| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB180806944 |
|
| T0 |
22:38:58.637 UTC |
Fermi_GBM |
| ra |
11.5536° |
GCN_circulars,Swift-XRT Other |
| decl |
24.3370° |
GCN_circulars,Swift-XRT Other |
| T90 |
15.616 s |
Fermi_GBM |
| T90_error |
0.81 s |
Fermi_GBM |
| T90_start |
22:38:58.637 UTC |
Fermi_GBM |
| fluence |
2.24e-05 erg/cm² |
Fermi_GBM |
| fluence_error |
3.70e-08 erg/cm² |
Fermi_GBM |
| T100 |
15.616 s |
|
| GBM_located |
False |
|
| mjd |
58336.94373422454 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB180806944 |
| trigger_name |
bn180806944 |
| ra |
11.5538° |
| decl |
24.3369° |
| pos_error |
2.55e+00° |
| datum |
2018-08-06 |
| t_trigger |
22:38:59.661 UTC |
| T90 |
15.616 s |
| T90_error |
0.81 s |
| T90_start |
22:38:58.637 UTC |
| fluence |
2.24e-05 erg/cm² |
| fluence_error |
3.70e-08 erg/cm² |
| flux_1024 |
1.43e+01 erg/cm²/s |
| flux_1024_error |
3.15e-01 erg/cm²/s |
| flux_1024_time |
4.93e+00 erg/cm²/s |
| flux_64 |
1.69e+01 erg/cm²/s |
| flux_64_error |
1.30e+00 erg/cm²/s |
| IPN table |
|---|
| GRB_name |
GRB180806A |
| ra |
11.5542° |
| decl |
24.3333° |
| pos_error |
4.67e+00° |
| GCN 23093 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23093 |
| Detection_method |
Swift Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23093
SUBJECT: GRB 180806A: Swift ToO observations
DATE: 18/08/07 14:37:16 GMT
FROM: Phil Evans at U of Leicester
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/GBM GRB 180806A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020812
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/GBM event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
|
| GCN 23095 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23095 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
22:38:59.660 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23095
SUBJECT: GRB 180806A: Fermi GBM detection
DATE: 18/08/07 17:35:57 GMT
FROM: Christian Malacaria at U of Alabama/MSFC
C. Malacaria (NASA-MSFC/USRA), R. Hamburg (UAH), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 22:38:59.66 UT on 06 August 2018, the Fermi Gamma-Ray Burst
Monitor triggered and located GRB 180806A
(trigger 555287944 / 180806944).
The event was also possibly detected by MASTER OT
(Lipunov et al. 2018, GCN 23091) and COATLI (Watson et al. 2018,
GCN 23092, GCN 23094) and triggered a Swift/XRT ToO
(Evans et al. 2018, GCN 23093).
The GBM on-ground location and the MASTER position are consistent.
The angle from the Fermi LAT boresight at the
GBM trigger time is 66 degrees.
The GBM light curve consists of a single peak
with a duration (T90) of about 15.6 +/- 0.8 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+16.9 s is
best fit by a Band function with Epeak = 482.40 +/- 31.2,
alpha index = -0.95 +/- 0.02 and beta index = -2.37 +/- 0.19.
The event fluence (10-1000 keV) in this time interval is
(2.197 +/- 0.039)E-05 erg/cm^2. The 1-sec peak photon flux
Measured starting from T0+4.9 s in the 10-1000 keV band
is 14.3 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|
| GCN 23097 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23097 |
| Detection_method |
Swift-XRT Other |
| ra |
11.5536° |
| decl |
24.3370° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23097
SUBJECT: GRB 180806A: Swift-XRT afterglow detection
DATE: 18/08/07 22:15:00 GMT
FROM: Antonino D'Ai at IASF-PA
S.L. Gibson (U. Leicester), Z. Liu (NAOC / U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU) and P.A. Evans
(U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Fermi/GBM-detected burst GRB 180806A (Malacaria et al. GCN Circ.
23095), collecting 1.8 ks of Photon Counting (PC) mode data between
T0+57.6 ks and T0+76.2 ks.
Two uncatalogued X-ray sources are detected, of which one ("Source 1")
is fading with 3-sigma significance, and is therefore likely the GRB
afterglow. The position of this source is RA, Dec=11.5536, +24.3370
which is equivalent to:
RA (J2000): 00:46:12.86
Dec(J2000): +24:20:13.2
with an uncertainty of 5.0 arcsec (radius, 90% confidence).
This position is 1.3 arcsec from the Fermi/GBM position and 2.7 arcsec
from the OT position reported by Lipunov (GCN 23091) and Watson (GCN
23092).
The source is fading with alpha >2.2.
The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00020812/Source1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020812.
