| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB220401429 |
|
| T0 |
10:17:38.331 UTC |
Fermi_GBM |
| ra |
9.9500° |
Fermi_GBM |
| decl |
52.7100° |
Fermi_GBM |
| pos_error |
5.44e+00° |
Fermi_GBM |
| T90 |
39.169 s |
Fermi_GBM |
| T90_error |
2.064 s |
Fermi_GBM |
| T90_start |
10:17:38.331 UTC |
Fermi_GBM |
| fluence |
6.37e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
3.65e-08 erg/cm² |
Fermi_GBM |
| T100 |
39.169 s |
|
| GBM_located |
True |
|
| mjd |
59670.428915868055 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB220401429 |
| trigger_name |
bn220401429 |
| ra |
9.9500° |
| decl |
52.7100° |
| pos_error |
5.44e+00° |
| datum |
2022-04-01 |
| t_trigger |
10:17:40.891 UTC |
| T90 |
39.169 s |
| T90_error |
2.064 s |
| T90_start |
10:17:38.331 UTC |
| fluence |
6.37e-06 erg/cm² |
| fluence_error |
3.65e-08 erg/cm² |
| flux_1024 |
7.82e+00 erg/cm²/s |
| flux_1024_error |
3.26e-01 erg/cm²/s |
| flux_1024_time |
6.98e+00 erg/cm²/s |
| flux_64 |
1.01e+01 erg/cm²/s |
| flux_64_error |
1.37e+00 erg/cm²/s |
| GCN 31811 table |
|---|
| GRB_name |
GRB220401A |
| GCN_number |
31811 |
| Detection_method |
Fermi GBM Other |
| ra |
8.0000° |
| decl |
50.0000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 31811
SUBJECT: GRB 220401A: Fermi GBM Final Localization
DATE: 22/04/01 17:40:40 GMT
FROM: Peter Veres at UAH
The Fermi GBM team reports the detection of a likely LONG GRB.
At 10:17:40.89 UT on 1 April 2022, the Fermi Gamma-ray Burst Monitor
(GBM) triggered and located GRB 220401A (trigger 670501065/
220401429). The trigger was initially classified as a Solar flare but
it is in fact a GRB.
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 8.0, Dec = 50.0 (J2000 degrees, equivalent to J2000 0h 3m, 50d
00'), with a statistical uncertainty of 4.2 degrees.
The angle from the Fermi LAT boresight is 82.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401429/quicklook/glg_skymap_all_bn220401429.png
The HEALPix FITS file, including the estimated localization
systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401429/quicklook/glg_healpix_all_bn220401429.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401429/quicklook/glg_lc_medres34_bn220401429.gif
|
| GCN 31816 table |
|---|
| GRB_name |
GRB220401A |
| GCN_number |
31816 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
10:17:40.890 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 31816
SUBJECT: GRB 220401A: Fermi GBM observation
DATE: 22/04/02 13:25:43 GMT
FROM: Peter Veres at UAH
P. Veres (UAH), E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 10:17:40.89 UT on 1 April 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220401A (trigger 670501065 / 220401429).
The localization was reported in GCN 31811.
The GBM lightcurve consists of two emission episodes
with a duration (T90) of about 39.2 s (50-300 keV).
The time-averaged spectrum from T0-8.2 s to T0+38.9 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.37 +/- 0.08
and the cutoff energy, parameterized as Epeak, is 46 +/- 2 keV.
The event fluence (10-1000 keV) in this time interval is
(2.42 +/- 0.06)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.0 s in the 10-1000 keV band
is 7.8 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
|
| GCN 31817 table |
|---|
| GRB_name |
GRB220401A |
| GCN_number |
31817 |
| Detection_method |
Swift Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 31817
SUBJECT: GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
DATE: 22/04/02 22:50:45 GMT
FROM: Aaron Tohuvavohu at U Toronto
Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), James DeLaunay
(UAlabama), Jamie A. Kennea (PSU), report:
Swift/BAT did not localize GRB 220401A onboard (T0: 2022-04-01T10:17:40
UTC, Fermi/GBM GCN 31811, 31816).
The Fermi notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 10.1 in a
1.024 s analysis time bin.
Only the peak of the second emission episode (at ~T0+35s) is clearly
detected in BAT.
NITRATES results are consistent with a burst coming from outside the
coded FoV, as indicated by the Fermi/GBM localization (GCN 31816).
See Section 9.1 and Figure 20 in the NITRATES paper for brief
descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.
GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/
|