| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB181231144 |
|
| T0 |
3:27:36.833 UTC |
Fermi_GBM |
| ra |
254.5917° |
IPN |
| decl |
0.6167° |
IPN |
| pos_error |
2.33e-01° |
IPN |
| T90 |
36.865 s |
Fermi_GBM |
| T90_error |
3.665 s |
Fermi_GBM |
| T90_start |
3:27:36.833 UTC |
Fermi_GBM |
| fluence |
4.09e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
4.19e-08 erg/cm² |
Fermi_GBM |
| T100 |
36.865 s |
|
| GBM_located |
False |
|
| mjd |
58483.14417630787 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB181231144 |
| trigger_name |
bn181231144 |
| ra |
254.5900° |
| decl |
0.6100° |
| pos_error |
5.85e+00° |
| datum |
2018-12-31 |
| t_trigger |
3:27:43.745 UTC |
| T90 |
36.865 s |
| T90_error |
3.665 s |
| T90_start |
3:27:36.833 UTC |
| fluence |
4.09e-06 erg/cm² |
| fluence_error |
4.19e-08 erg/cm² |
| flux_1024 |
2.70e+00 erg/cm²/s |
| flux_1024_error |
2.69e-01 erg/cm²/s |
| flux_1024_time |
1.43e+01 erg/cm²/s |
| flux_64 |
5.75e+00 erg/cm²/s |
| flux_64_error |
1.67e+00 erg/cm²/s |
| IPN table |
|---|
| GRB_name |
GRB181231A |
| ra |
254.5917° |
| decl |
0.6167° |
| pos_error |
2.33e-01° |
| GCN 23597 table |
|---|
| GRB_name |
GRB181231A |
| GCN_number |
23597 |
| Detection_method |
Fermi LAT Det |
| t_trigger |
3:27:43.800 UTC |
| ra |
254.5900° |
| decl |
0.6100° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23597
SUBJECT: GRB 181231A: Fermi-LAT detection
DATE: 18/12/31 17:55:29 GMT
FROM: Masanori Ohno at Hiroshima University
F. Dirirsa (U. Johannesburg) and M. Ohno (Hiroshima U.)
report on behalf of the Fermi-LAT team:
On December, 31, 2018 Fermi-LAT detected high-energy emission from GRB
181231A, which was also detected by Fermi-GBM (trigger 567919668 /
181231144).
The best LAT on-ground location is found to be
RA, Dec = 254.59, 0.61 (degrees, J2000)
with an error radius of 0.24 deg (90 % containment, statistical error
only).
This was 51 deg from the LAT boresight at the time of the GBM trigger:
T0 = 03:27:43.8 UT.
The data from the Fermi-LAT show a significant increase
in the event rate after the GBM trigger that is spatially correlated with
the
GBM emission (7.8 degrees from the GBM location) with high significance.
The photon flux above 100 MeV in the time interval 0-5000 s after the
GBM trigger is 2.4 (+/-1.2)E-6 ph/cm2/s.
The estimated photon index above 100 MeV is 2.21 (+/-0.37).
A Swift ToO has been requested for this burst
The Fermi-LAT point of contact for this burst is Feraol F. Dirirsa (
fdirirsa@uj.ac.za).
The Fermi-LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S. and many
scientific institutions across France, Italy, Japan and Sweden.
|
| GCN 23598 table |
|---|
| GRB_name |
GRB181231A |
| GCN_number |
23598 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
3:27:43.750 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23598
SUBJECT: GRB 181231A: Fermi GBM detection
DATE: 18/12/31 18:56:12 GMT
FROM: Peter Veres at UAH
P. Veres, R. Hamburg and C. Meegan (all UAH)
report on behalf of the Fermi GBM Team:
"At 03:27:43.75 UT on 31 December 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 181231A (trigger 567919668 / 181231144)
which was also detected by Fermi/LAT (Dirirsa et al., GCN 23597).
The GBM on-ground location is consistent with the LAT position.
The GBM light curve shows multiple peaks
with a duration (T90) of about 37 s (50-300 keV).
The time-averaged spectrum from T0-7.2 s to T0+30.7 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.63 +/- 0.13 and
the cutoff energy, parameterized as Epeak, is 215 +/- 25 keV.
The event fluence (10-1000 keV) in this time interval is
(6.23 +/- 0.46)E-6 erg/cm^2. The 1 second peak photon flux measured
starting from T0+14.3 s in the 10-1000 keV band
is 2.70 +/- 0.27 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|
| GCN 23599 table |
|---|
| GRB_name |
GRB181231A |
| GCN_number |
23599 |
| Detection_method |
Optical |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23599
SUBJECT: GRB 181231A: BOOTES-2/TELMA optical observations
DATE: 19/01/01 12:28:58 GMT
FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia
Y.-D. Hu, X.-Y.Li, E. Fernandez-Garcia, A. Ayala, A. J. Castro-Tirado
(IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de
Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC), M.D. Caballero-Garcia and
M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report:
The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC)
in Algarrobo Costa (Malaga, Spain) followed up GRB 181231A (Veres et al
GCNC 23598). Nine images (60s exposure, unfiltered) were obtained with
the COLORES imager spectrograph starting at 05:35:26 UT (~26.1 hr after
trigger) in order to cover the entire Fermi/LAT error box (Dirirsa et
al. GCNC 23597). No new optical sources were detected down to 18 mag.
This message can be quoted.
|