| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB090425377 |
|
| T0 |
9:03:30.567 UTC |
Fermi_GBM |
| ra |
118.6000° |
Fermi_GBM |
| decl |
68.1000° |
Fermi_GBM |
| pos_error |
3.22e+00° |
Fermi_GBM |
| T90 |
75.393 s |
Fermi_GBM |
| T90_error |
2.45 s |
Fermi_GBM |
| T90_start |
9:03:34.151 UTC |
Fermi_GBM |
| fluence |
1.81e-05 erg/cm² |
Fermi_GBM |
| fluence_error |
1.52e-07 erg/cm² |
Fermi_GBM |
| T100 |
78.977 s |
|
| GBM_located |
True |
|
| mjd |
54946.377437118055 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB090425377 |
| trigger_name |
bn090425377 |
| ra |
118.6000° |
| decl |
68.1000° |
| pos_error |
3.22e+00° |
| datum |
2009-04-25 |
| t_trigger |
9:03:30.567 UTC |
| T90 |
75.393 s |
| T90_error |
2.45 s |
| T90_start |
9:03:34.151 UTC |
| fluence |
1.81e-05 erg/cm² |
| fluence_error |
1.52e-07 erg/cm² |
| flux_1024 |
1.39e+01 erg/cm²/s |
| flux_1024_error |
4.24e-01 erg/cm²/s |
| flux_1024_time |
6.09e+01 erg/cm²/s |
| flux_64 |
1.86e+01 erg/cm²/s |
| flux_64_error |
1.65e+00 erg/cm²/s |
| GCN 9271 table |
|---|
| GRB_name |
GRB090425A |
| GCN_number |
9271 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
9:03:30.570 UTC |
| ra |
116.1000° |
| decl |
69.9000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 9271
SUBJECT: GRB 090425: Fermi GBM detection
DATE: 09/04/27 16:10:11 GMT
FROM: Andreas von Kienlin at MPE
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 09:03:30.57 UT on 25 April 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090425 (trigger 262343012 / 090425377).
The on-ground calculated location, using the GBM trigger
data, is RA = 116.1, DEC = 69.9 (J2000 degrees,
equivalent to 07h 44m, 69d 54'), with an uncertainty
of 2.9 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 105 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.
The GBM light curve consists of three widely separated pulses
and has a duration (T90) of about 72 s (8-1000 keV).
The first two pulses at T0-0.6 s and T0+44 s are weak and
well fit by a simple power law functions with index -1.5 +/- 0.1
and index -1.7 +/- 0.1 respectively. The third pulse observed at
T0+57 s is strong and structured.
The time-averaged spectrum from T0+57.537 s to T0+80.065 s is
well fit by a power law function with an exponential high energy cutoff.
The power law index is -1.56 +/- 0.04 and the cutoff energy,
parameterized as Epeak, is 142 +/- 13 keV
(chi squared 570 for 484 d.o.f.).
A Band function fits the spectrum equally well
(chi squared 566 for 483 d.o.f.) with Epeak= 69 +/- 11 keV,
alpha = -1.29 +/- 0.11 and beta = -2.03 +/- 0.05.
The event fluence (8-1000 keV) in this time interval is
(1.3 +/- 0.2)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+57.537 s in the 8-1000 keV band
is 14.0 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
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