| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB090428441 |
|
| T0 |
10:34:38.271 UTC |
Fermi_GBM |
| ra |
210.1000° |
Fermi_GBM |
| decl |
39.5000° |
Fermi_GBM |
| pos_error |
4.54e+00° |
Fermi_GBM |
| T90 |
3.968 s |
Fermi_GBM |
| T90_error |
1.506 s |
Fermi_GBM |
| T90_start |
10:34:38.271 UTC |
Fermi_GBM |
| fluence |
1.04e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
6.27e-08 erg/cm² |
Fermi_GBM |
| T100 |
3.968 s |
|
| GBM_located |
True |
|
| mjd |
54949.440720729166 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB090428441 |
| trigger_name |
bn090428441 |
| ra |
210.1000° |
| decl |
39.5000° |
| pos_error |
4.54e+00° |
| datum |
2009-04-28 |
| t_trigger |
10:34:38.463 UTC |
| T90 |
3.968 s |
| T90_error |
1.506 s |
| T90_start |
10:34:38.271 UTC |
| fluence |
1.04e-06 erg/cm² |
| fluence_error |
6.27e-08 erg/cm² |
| flux_1024 |
6.29e+00 erg/cm²/s |
| flux_1024_error |
2.47e-01 erg/cm²/s |
| flux_1024_time |
1.02e+00 erg/cm²/s |
| flux_64 |
9.21e+00 erg/cm²/s |
| flux_64_error |
1.05e+00 erg/cm²/s |
| GCN 9294 table |
|---|
| GRB_name |
GRB090428A |
| GCN_number |
9294 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
10:34:38.460 UTC |
| ra |
212.4000° |
| decl |
37.3000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 9294
SUBJECT: GRB 090428: Fermi GBM detection
DATE: 09/04/29 15:20:35 GMT
FROM: Elisabetta Bissaldi at MPE
Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team:
"At 10:34:38.46 UT on 28 April 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090428 (trigger 262607680 / 090428441).
The on-ground calculated location, using the GBM trigger
data, is RA = 212.4, DEC = +37.3 (J2000 degrees,
equivalent to 14h 10m, 37d 18'), with an uncertainty
of 3.5 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 96 degrees.
The GBM light curve consists of two peaks
with a duration (T90) of about 8 s (8-1000 keV).
The time-averaged spectrum from T0-0.51 s to T0+2.04 s is
adequately fit by a power law function with an exponential
high energy cutoff. The power law index is -0.59 +/- 0.16
and the cutoff energy, parameterized as Epeak, is
97 +/- 7 keV (chi squared 471 for 485 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(9.9 +/- 1.4)E-07 erg/cm^2. The 128-msec peak photon flux measured
starting from T0+1.4 s in the 8-1000 keV band
is 12.3 +/- 1.9 ph/s/cm^2.
A Band function fits the spectrum equally well
(chi squared 468 for 484 d.o.f.) with Epeak = 85 +/- 10 keV,
alpha= -0.40 +/- 0.25 and beta = -2.7 +/- 0.4.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|