is always running during a Pre-Planned target observation or used
after the EVENT mode for an Automatic Target observation. If there are no data
taken with the SURVEY mode, this field is set to zero.
Note (36): BAT exposure on source when the RATE mode was in use. If there are no
data taken with the RATE mode, this field is set to zero.
Note (37): Cumulative BAT exposure of all sources tagged with the MASKTAG mode.
The MASKTAG mode is used to obtain rates in different energy band for a specific
source. Within an observation rates for several sources can be tagged
simultaneously using this mode. This field records the total exposure for all
sources taken with the MASKTAG mode. The batnomasktag parameter records the
number of sources for which there are MASKTAG mode data. On average the exposure
per single source is obtained by dividing the cumulative MASKTAG
exposure,batexpomt, by the number of sources, batnomasktag. Typically one of
the sources tagged with this mode within an observation corresponds to the
GRB position.
Note (38): BAT exposure on source when the PULSAR mode was in use. If there are
no data taken with the PULSAR mode, this field is set to zero.
Note (39): Number of sources for which the MASKTAG rate mode is used within this
observation.
Note (40): This records the version of the HEAsoft and Swift software used to
process the observation data.
Note (41): This records the version of the processing script used in the
pipeline to generate the data products from the observation.
Note (42): This records the number of times a data set has been processed using
the same processing version of the script.
Note (43): The proposal number of the observation. This field contains a value
other than 1 only when the observation was requested via the GO program.
Note (44): Principal Investigator. If the Swift Announcement of Opportunity for
proposals allows an observer to request a pointing, this field contains the
name of the proposer. It is set to Swift for all other observations.
Note (45): The UVOT data provides a different attitude solution by matching the
observed position with known catalogued stars. When that is possible, this flag
is set to Y and indicates that an attitude reconstructed using the UVOT data is
available. This however does not mean that it applies to all data. Currently,
this attitude is not available and the flag is empty.
Note (46): This flag is set to Y if TDRSS messages containing the first science
information on the burst were sent to the ground during the observation.
Note (47): This flag is set to Y if the observation contains data from a
gamma-ray burst.
Note (48): Galactic Longitude of the pointing position. Note that the pointing
position can be different from the GRB (or other target) position.
Note (49): Galactic Latitude of the pointing position. Note that the pointing
position can be different from the GRB (or other target) position.
Note (51): This parameter reports the total time allocated for this sequence.
It is derived from the Swift as-flown timeline. The value is given in seconds
and includes the time spent on source and during the slews.
Note (52): This parameter reports the total time spent on source for this
sequence. It is derived from the Swift as-flown timeline. The value is given in
seconds and may be different from the total exposure on source reported by each
instrument.
Note (53): This parameter reports the total time spent in slews for this
sequence. It is derived from the Swift as-flown timeline. The value is given
in seconds.
Note (54): This parameter reports the total time spent in the SAA during the
observation. It is derived from the Swift as-flown timeline. The value is given
in seconds and includes the time spent in the SAA, whether it occurs on source
or during slews.
Note (55): The proposal cycle number of the observation. Starting with cycle 3
observers can request pointings (initially only TOO). If the observation was not
requested via the GO program, the value of this parameter is set to 1.
Note (50): This parameter reports the fraction of observing time spent in the
SAA (South Atlantic Anomaly). This value is derived from the Swift timeline and
is calculated as the ratio of the time flagged as in the SAA with the total
observing time for each sequence. The values range from 0-1, where 0 indicates
that no time was spent in the SAA during the observation.
See also:
https://swift.gsfc.nasa.gov/about_swift/ : the HEASARC web pages
Acknowledgements:
It is a pleasure to thank HEASARC, who provided us with access to build
this catalogue.
(End) Gilles Landais [CDS] 30-Jan-2018