GRB 220417A
GCN Circular 31912
Subject
GRB 220417A: Fermi GBM Final Real-time Localization
Date
2022-04-17T14:04:01Z (3 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 13:52:35 UT on 17 Apr 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220417A (trigger 671896360.964484 / 220417578).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 107.7, Dec = 11.3 (J2000 degrees, equivalent to J2000 07h 10m, 11d 18'), with a statistical uncertainty of 8.2 degrees.
The angle from the Fermi LAT boresight is 99.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220417578/quicklook/glg_skymap_all_bn220417578.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/bn220417578/quicklook/glg_healpix_all_bn220417578.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220417578/quicklook/glg_lc_medres34_bn220417578.gif
GCN Circular 31913
Subject
Fermi GRB 220417A: Global MASTER-Net observations report
Date
2022-04-17T17:30:19Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko,
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 220417A ( Fermi GBM team, GCN 31912) errorbox 10933 sec after notice time and 10962 sec after trigger time at 2022-04-17 16:55:18 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -9.1 deg.
The galactic latitude b = 10 deg., longitude l = 205 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1945725
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
10992 | 2022-04-17 16:55:18 | MASTER-SAAO | (07h 06m 38.28s , +08d 45m 24.4s) | C | 60 | 15.9 |
11072 | 2022-04-17 16:56:38 | MASTER-SAAO | (07h 14m 48.63s , +08d 45m 35.3s) | C | 60 | 16.3 |
11163 | 2022-04-17 16:58:09 | MASTER-SAAO | (07h 09m 06.34s , +10d 41m 17.1s) | C | 60 | 16.4 |
11254 | 2022-04-17 16:59:40 | MASTER-SAAO | (06h 59m 49.61s , +14d 29m 20.8s) | C | 60 | 16.4 |
11334 | 2022-04-17 17:00:59 | MASTER-SAAO | (07h 07m 58.48s , +14d 28m 42.2s) | C | 60 | 16.7 |
11509 | 2022-04-17 17:03:54 | MASTER-SAAO | (07h 17m 16.46s , +10d 40m 40.1s) | C | 60 | 17.0 |
11600 | 2022-04-17 17:05:25 | MASTER-SAAO | (07h 11m 57.99s , +12d 33m 45.2s) | C | 60 | 17.1 |
11679 | 2022-04-17 17:06:45 | MASTER-SAAO | (07h 20m 15.06s , +12d 34m 06.3s) | C | 60 | 17.2 |
11771 | 2022-04-17 17:08:16 | MASTER-SAAO | (06h 56m 29.96s , +12d 35m 39.7s) | C | 60 | 17.2 |
11862 | 2022-04-17 17:09:47 | MASTER-SAAO | (07h 04m 41.19s , +12d 34m 13.1s) | C | 60 | 17.4 |
11942 | 2022-04-17 17:11:07 | MASTER-SAAO | (07h 06m 46.87s , +08d 47m 40.7s) | C | 60 | 17.5 |
12033 | 2022-04-17 17:12:38 | MASTER-SAAO | (07h 14m 45.42s , +08d 46m 56.4s) | C | 60 | 17.6 |
12112 | 2022-04-17 17:13:58 | MASTER-SAAO | (07h 09m 05.17s , +10d 42m 00.2s) | C | 60 | 17.8 |
12204 | 2022-04-17 17:15:29 | MASTER-SAAO | (06h 59m 51.07s , +14d 29m 07.7s) | C | 60 | 17.9 |
12283 | 2022-04-17 17:16:49 | MASTER-SAAO | (07h 08m 01.35s , +14d 28m 11.3s) | C | 60 | 17.9 |
12374 | 2022-04-17 17:18:20 | MASTER-SAAO | (06h 53m 42.16s , +10d 41m 56.9s) | C | 60 | 18.0 |
12465 | 2022-04-17 17:19:50 | MASTER-SAAO | (07h 01m 50.54s , +10d 40m 34.4s) | C | 60 | 18.0 |
12545 | 2022-04-17 17:21:10 | MASTER-SAAO | (07h 17m 19.52s , +10d 42m 11.5s) | C | 60 | 18.2 |
12635 | 2022-04-17 17:22:40 | MASTER-SAAO | (07h 12m 01.86s , +12d 35m 19.6s) | C | 60 | 18.1 |
12714 | 2022-04-17 17:24:00 | MASTER-SAAO | (07h 20m 13.43s , +12d 36m 22.8s) | C | 60 | 18.2 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 31918
Subject
GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
Date
2022-04-19T05:16:43Z (3 years ago)
From
Aaron Tohuvavohu at U Toronto <aaron.tohu@gmail.com>
Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), James DeLaunay
(UAlabama), Jamie A. Kennea (PSU), report:
Swift/BAT did not localize GRB 220417A onboard (T0:
2022-04-17T13:52:35 UTC, Fermi/GBM trig #671896360).
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 12.8 in a
8.192 s analysis time bin.
The burst episode as seen by BAT is ~8s long.
NITRATES results are consistent with a burst coming from outside the
coded FoV, as indicated by the Fermi/GBM localization (GCN 31912).
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/
GCN Circular 31922
Subject
GRB 220417A: Fermi GBM detection
Date
2022-04-19T18:56:31Z (3 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 13:52:35.96 UT on 17 April 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220417A (trigger 671896360 / 220417578),
which was also detected by the Swift/BAT-GUANO (Raman et al. 2022,
GCN 31918).
The angle from the Fermi LAT boresight at the GBM trigger time is
99 degrees.
The GBM light curve shows a single peak with a duration (T90) of
about 17 s (50-300 keV). The time-averaged spectrum from T0-5.1 s
to T0+5.1 s is adequately fit by a power law function with an
exponential high-energy cutoff. The power law index is
0.51 +/- 0.57 and the cutoff energy, parameterized as Epeak,
is 431 +/- 97 keV.
The event fluence (10-1000 keV) in this time interval is
(2.5 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band is 1.3 +/- 0.2
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/"