GRB 220311A
GCN Circular 31760
Subject
GRB 220311A: Fermi GBM observation
Date
2022-03-15T14:57:05Z (5 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 16:33:18.40 UT on 11 March 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220311A (trigger 668709203 / 220311690), which
was also detected by the INTEGRAL/IBAS (Mereghetti et al. 2022, GCN 31740).
The Fermi GBM Final Real-time Localization (GCN 31744) is largely
consistent with the INTEGRAL position.
The angle from the Fermi LAT boresight at the GBM trigger time is 111
degrees.
The GBM light curve shows a single spike with a duration (T90) of about
10 s (50-300 keV). The time-averaged spectrum from
T0-5.1 s to T0+0.0 s is adequately a simple power law function with index
-1.55 +/- 0.11.
The event fluence (10-1000 keV) in this time interval is
(1.8 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-4.7 s in the 10-1000 keV band
is 1.8 +/- 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 Circular 31757
Subject
GRB 220311A: MITSuME Akeno optical upper limits
Date
2022-03-15T02:22:55Z (5 years ago)
From
Ryohei Hosokawa at Tokyo Institute of Technology <hosokawa@hp.phys.titech.ac.jp>
R. Hosokawa, Y. Imai, R. Yamaguchi, K. L. Murata, M. Niwano, N. Ito,
Y. Takamatsu, R. Noto, S. Sato, M. Takaku, Y. Yatsu, and N. Kawai
(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 220311A (The Fermi GBM team GCN Circular
#31740, V. Yurkov et al. GCN Circular #31741, V. Lipunov et al. GCN
Circular #31742, V. Lipunov et al. GCN Circular #31743, S.Mereghetti
et al. GCN Circular #31744, V. Lipunov et al. GCN Circular #31745)
with the optical three color (g', Rc, and Ic) CCD cameras attached to
the MITSuME 50 cm telescope Akeno. The observation with a series of 60
sec exposures started at 2022-03-11 16:44:51 UT (11.7 minutes after
IBAS trigger). We stacked the images with good conditions. We did not
detect any uncatalogued sources within the IBAS error region
(S.Mereghetti et al. GCN Circular #31744). We obtained the 5-sigma
limits of the stacked images as follows.
T0+[min] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
29.0 2022-03-11 17:02:10 1440 g'>19.8, Rc>19.8, Ic>19.0
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used PS1 catalog for flux calibration.
The magnitudes are expressed in the AB system.
The images were processed in real-time through the MITSuME GPU
reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages
4-24; https://github.com/MNiwano/Eclaire).
GCN Circular 31745
Subject
GRB 220311A: MASTER OT retraction
Date
2022-03-11T19:50:59Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov (Lomonosov MSU)
The published OT candidate (GCN Circ 31741