This circular is an official product of the Swift-XRT team.
|
| GCN 23098 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23098 |
| Detection_method |
Optical |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23098
SUBJECT: GRB 180806A: NOT optical observations
DATE: 18/08/08 02:13:55 GMT
FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst
Daniele Bjørn Malesani (DAWN/NBI and DARK/NBI) and Ana Sagues (NOT) report:
We observed the candidate optical counterpart (Lipunov et al., GCN
23091; Watson et al., GCN 23092) of the Fermi GRB 180806A (Malacaria et
al., GCN 23095) using the Nordic Optical Telescope (NOT) equipped with
the AlFOSC camera.
In a single 300 s exposure centered on 2018 Aug 8.07 UT (27.09 hr after
the GRB), we detect the candidate afterglow with a magnitude r = 22.31
+- 0.10 AB, calibrated against nearby stars from the Pan-STARRS catalog.
The continued fading compared to previous reports (Lipunov et al., GCN
23091; Butler et al., GCN 23094; Watson et al., GCN 23096), as well as
the spatial coincidence with an X-ray source (Gibson et al., GCN 23097)
confirm the interpretation of this source as the optical afterglow of
GRB 180806A.
|
| GCN 23101 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23101 |
| Detection_method |
correction |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23101
SUBJECT: GRB180806A: correction to Circular 23097
DATE: 18/08/08 21:30:10 GMT
FROM: Antonino D'Ai at IASF-PA
A. D'Ai (INAF/Iasf-PA) reports on behalf of the Swift/XRT Team:
this is a correction to the recent GCN Circ 23097 (S.L. Gibson et al).
The angular distance between the “Source 1" position and the
Fermi/GBM final position was incorrectly reported.
The distance is 4.3 deg, not 1.3 arcsec.
We thank Alan Watson for spotting the error and we apologize for any inconvenience.
|
| GCN 23119 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23119 |
| Detection_method |
Konus-Wind Det |
| t_trigger |
22:39:04.190 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23119
SUBJECT: Konus-Wind observation of GRB 180806A
DATE: 18/08/10 15:33:07 GMT
FROM: Anastasia Tsvetkova at Ioffe Institute
A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 180806A
(Fermi GBM detection: Malacaria et al., GCN 23095)
triggered Konus-Wind at T0=81544.19 s UT (22:39:04.190).
The burst light curve shows a single pulse with a total duration of ~20 s.
The emission is seen up to ~1.2 MeV.
As observed by Konus-Wind, the burst
had a fluence of 2.92(-0.36,+0.41)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+5.712 s,
of 5.52(-1.59,+1.66)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+7.424 s)
is best fit in the 20 keV - 16 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.76(-0.14,+0.16),
the high energy photon index beta = -2.56(-0.79,+0.32),
the peak energy Ep = 352(-53,+59) keV,
chi2 = 90/94 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180806_T81544/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
|
| GCN 23122 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23122 |
| Detection_method |
AstroSat CZTI |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23122
SUBJECT: GRB 180806A: AstroSat CZTI detection
DATE: 18/08/10 17:58:28 GMT
FROM: Vidushi Sharma at IUCAA
V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of AstroSat CZTI data showed the detection of a long GRB 180806A, which was also detected by Fermi-GBM (Malacaria C. et al., GCN 23095) and Konus-Wind (Tsvetkova A. et al., GCN 23119).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 22:39:04.500 UT. The measured peak count rate is 994 cts/s above the background in combined data of four quadrants, with a total of 9327 cts. The local mean background count rate was 498 cts/s. Using cumulative rates, we measure a T90 of 25.8 s. In preliminary analysis, we find that 623 compton events are associated with this event.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
|
| GCN 23157 table |
|---|
| GRB_name |
GRB180806A |
| GCN_number |
23157 |
| Detection_method |
Swift-XRT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23157
SUBJECT: GRB180806A: confirmation of the X-ray afterglow
DATE: 18/08/19 22:26:22 GMT
FROM: Antonino D'Ai at IASF-PA
A. D'Ai (IASF-PA) reports on behalf of the Swift/XRT team:
Swift has performed further observations of the field of the
Fermi/LAT-detected burst GRB 180806A (Malacaria et al., GCN 23095).
An additional 4.2 ks of data were collected between 11.4 days
and 12.0 days after the Fermi trigger.
Source 1, initially reported by Gibson et al. (GCN 23097)
as the likely X-ray counterpart, is no longer detected down to a 3-sigma
upper limit of 1.0e-2 ct s^-1. Source 1 position was also consistent with an
optically fading source (GCN 23091, 23092, 23094, 23096, 23098, 23101).
Source1 is therefore confirmed as the X-ray afterglow of GRB 180806A.
This circular is an official product of the Swift-XRT team.
|