J/ApJ/818/110 Short GRBs with Fermi GBM and Swift BAT (Burns+, 2016)
Do the Fermi Gamma-ray Burst Monitor and Swift Burst Alert Telescope see the
same short gamma-ray bursts?
Burns E., Connaughton V., Zhang B.-B., Lien A., Briggs M.S., Goldstein A.,
Pelassa V., Troja E.
<Astrophys. J., 818, 110 (2016)>
=2016ApJ...818..110B 2016ApJ...818..110B (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays
Keywords: gamma-ray burst: general
Abstract:
Compact binary system mergers are expected to generate gravitational
radiation detectable by ground-based interferometers. A subset of
these, the merger of a neutron star with another neutron star or a
black hole, are also the most popular model for the production of
short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT)
and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs
(SGRBs) at rates that reflect their relative sky exposures, with the
BAT detecting 10 per year compared to about 45 for GBM. We examine the
SGRB populations detected by Swift BAT and Fermi GBM.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 28 160 GBM SGRBs as viewed by BAT
table2.dat 32 41 Event information for GBM SGRBs untriggered in BAT
table3.dat 23 54 BAT SGRBS as viewed by GBM
table4.dat 53 7 The seven BAT SGRBs untriggered in GBM
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See also:
J/ApJS/199/18 : The Fermi GBM catalog (Paciesas+, 2012)
J/ApJ/763/15 : Fermi GRB analysis. III. T90 distributions (Qin+, 2013)
J/ApJ/787/66 : Burst duration measurements for a GRB sample (Zhang+, 2014)
J/ApJS/216/32 : Localizations of GRBs with Fermi GBM (Connaughton+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- Trig ? Trigger number (<Fermi bnYYMMDDddd> in SIMBAD)
11- 17 A7 --- GRB GRB name ( in SIMBAD)
19- 23 F5.1 --- Area Percent of the GBM localization contours with
the 10% BAT coded FoV
25- 28 A4 --- Flag BAT operating flag (G1)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- Trig Trigger number (<Fermi bnYYMMDDddd> in SIMBAD)
11- 14 A4 --- Flag [Slew] BAT operating flag (G1)
16- 21 F6.2 s Start ? Event data start (1)
23- 28 F6.2 s Total ? Event data total (2)
30- 32 F3.1 --- SNR ? Maximum of signal-to-noise ratio (3)
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Note (1): Event start time relative to GBM trigger.
Note (2): Total number of seconds during this event file.
Note (3): Highest SNR within the GBM contours. Event information is not given
for cases where the processing script did not complete and report
an SNR>4.0.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB SGRB name ( in SIMBAD) (1)
9- 17 I9 --- Trig ? Trigger number (<Fermi bnYYMMDDddd> in SIMBAD)
19 A1 --- EO [x] Earth occultation (2)
21 A1 --- SAA [x] South Atlantic Anomaly (2)
23 A1 --- m [x] Missed (2)
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Note (1): List of all BAT SGRBs within our time window with the GBM trigger
number if it was also detected by the GBM.
Note (2): If the trigger was not found by GBM then it was checked if the
location was occulted by the Earth, occurred during transit of the
South Atlantic Anomaly (SAA), and if it was neither then the trigger
was missed.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB ? GRB name ( in SIMBAD)
9- 12 F4.2 s T90 [0.19/1.36] T90 duration (1)
14- 17 F4.1 --- flnc [8.5/61.0] Fluence (2)
19- 22 F4.1 --- Fp [6.7/64.0] Peak flux (2) (3)
24- 27 F4.2 --- PL [0.53/2.23] Spectral power law index (BAT)
29- 31 I3 --- PC [50/100] Partial coding value (4)
33- 35 I3 deg off [14/135] Fermi LAT boresight offset angle
37 I1 --- Det ? Number of GBM NaI detectors (5)
39- 46 A8 --- n_Det The two lowest observation angles
from NaI detector normal (6)
48- 53 A6 --- Sig [Strong/Weak/None]? Ground signal (7)
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Note (1): Length of time between 5% and 95% of the cumulative fluence of the
burst. No T90 error is greater than 0.3s, placing them all firmly
in the SGRB category.
Note (2): The percentile rankings are calculated from the sample of all BAT
SGRBs. Both measures of brightness are in the 15-150 keV band.
Note (3): The peak flux is the 1s peak photon flux which is not ideal for short
bursts but gives an estimate of the GRB brightness.
Note (4): Fraction of BAT detectors exposed to a position on the sky.
Note (5): The number of NaI detectors refers to the number of GBM NaI detectors
that have the burst location within their FoV.
Note (6): We exclude all detectors whose view was obstructed by the LAT (Large
Area Telescope) or the spacecraft.
Note (7):
Strong = Strong signals are for SGRBs that GBM could claim detection alone
Weak = Weak signals denote SGRBs that GBM would claim detection only if the
SGRB was also detected by another instrument.
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Global Notes:
Note (G1): BAT operating flag defined as follows:
Slew = When triggering is disabled
SAA = South Atlantic Anomaly passage
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History:
From electronic version of the journal
(End) Marianne Brouty [CDS] 11-Jan-2018