J/A+A/685/A163 Simulated realistic detection of GRBs (Llamas Lanza+, 2024)
High-z gamma-ray burst detection by SVOM/ECLAIRs:
Impact of instrumental biases on the bursts' measured properties.
Llamas Lanza M., Godet O., Arcier B., Yassine M., Atteia J.-L., Bouchet L.
<Astron. Astrophys. 685, A163 (2024)>
=2024A&A...685A.163L 2024A&A...685A.163L (SIMBAD/NED BibCode)
ADC_Keywords: GRB ; Models ; Redshifts
Keywords: gamma-ray burst: general - galaxies: high-redshift
Abstract:
Gamma-ray bursts (GRBs) can be detected at cosmological distances, and
therefore can be used to study the contents and phases of the early
Universe. The 4-150keV wide-field trigger camera ECLAIRs on board
the Space-based multi-band Variable Object Monitor (SVOM) mission,
dedicated to studying the high-energy transient sky in synergy with
multi-messenger follow-up instruments, has been adapted to detect
high-z GRBs.
Investigating the detection capabilities of ECLAIRs for high-redshift
GRBs and estimating the impacts of instrumental biases in
reconstructing some of the source measured properties, focusing on GRB
duration biases as a function of redshift.
We simulated realistic detection scenarios for a sample of 162 already
observed GRBs with known redshift values as they would have been seen
by ECLAIRs. We simulated them at redshift values equal to and higher
than their measured value. Then we assessed whether they would be
detected with a trigger algorithm resembling that on board ECLAIRs,
and derived quantities, such as T90, for those that would have been
detected.
We find that ECLAIRs would be capable of detecting GRBs up to very
high redshift values (e.g. 20 GRBs in our sample are detectable within
more than 0.4 of the ECLAIRs field of view for zsim>12). The ECLAIRs
low-energy threshold of 4keV, contributes to this great detection
capability, as it may enhance it at high redshift (z>10) by over 10%
compared with a 15keV low-energy threshold. We also show that the
detection of GRBs at high-z values may imprint tip-of-the-iceberg
biases on the GRB duration measurements, which can affect the
reconstruction of other source properties.
Description:
We simulated realistic detection scenarios for a sample of 162 already
observed GRBs with known redshift values as they would have been seen
by ECLAIRs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 25 162 Swift/BAT GRBs analysed in this study
tablee1.dat 40 162 General results for each GRB in the sample
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 ---- GRB GRB name (NNNNNNA)
10- 13 F4.2 --- zmeas Measured redshift
16- 20 F5.1 s T90obs Observed duration of the time interval over
which 90% (T_90obs)
23- 25 A3 --- Fermi [Yes ] Yes if a corresponding Fermi/GBM
detection was found, and therefore whether
its derived spectrum was used
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Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- GRB GRN Name (NNNNNNA)
10- 14 F5.1 --- iS/Nmed Median of the iS/N value (1)
17- 21 F5.1 s T90obs ?=- Observed duration of the time interval
over which 90% (T_90obs) (1)
24- 28 F5.1 % FFoV ?=- Detectable fraction of the FoV (1)
31- 34 F4.1 % zhor ?=- Redshift horizon (1)
37- 40 F4.2 --- Frac ?=- T90src(zhor)/T90src(zmeas)
value (1)
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Note (1): The values of T90obs, iS/N, and the detectable fraction of the FoV
(FFoV) correspond to those at zmeas.
All values, except for FFoV, refer to the results within the fcFoV.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Jul-2024