| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB090418816 |
|
| T0 |
19:35:24.854 UTC |
Fermi_GBM |
| ra |
262.8000° |
Fermi_GBM |
| decl |
-28.2000° |
Fermi_GBM |
| pos_error |
9.51e+00° |
Fermi_GBM |
| T90 |
0.32 s |
Fermi_GBM |
| T90_error |
0.405 s |
Fermi_GBM |
| T90_start |
19:35:24.854 UTC |
Fermi_GBM |
| fluence |
1.82e-07 erg/cm² |
Fermi_GBM |
| fluence_error |
3.26e-08 erg/cm² |
Fermi_GBM |
| T100 |
0.32 s |
|
| GBM_located |
True |
|
| mjd |
54939.81625988426 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB090418816 |
| trigger_name |
bn090418816 |
| ra |
262.8000° |
| decl |
-28.2000° |
| pos_error |
9.51e+00° |
| datum |
2009-04-18 |
| t_trigger |
19:35:24.918 UTC |
| T90 |
0.32 s |
| T90_error |
0.405 s |
| T90_start |
19:35:24.854 UTC |
| fluence |
1.82e-07 erg/cm² |
| fluence_error |
3.26e-08 erg/cm² |
| flux_1024 |
1.68e+00 erg/cm²/s |
| flux_1024_error |
2.43e-01 erg/cm²/s |
| flux_1024_time |
-3.20e-01 erg/cm²/s |
| flux_64 |
5.88e+00 erg/cm²/s |
| flux_64_error |
1.27e+00 erg/cm²/s |
| GCN 9184 table |
|---|
| GRB_name |
GRB090418C |
| GCN_number |
9184 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
19:35:24.920 UTC |
| ra |
262.8000° |
| decl |
-28.3000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 9184
SUBJECT: GRB 090418C: Fermi GBM Detection
DATE: 09/04/22 01:08:13 GMT
FROM: Valerie Connaughton at MSFC
Valerie Connaughton (UAH) reports on behalf of the Fermi GBM Team:
"At 19:35:24.92 UT on 18 April 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090418C (trigger 261776126 / 090418816).
The on-ground calculated location, using the GBM trigger
data, is RA = 262.8, DEC = -28.3 (J2000 degrees,
equivalent to 17 h 31 m, -28 d 18 '), with an uncertainty
of 14.4 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 58 degrees.
The GBM light curve shows a short, double-peaked burst
with a duration (T90) of about 0.6 s (8-1000 keV).
The time-averaged spectrum from T0-0.128 s to T0+0.256 s is
well fit by a power law with index -1.27 +/- 0.04, though
formally it is best fit by a power law function with an exponential
high energy cutoff. The power law index in this case
is -0.94 +/- 0.08 and the cutoff energy, parameterized as Epeak,
lies above 1 MeV.
The event fluence (8-1000 keV) in this time interval is
(6.0 +/- 0.3)E-7 erg/cm^2. The 0.128-sec peak photon flux measured
starting from T0-0.128 s in the 8-1000 keV band
is 8.5 +/- 0.5 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|